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Provenancing People

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Abstract

This book provides the first comprehensive, overview and guide to forensic isotope analysis, an exciting new application of stable isotope analytical techniques. Topics are introduced using examples and real-life case studies such as food quality control where isotope analysis has already had a major impact, in terms of consumer protection, These examples illustrate the underlying principles of isotope profiling or fingerprinting. A section comprising actual criminal case work is used to build a bridge between the introduction and the technical section to encourage students to engage with this novel departure for analytical sciences while at the same time providing hands-on examples for the experienced researcher and forensic practitioner to match problems and success stories encountered with the topics discussed in the technical section. What little information is available on the subject in book form so far, has been published as individual chapters in books dealing either with mass spectrometry, forensic geoscience or environmental forensics, this is the first book to focus on the entire spectrum of forensic isotope analysis and will be an invaluable reference to both researchers in the field and forensic practitioners.

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... Few years later, Meier-Augenstein published an overview of the theory and principles underlying stable isotopes in addition to details on technical aspects and general considerations for the forensic application of IRMS. He also surveyed different forensic applications illustrated by the main ongoing research in the fields and some case studies234. Some of the main applications were presented by Chesson et al., from the point of view of isotope geochemists [5]. ...
... Except for pure illicit drugs, bulk analysis offers a less transparent result. Finally, a most peculiar and worrying issue is the far-fetched apparition of DR (dynamic range) notion to evaluate the evidentiary value of the isotopic profile of an ecstasy specimen stored in a database [4]. The ''Dynamic Range'' (DR, unitless) of the d value is defined ''as the isotopic range for a given suite of samples divided by the typical standard deviation of a replicate measurement of the same'' [4]. ...
... Finally, a most peculiar and worrying issue is the far-fetched apparition of DR (dynamic range) notion to evaluate the evidentiary value of the isotopic profile of an ecstasy specimen stored in a database [4]. The ''Dynamic Range'' (DR, unitless) of the d value is defined ''as the isotopic range for a given suite of samples divided by the typical standard deviation of a replicate measurement of the same'' [4]. By multiplying the DR for each isotope, the final figure provides the probability for a random match. ...
... Advances in Forensic Human Identification formation of late erupting molars, i.e. between 7 to 16 years of age. Using this value as an exclusion criterion, a process of elimination pointed towards the following different geographic regions as potential point of origin where the deceased lived during adolescence (Bell et al., 2009; Henton et al., 2010; LeeThorp, 2008; Meier-Augenstein, 2010). These locations included Southern/ South Western regions of Ireland, Southern/South Western regions of England, part of central France, near Mediterranean parts of Southern Europe and Eastern parts of the USA. ...
... The pooled averaged value for measured 13 C composition of tooth enamel was −12.2 ± 0.40‰. Accounting for the known isotopic shift between pooled 13 C composition of an individual's dietary intake and the 13 C isotopic composition of carbonate deposited during mineralisation, this value corresponds to a diet with an average 13 C composition of −22.70‰ (LeeThorpe, 2008; Meier-Augenstein, 2010). A dietary 13 C content of on balance −22.70‰ is typical for a diet with a considerable influence of C 4 plantsourced food products and food ingredients such as sweet corn, corn syrup or cane sugar as it is commonly observed for North Americans and people from most African countries. ...
... This is then dried, polished and sealed using a number of surface additives, selected for the particular purpose of the paper being produced. Isotopically, fractionation is defined as any chemical or physical reaction or process that shows a bias between the heavy and the light isotope [20]. These reactions are chemical in nature and occur due to differences in the physiochemical properties of molecules or during chemical reactions [21]. ...
Article
For casework applications, understanding the source processes used to create a material and the effects of those sources on the results obtained by Isotope Ratio Mass Spectrometry (IRMS) of a bulk material is important. Likewise, understanding the effect of environment, home/office printing processes and some forensic testing in at least a basic context, ensures that in casework, enough information on the effects of these variables is available during comparison and interpretation. In this study, which focuses on oxygen isotopic abundance measurements, both fractionation and mixing effects were observed within the pulping and production process. Also observed in the carbon isotopic experiments, sampling that included toner changed the measured isotopic abundance values of the paper and should be avoided in casework. Inkjet printing processes were not shown to have an effect on the paper oxygen abundance values. Samples that were treated for fingerprints using 1,2-Indandione-Zn prior to sampling showed the greatest risk for misinterpretation of whether two samples had originated from the same source. While this study provides a good basis and understanding of the effects of a range of factors on document paper oxygen isotope values, further testing for a range of specific casework scenarios is required and should be undertaken on a case by case basis as the need arises. Crown Copyright
... Applications of δ 2 H measurements, and to a lesser extent δ 18 O measurements, in studies involving animals has increased tremendously through the linkage of spatial patterns in amountweighted precipitation δ 2 H and δ 18 O values (i.e., isoscapes) with those in animal tissues, especially metabolically inert tissues such as keratins (e.g., feathers, hair, claws) and chitins (e.g., insect wings) (Hobson and Wassenaar, 2008). Such linkage has made it possible to track movements and origins of a broad range of migratory animals, and also provides the foundation for forensic approaches to tracing origins of various animal-and plantbased materials (Bowen et al., 2005b; Meier-Augenstein, 2011). Because tissue H and O isotopic composition is influenced by diet in addition to environmental water, the application of these isotopes can also be used as a tracer of organismal food and resource use. ...
Article
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The measurement of stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes in tissues of organisms has formed the foundation of isotopic food web reconstructions, as these values directly reflect assimilated diet. In contrast, stable hydrogen (δ²H) and oxygen (δ¹⁸O) isotope measurements have typically been reserved for studies of migratory origin and paleoclimate reconstruction based on systematic relationships between organismal tissue and local environmental water. Recently, innovative applications using δ²H and, to a lesser extent, δ¹⁸O values have demonstrated potential for these elements to provide novel insights in modern food web studies. We explore the advantages and challenges associated with three applications of δ²H and δ¹⁸O values in food web studies. First, large δ²H differences between aquatic and terrestrial ecosystem end members can permit the quantification of energy inputs and nutrient fluxes between these two sources, with potential applications for determining allochthonous vs. autochthonous nutrient sources in freshwater systems and relative aquatic habitat utilization by terrestrial organisms. Next, some studies have identified a relationship between δ²H values and trophic position, which suggests that this marker may serve as a trophic indicator, in addition to the more commonly used δ¹⁵N values. Finally, coupled measurements of δ²H and δ¹⁸O values are increasing as a result of reduced analytical challenges to measure both simultaneously and may provide additional ecological information over single element measurements. In some organisms, the isotopic ratios of these two elements are tightly coupled, whereas the isotopic disequilibrium in other organisms may offer insight into the diet and physiology of individuals. Although a coherent framework for interpreting δ²H and δ¹⁸O data in the context of food web studies is emerging, many fundamental uncertainties remain. We highlight directions for targeted research that will increase our understanding of how these markers move through food webs and reflect ecological processes.
... In recent years, segmental stable isotope analysis of hair has been a research focus of animal dietary ecology and migration.1234567The isotope abundance of 2 H and 18 O in animal tissue (including hair) provides information on water intake, which is a reflection of the geographical location, and the isotope abundance of 13 C and 15 N provides information on diet and nutritional status.[8,9]Tail hair is an ideal matrix for stable isotope analysis because it grows continuously in many species and is isotopically inert after formation.101112Consequently, ...
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RATIONALE: In recent years, segmental stable isotope analysis of hair has been a focus of research in animal dietary ecology and migration. To correctly assign tail hair segments to seasons or even Julian dates, information on tail hair growth rates is a key parameter, but is lacking for most species. METHODS: We (a) reviewed the literature on tail hair growth rates in mammals; b) made own measurements of threecaptive equid species; (c) measured δ2H, δ13C and δ15N values in sequentially cut tail hairs of three sympatric, free-ranging equids from the Mongolian Gobi, using isotope ratio mass spectrometry (IRMS); and (d) collected environmental background data on seasonal variation by measuring δ2H values in precipitation by IRMS and by compiling pasture productivity measured by remote sensing via the normalized difference vegetation index (NDVI). RESULTS: Tail hair growth rates showed significant inter- and intra-specific variation making temporal alignment problematic. In the Mongolian Gobi, high seasonal variation of δ2H values in precipitation results in winter lows and summer highs of δ2H values of available water sources. In water-dependent equids, this seasonality is reflected in the isotope signatures of sequentially cut tails hairs. CONCLUSIONS: In regions which are subject to strong seasonal patterns we suggest identifying key isotopes which show strong seasonal variation in the environment and can be expected to be reflected in the animal tissue. The known interval between the maxima and minima of these isotope values can then be used to correctly temporally align the segmental stable isotope signature for each individual animal. © 2015 The Authors. Rapid Communications in MassSpectrometry published by John Wiley & Sons Ltd.
... Pollen grains also could be a particularly important marker of objects that have moved between locations, for example if a laptop has been moved from Denmark to Bolivia to Oregon USA. More fine-scale environmental profiling is likely to be obtained by combining pollen DNA barcoding with other forensic techniques, for example stable isotope analyses [19]. Reviews of the use of forensic palynology [10,11] discuss the potential of the technique, but recognize that its use is currently limited. ...
... The fact that hair and nail grow at known rates can be exploited to obtain chronological information that can be used to detect and monitor substance use, to detect exposure to xenobiotics (drugs, solvents , etc.) in a person's environment (e.g., place of work), and even to reconstruct a person's recent life trajectory, which in turn can aid with victim identification Disaster Victim Identification but also has applications in the investigation of people trafficking and combating terrorism [1] [2] [3] [4] [5] [6] [7] [8] [9]. While methods to categorize and compare hair on the basis of morphology , taxonomy, trace chemical composition, and mitochondrial DNA have been established and used for more than 20 years [1, 10–13], the ability to reconstruct a person's recent life history or life trajectory in terms of changes in dietary intake and geographical movement based on the sequential stable isotope analysis of hair and nail is largely due to the continued efforts of a handful of research groups during the last 10 years [3, 4, 8, 14–27]. ...
... In the peer reviewed scientific literature, Horacek et al. (2009) described the use of stable isotopes to successfully distinguish Siberian from European larch, and Kagawa and Leavitt (2010) achieved extremely fine spatial resolution when provenancing pinyon pines in the south-western United States using carbon isotopes from multiple tree rings in conjunction with dendrochronological data (see Section 2.1.2). Stable isotope analysis is generally gaining momentum as an established forensic tool, particularly in the food and drinks sector (Meier-Augenstein, 2011), and timber identification can benefit from its broader utility to provenance questions. ...
... The geographical signature from water is transferred into plant and animal products[64]. δ 15 N values have relatively shorter ranges but vary according to different factors: the nitrogen cycle (fixation, uptake, mineralization, nitrification, and denitrification), trophic ecology (an increase in trophic level correlates with an increase in δ 15 N value), and anthropogenic activity[65]. Finally, δ 34 S values are bound to sulfur sources such as bedrock weathering, atmospheric deposition, and microbiological activity. ...
Article
Full-text available
The food market nowadays accounts for huge incomes and therefore it is an easy target for falsification. This recalls the urgency for reliable and powerful diagnostic techniques, in order to develop analytical protocols for identification of frauds. MS-based strategies of analysis are definitely suitable for this task and have become in the last years of paramount importance in the field of food forensics. Sophisticated techniques have been developed that request short times of analysis and allow the identification of specific parameters, useful as classification markers. The wide range of techniques available (i.e., isotopic analysis, inductively coupled plasma-mass spectrometry (ICP-MS), hyphenated systems, stand-alone systems) allow to address a wide range of analytical questions pertaining to food authentication and traceability.
... This characteristic makes them an excellent source of information. Since the beginning of the twenty-first century, stable isotope forensics [2] [3] expanded the forensic tool set employed to help identify the " unidentifiables " . In using the term " unidentifiable " we refer to murder or disaster victims( Disaster Victim Identification ) where the circumstances prevent rapid victim identification by means of a DNA( Missing Persons and Paternity: DNA) or fingerprint database match, odontology( Odontology), distinguishing marks, or personal possessions. ...
Chapter
In most of the different body deposition scenarios but for cremation, bone and teeth are typically the human remains that remain intact the longest after death has occurred. In the absence of any distinguishing features or other evidence that could help with positive victim identification, stable isotope profiles or signatures can provide useful information about a person's diet and geographic life trajectory, which can bring focus to an investigation involving unidentified victims of serious crime or mass disasters. No matter what the case circumstance, victim identification is of paramount importance to provide closure for next of kin and to help dealing with legal processes ensuing from the death of a person. In cases of serious crime, identification of the victim is a major stepping stone toward identifying the perpetrator/s.Keywords:bioapatite;bone;carbonate;collagen;diet;forensic intelligence;geographic origin;human provenance;isotope ratio;victim identification;stable isotope profile
... The fact that hair and nail grow at known rates can be exploited to obtain chronological information that can be used to detect and monitor substance use, to detect exposure to xenobiotics (drugs, solvents , etc.) in a person's environment (e.g., place of work), and even to reconstruct a person's recent life trajectory, which in turn can aid with victim identification Disaster Victim Identification but also has applications in the investigation of people trafficking and combating terrorism [1] [2] [3] [4] [5] [6] [7] [8] [9]. While methods to categorize and compare hair on the basis of morphology , taxonomy, trace chemical composition, and mitochondrial DNA have been established and used for more than 20 years [1, 10–13], the ability to reconstruct a person's recent life history or life trajectory in terms of changes in dietary intake and geographical movement based on the sequential stable isotope analysis of hair and nail is largely due to the continued efforts of a handful of research groups during the last 10 years [3, 4, 8, 14–27]. ...
Chapter
While bone and teeth provide a long-term stable isotope record of a person's life history measured in years (see Stabel Isotope Analysis: Bone and Teeth), stable isotope profiles of hair and nail can yield information on a person's recent life circumstance up to 15 months into a person's past. Since hair and nail samples can be collected noninvasively, stable isotope profiles of these tissues may also be used to reveal information on recent geographic movement in living people. This information may prove useful to check on the veracity of a suspect's statement about their recent geographic movements.Keywords:diet;forensic intelligence;geographic movement;geographic origin;human provenance;keratin;isotope ratio;people trafficking;victim identification;stable isotope profile
... von skelettierten Überresten, werden zunächst die oben erwähnten herkömmlichen Methoden angewendet. Führen diese Methoden jedoch zu keinem Ergebnis , kann die Analyse der Isotopenverhältnisse von Bio-(beispielsweise der Elemente Wasserstoff, Sauerstoff, Kohlenstoff, Stickstoff und Schwefel) und Geoelementen (beispielsweise der Elemente Strontium und Blei) an Körpergeweben des Verstorbenen Informationen zur Herkunft und Migration liefern (Lehn, 2010, Lehn, 2014, Lehn and Graw, 2012a, Lehn and Graw, 2012b, Meier-Augenstein, 2010, Augenstein and Fraser, 2008, Rummel et al., 2007). Über die Ernährung und Umwelt werden unterschiedliche Verhältnisse dieser Elemente in den Körper eingebaut, die eine regional typische Isotopensignatur aufweisen . ...
Article
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Das Hauptaufgabengebiet der Forensischen Anthropologie ist die Identifikation von menschlichen Überresten oder lebenden Menschen anhand von biologischen Merkmalen. Bei dem zur Verfügung stehenden Material handelt es sich meist um skelettierte oder mumifizierte Überreste, aber auch der Bereich der „Lebendidentifikation“, beispielsweise das Untersuchen von Bildmaterial, wird von der Forensischen Anthropologie betreut. Im Falle der Bearbeitung von menschlichen Überresten werden ganze Skelette, einzelne Knochen und Knochenfragmente einer morphologischen und osteometrischen Begutachtung unterzogen, um die Zahl der in Frage kommenden vermissten Personen einzugrenzen.
... Estes são apresentados em unidades de por mil (‰). Os valores de delta podem ser calculados utilizando a seguinte fórmula: [19][32] δ = preparação de amostra, bem como, através de recipientes transparentes selados; especificidade, os modos de vibração são únicos para cada espécie química presente numa dada estrutura; e alta resolução espacial, somente limitada pelo critério de difracção de Rayleigh. Importante enfatizar que a espectroscopia Raman apresenta um caracter não destrutivo e não invasivo e tempos de análise rápidos. ...
Thesis
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A investigação forense dos constituintes dos diferentes tipos de solos é relevante, pois estes, muitas vezes, contêm adicionadas partículas. Estas partículas podem apresentarse como moléculas orgânicas e ácidos húmicos com um grande interesse forense. As adipoceras são grupos de moléculas orgânicas a partir das quais podemos saber se um corpo terá estado num determinado local. Neste trabalho analisaram-se os componentes de adipoceras em solos: ácido oleico, palmítico, esteárico ou mirístico, que são mais de 95% da sua composição, mediante a técnica de Espectrometria de massa de razão isotópica (IRMS), Análise térmica e Espectroscopia Raman. Pretendendo-se conjuntamente comprovar a influência dos solos nas diferentes relações isotópicas.
... Isotope hydrology caught up quickly (e.g., Craig, 1961 ), followed by stable isotope applications in biology and ecology (for comprehensive reviews see Ehleringer et al., 1993; Griffiths, 1998; Rundel et al., 1988). Today, stable isotope measurements have become an indispensable and integral part of environmental research from atmospheric measurement programs (e.g., Francey et al., 2001; Masarie et al., 2001; Trolier et al., 1996 ), through paleoclimate research (e.g., Emiliani, 1966; Zachos et al., 2001), and all the way to forensic applications (Meier-Augenstein, 2010). Efforts to develop analytical and numerical models that incorporate the cycling of stable isotopes in CO 2 expanded in parallel (e.g., Bolin, 1981; Ciais et al., 1995b Ciais et al., , 1997a Enting et al., 1995 ). ...
Chapter
About half of the CO2 emitted by fossil fuel combustion currently remains in the atmosphere. The other half is removed by CO2 uptake on land and in the ocean. Prediction of future CO2 concentrations relies critically on the understanding of these sources and sinks and their potential variability over time. While such understanding requires quantification of individual carbon fluxes, the means to achieve this in direct measurements are very limited. The isotopic composition of atmospheric CO2 provides a powerful and indispensable tool in that respect. This chapter reviews the methodological and observational basis underlying the use of the isotopic composition of atmospheric CO2 in tracing and interpreting the changes in sources and sinks of CO2 over seasonal, annual, and longer timescales, as well as over different spatial scales. The processes influencing the isotopic 'signatures' associated with specific processes in the contemporary carbon cycle and the usefulness of such signals are discussed. For example: How can annual-scale variations in 13C observations be used to partition CO2 uptake between land and ocean? Why does the decreasing trend in the 13C of atmospheric CO2 over the past 150 years (due to the addition of 13C-depleted CO2 to the atmosphere through fossil fuel combustion) provide an indicator of the carbon turnover rate in the biosphere? Why does the 18O in atmospheric CO2 reflect variability in the plant versus soil fluxes within the land biosphere? Finally, the new frontiers in the application of isotopic analysis of atmospheric CO2, such as the use of laser spectroscopy, our ability to identify variations in the rare, isotopically doubly labeled CO2 molecules (e.g., containing both 13C and 18O), and the measurement of the 17O anomaly in CO2, are explored.
... Ammonium nitrate samples were analyzed as described in No additive + sugar 1:1 + graphi te 1:1 our extensive drying procedure and despite containing the MAS 200R autosampler in a box flushed with argon, our setup is not completely closed and some water absorption may have occurred. The use of a 'zero-blank' autosampler [52] may prevent water absorption and reduce the between-sequence variability. ...
... Where traditional methods of identifying a person (e.g. tracing the dental chart, DNA analysis, soft tissue reconstruction of the face) fail, the results of the analysis of the stable isotope abundance ratios (isotope ratios) of the bio-elements (H, O, C, N, S) and geo-elements (Sr, Pb) in body tissues of the dead person can provide clues for further police investigations [1][2][3][4][5][6][7][8][9]. Depending on the geographical and geological situation, plants and living organisms display different isotope ratios with certain regional isotope patterns. ...
Article
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Stable isotope methods can be used to determine the provenance of unidentified corpses. Body tissue materials such as teeth, bone, hair and nail taken from mortal remains provide information of different time periods of an individuals' life from childhood to death. Tissues of newborns contain provenance information of different time periods during pregnancy of the child's mother.The results of stable isotope analyses of body residues of two adults and a newborn found in Germany between 2010 and 2012 are presented. To determine the geographic origin and movements of unknown individuals, stable isotopes of hydrogen, carbon, nitrogen and sulphur were analysed in hair and bone collagen samples. Amino acid composition and, as a consequence, δ2H, δ13C, δ15N, and δ34S values in human keratin and bone collagen are different. Consequently correction factors were determined to compare isotopic data of bone collagen with those of an extensive worldwide reference hair collection. The isotopic signatures in hair and in bone collagen samples were compared to geographical groups of reference hair samples by canonical discriminant analysis. The results served as the basis for providing provenance constraints for the unidentified persons as requested by the police and prosecution. Ultimately the individuals were identified; hence the isotopic provenance interpretations can be critically evaluated and are shown to be successful.
Chapter
Atmospheric testing of nuclear weapons during the 1950s and early 1960s doubled the concentration of carbon-14 in the atmosphere and created a pulse that labeled everything alive since 1955 as carbon moved up the food chain. The variation in carbon-14 concentration in time is well-documented and can be used to chronologically date all biological materials since the mid-1950s.
Thesis
Racism as a social institution has played an important role in shaping ethnic identities throughout the history of the United States. These identities are changeable through ethnogenesis in a polycultural framework, and are constantly having to renegotiate themselves according to personal interactions with others and with the greater sociopolitical environment at large. Foodways are an important part of ethnic identity as they are a way of acting out social relationships and form a large part of day-to-day habits. In Santa Clara County from 1870 to 1935, the social environment was ripe with potential for change due to race-based barriers. Despite this, the Santa Clara Valley Medical Center and its associated potter’s field provided care and graves to the poor, indigent, and unclaimed of the County. This study examines the dietary patterns of inhabitants of Santa Clara County to see if there was an aggregation of foodways in the community, or if diet maintained distinctness between ethnic groups in this multi-national community, even while generating new foodways unique to the rest of the United States. This study conducted ancestry assessment and stable isotope analysis on a sample of 50 individuals from the Santa Clara Valley Medical Center potter’s field collection to evaluate the hypotheses. The results suggested that there are no significant differences in diet between ancestry groups. However, there are significant differences between the sample and other regions of the U.S. It is unclear, however, if these differences are a result of socioeconomic status, local agricultural industry, or both. This thesis suggests that both likely play a factor, and that being poor may have played a more important role in food habits than racial barriers for those interred at the Santa Clara Valley Medical Center potter’s field.
Chapter
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Recent forensic applications of stable isotope analysis (SIA) have demonstrated its value as an investigative tool in the identification of unknown decedents. Stable isotope ratios measured in bones, teeth, hair, and nails provide a record of a person’s dietary preferences, travel history, and residence patterns. Stable carbon, nitrogen, and sulfur isotopes of human tissues provide information regarding a decedent’s dietary preferences, which in turn may reflect a person’s geographic region of origin. Additionally, stable oxygen and strontium isotopes in body tissues can be used to provenance human remains, because these isotopes reflect the source of drinking water and local geology, respectively. When combined, a multi-isotope approach provides a powerful geolocation tool for predicting a region of origin or recent travel history for unidentified human remains. In this study, we present on two forensic cases that used SIA to predict the travel history and region of origin of unknown decedents.
Article
The compound specific isotope analysis is nowadays an important and powerful tool in geochemical, environmental and forensics field. On November 2013, Aqli Foods Corporation in Japan dealt with complaints about stench from frozen foods produced. Subsequently, very high concentrations of organophosphorus pesticide as malathion, ethylbenzene and xylene were detected in recovered frozen foods. In particular case, we present the method to measure the stable carbon isotope ratio (δ¹³C) of nine malathion emulsion pesticides using gas chromatography/isotope ratio mass spectrometry (GC/IRMS) to identify the source. The δ¹³C values of malathion ranged from − 30.6‰ to − 29.5‰. Because malathion used in all malathion emulsions sold in Japan is imported from the same overseas company, Cheminova, Denmark. The δ¹³C values of ethylbenzene ranged from − 28.2‰ to − 20.8‰ and those of m,p-xylene from − 28.7‰ to − 25.2‰. The differences in the δ¹³C values may be because of the material itself and chemical processing. We also determined the ratio of ethylbenzene to m,p-xylene and finally categorized the nine malathion samples into five groups on the basis of this ratio and the δ¹³C values of ethylbenzene and m,p-xylene. The results of isotopic fractionation during volatilization (refrigerate, room temperature and incubator) was negligible small.
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Competition among sympatric wild herbivores is reduced by different physiological, morphological and behavioural traits resulting in different dietary niches. Wild equids are a rather uniform group of large herbivores which have dramatically declined in numbers and range. Correlative evidence suggests that pasture competition with livestock is one of the key factors for this decline, and the situation may be aggravated in areas where different equid species overlap. The Dzungarian Gobi is currently the only place where two wild equid species coexist and share the range with the domesticated form of a third equid species. In the winter‐cold Gobi desert pasture productivity is low, highly seasonal, and wild equids additionally face increasing livestock densities. We used stable isotope chronologies of tail hairs to draw inferences about multi‐year diet seasonality, isotopic dietary niches and physiological adaptations in the Asiatic wild ass (khulan), re‐introduced Przewalski's horse, and domestic horse in the Mongolian part of the Dzungarian Gobi. Our results showed that even in the arid Gobi, both horse species are predominantly grazers, whereas khulan are highly seasonal, switching from being grazers in summer to mixed feeders in winter. The isotopic dietary niches of the two horse species were almost identical, did not vary with season as in khulan and were narrower than in the latter. Higher δ¹⁵N values point towards higher water use efficiency in khulan, which may be one reason why they can exploit pastures further away from water. Synthesis and applications. The high degree of isotopic dietary niche overlap in the two horse species in the Mongolian Gobi points towards a high potential for pasture competition during the critical nutritional bottleneck in winter and highlights the need to severely restrict grazing of domestic horses on the range of the Przewalski's horses. The evolutionary more distant khulan are less constrained by water and seem more flexible in their choice of diet or less successful in exploiting grass‐dominated habitats in winter due to human presence. Providing additional water sources could increase the competition between khulan and livestock and should, therefore, only be done following careful consideration.
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A geostatistical model to predict human skeletal oxygen isotope values (δ18Op) in Britain is presented here based on a new dataset of Chalcolithic and Early Bronze Age human teeth. The spatial statistics which underpin this model allow the identification of individuals interpreted as ‘non-local’ to the areas where they were buried (spatial outliers). A marked variation in δ18Op is observed in several areas, including the Stonehenge region, the Peak District, and the Yorkshire Wolds, suggesting a high degree of human mobility. These areas, rich in funerary and ceremonial monuments, may have formed focal points for people, some of whom would have travelled long distances, ultimately being buried there. The dataset and model represent a baseline for future archaeological studies, avoiding the complex conversions from skeletal to water δ18O values–a process known to be problematic.
Article
Studying links between triacetone triperoxide (TATP) samples from crime scenes and suspects can assist in criminal investigations. Isotope ratio mass spectrometry (IRMS) and gas chromatography (GC)-IRMS were used to measure the isotopic compositions of TATP and its precursors acetone and hydrogen peroxide. In total, 31 TATP samples were synthesized with different raw material combinations and reaction conditions. For carbon, a good differentiation and a linear relationship were observed for acetone-TATP combinations. The extent of negative (δ(13) C) fractionation depended on the reaction yield. Limited enrichment was observed for the hydrogen isotope (δ(2) H) values of the TATP samples probably due to a constant exchange of hydrogen atoms in aqueous solution. For oxygen (δ(18) O), the small isotopic range and excess of water in hydrogen peroxide resulted in poor differentiation. GC-IRMS and IRMS data were comparable except for one TATP sample prepared with high acid concentration demonstrating the potential of compound-specific isotope analysis. Carbon IRMS has practical use in forensic TATP investigations.
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Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.
Article
Skeletonized human remains of an elderly, unknown man, packed in a suitcase, were found in Berlin, Germany. Determination of geographical whereabouts and living circumstances of the unknown person was possible by stable isotope analyses of the bio- and geo-elements (H, C, N, S, Sr, Pb) in teeth, bones and hair. After the man had been identified, it was possible to compare the statements of the isotope report with his life history. It was found that the isotope data correspond well with personal living conditions, not only with respect to geographical whereabouts and dietary habits during different stages of life, but also to health status during the last months of life.
Chapter
Because of the Nazis’ attempts to hide their crimes and landscape change since the end of the Second World War, much of the evidence of the Holocaust has been deliberately or naturally buried or concealed. Once a thorough assessment of any surviving above-ground evidence has been undertaken (Chap. 6), various methods can be employed to assess what lies below the ground. Assessing this evidence need not mean that invasive work has to be undertaken, given the variety of geophysical techniques that now exist. Equally, when invasive work is undertaken, it should be remembered that a wide range of evidence types can be recovered and analysed through various novel methods derived from archaeology and forensic science. This chapter provides a review of the methods that should be considered when assessing buried remains and the specific challenges associated with them when addressing the physical evidence of the Holocaust.
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Oxygen isotope ratios of organisms are closely linked to the hydrological environment in which they grow up. This is especially the case for mammals. Mammal-bone phosphate is formed at a constant body temperature and, thus, relatively insensitive to temperature-dependent isotope fractionation. The applicability of oxygen isotopes from mammal-bone phosphate for environmental reconstructions is tested here using bones of deer, domestic pig and domestic cattle from 16 archaeological sites situated along a North-South transect crossing the Alps. Bones of 118 specimens in total were analyzed, which covered an age span from the Late Neolithic to the Roman period. The main control on oxygen isotope ratios was site altitude. Significant negative correlations between phosphate-isotope values and altitude were registered especially for cattle and pig. Pig bones from one site were deviating from this altitudinal pattern and were excluded from further correlations. Modern equations for translating oxygen-isotope ratios of the three species to those of source water were applied. The reconstructed source-water isotopic composition showed a similar altitudinal relation as modern Alpine precipitation. As a consequence, our study confirms the utility of oxygen-isotope ratios of mammal-bone phosphate for source water and palaeoaltitudinal reconstructions.
Article
Attribution of the origin of an illicit drug relies on identification of compounds indicative of its clandestine production and is a key component of many modern forensic investigations. The results of these studies can yield detailed information on method of manufacture, starting material source, and final product - all critical forensic evidence. In the present work, chemical attribution signatures (CAS) associated with the synthesis of the analgesic fentanyl, N-(1-phenylethylpiperidin-4-yl)-N-phenylpropanamide, were investigated. Six synthesis methods, all previously published fentanyl synthetic routes or hybrid versions thereof, were studied in an effort to identify and classify route-specific signatures. 160 distinct compounds and inorganic species were identified using gas and liquid chromatographies combined with mass spectrometric methods (GC-MS and LC-MS/MS-TOF) in conjunction with inductively coupled plasma mass spectrometry (ICP-MS). The complexity of the resultant data matrix urged the use of multivariate statistical analysis. Using partial least squares discriminant analysis (PLS-DA), 87 route-specific CAS were classified and a statistical model capable of predicting the method of fentanyl synthesis was validated and tested against CAS profiles from crude fentanyl products deposited and later extracted from two operationally relevant surfaces: stainless steel and vinyl tile. This work provides the most detailed fentanyl CAS investigation to date by using orthogonal mass spectral data to identify CAS of forensic significance for illicit drug detection, profiling, and attribution.
Article
The relationship between isotopic signals in human hair and geographic region has potential forensic applications for identifying unknown individuals' place of recent residence. This study analyzes δ2H and δ18O isotopes in residential tap water and bulk hair samples from 17 volunteers representing 12 locations in Ontario, Canada. There is a strong correlation (R2 = 0.9) between δ2H and δ18O values of the water samples. In contrast, the δ2H and δ18O values of the hair samples are weakly correlated (R2 = 0.3), and the greater variability in the data is linked to dietary factors. This study demonstrates that the δ2H and δ18O values of hair and drinking water can be used to help identify potential place of residence in forensic cases, particularly in relation to proximity to large bodies of water such as the Great Lakes, but interpretations are complicated by the contribution of both water and diet to δ2H and δ18O values in hair.
Chapter
Stable isotope ratio analysis of human hair has the potential to provide a wealth of information about nutritional status, metabolism and disease states. While applications are relatively new in clinical nutrition and metabolic studies, the study of natural isotope abundances in hair have been routinely applied to archaeological and ecological research for over the past 30 years. As human hair is relatively non-invasive to sample and can linear record isotopic signatures over time, there is great promise that this technique will be fully developed at both the bulk protein and amino acid level to provide an unbiased method or biomarker for the detection nutritional status, geographical location, health, and disease patterns in humans.
Article
Burned skeletal material is often very fragile and at high risk for fragmentation during packaging and transportation. One method that has been suggested to protect bones in these cases is to carefully wrap them in aluminum foil. Traces of aluminum, however, are known to transfer from foil packaging materials to food products. If such transfer occurs between aluminum foil and bones, it could interfere with subsequent chemical, elemental and isotopic analyses, which are becoming more common in forensic anthropological investigations. This study examined aluminum levels in bones prior to and following the use of aluminum foil packaging and storage for a 6-week period. Results indicate no significant change in the detected levels of aluminum (p > 0.05), even when packaged in compromised foil and exposed to elevated temperatures. Aluminum foil can therefore continue to be recommended as a packaging medium without affecting subsequent chemical examinations.
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Mummies are faunal remains that include the preservation of soft tissues, such as skin, muscle, nails and hair as well as bone. These soft tissues are generally rich in collagen or keratin proteins and thus provide potentially suitable material for stable isotope studies. When preserved, such tissues can provide high-resolution information about the diet and migration of humans in the weeks and months before death. Hair, nails and soft tissue provide short-term (months) dietary information in contrast to bone which will represent 5–20 years of dietary history prior to death, depending on the bone analysed. Such high-resolution data can answer questions on the season of death, seasonality of food resources and the movement and relocation of people. This review begins with a summary of the most common isotope techniques (13 C/ 12 C, 15 N/ 14 N) and the tissues concerned, followed by an analysis of the key questions that have been addressed using these methods. Until relatively recently work has focused on bulk protein isotope analysis, but in the last 10 years this has been expanded to on-line compound-specific amino acid analysis and to a wider variety of isotopes (18 O/ 16 O, 2 H/ 1 H and 34 S/ 32 S) and these applications are also discussed.
Article
Stable isotope analysis has a lengthy application history in the fields of biology, ecology, and geology but its application in forensic investigations is relatively new. A recent report by the National Research Council on the strength of the forensic sciences in the United States highlighted areas of weakness, including the lack of a tested scientific foundation for many of the analytical techniques used in examinations. Stable isotope analysis has a strong scientific foundation developed in the academic community and could thus play a major role in the forensic community as a powerful tool in the investigator's toolbox.This chapter presents a framework for applying the stable isotope analysis techniques commonly employed by isotope geochemists in forensics settings. The utility of this framework lies in its ability to address a range of questions from relatively simple sample comparisons to more complex region or origin predictions. The forensic application of stable isotope analysis within this framework is discussed at both a nonspatial and spatial scale, examples of applications include the analysis of nonorganic and organic materials. The chapter concludes with a discussion detailing how the stable isotope analysis techniques developed in scientific settings can be extremely useful in legal settings as well.
Chapter
Introduction Molecular Mass Spectrometry Isotope Ratio Mass Spectrometry Ion Mobility Spectrometry Summary References
Book
This book aims to move archaeological research concerning the Holocaust forward through a discussion of the variety of the political, social, ethical and religious issues that surround investigations of this period and by considering how to address them. It considers the various reasons why archaeological investigations may take place and what issues will be brought to bear when fieldwork is suggested. It presents an interdisciplinary methodology in order to demonstrate how archaeology can (uniquely) contribute to the history of this period. Case examples are used throughout the book in order to contextualise prevalent themes and a variety of geographically and typologically diverse sites throughout Europe are discussed. This book challenges many of the widely held perceptions concerning the Holocaust, including the idea that it was solely an Eastern European phenomena centred on Auschwitz and the belief that other sites connected to it were largely destroyed or are well-known. The typologically, temporally and spatial diverse body of physical evidence pertaining to this period is presented and future possibilities for investigation of it are discussed.Finally, the volume concludes by discussing issues relating to the re-presentation of the Holocaust and the impact of this on commemoration, heritage management and education. This discussion is a timely one as we enter an age without survivors and questions are raised about how to educate future generations about these events in their absence.
Article
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RationaleNatural stable carbon (δ13C) and nitrogen isotope ratios (δ15N) of humans are related to individual dietary habits and environmental and physiological factors. In forensic science the stable isotope ratios of human remains such as hair and nail are used for geographical allocation. Thus, knowledge of the global spatial distribution of human δ13C and δ15N values is an essential component in the interpretation of stable isotope analytical results.Methods No substantial global datasets of human stable isotope ratios are currently available, although the amount of available (published) data has increased within recent years. We have herein summarised the published data on human global δ13C andδ15N values (around 3600 samples) and added experimental values of more than 400 additional worldwide human hair and nail samples. In order to summarise isotope ratios for hair and nail samples correction factors were determined.ResultsThe current available dataset of human stable isotope ratios is biased towards Europe and North America with only limited data for countries in Africa, Central and South America and Southeast Asia. The global spatial distribution of carbon isotopes is related to latitude and supports the fact that human δ13C values are dominated by the amount of C4 plants in the diet, either due to direct ingestion as plant food, or by its use as animal feed. In contrast, the global spatial distribution of human δ15N values is apparently not exclusively related to the amount of fish or meat ingested, but also to environmental factors that influence agricultural production.Conclusions There are still a large proportion of countries, especially in Africa, where there are no available data for human carbon and nitrogen isotope ratios. Although the interpretation of modern human carbon isotope ratios at the global scale is quite possible, and correlates with the latitude, the potential influences of extrinsic and/or intrinsic factors on human nitrogen isotope ratios have to be taken into consideration. Copyright © 2015 John Wiley & Sons, Ltd.
Article
Elemental analysis of calcium (Ca) and phosphorus (P) has been shown to be useful in differentiating skeletal and nonskeletal material. X-ray fluorescence spectrometry (XRF) is an attractive, nondestructive technique for forensic anthropologists, and the development of portable XRF instrumentation is promising for field applications. This study examines the performance of handheld XRF instrumentation operated in air compared to a traditional benchtop XRF device that has the ability to control the analysis atmosphere. Both instruments can be used to effectively distinguish skeletal from nonskeletal remains. However, as the measurement atmosphere affects detection levels for calcium and phosphorus, Ca/P ratios obtained from the instruments and analysis conditions were found to differ significantly, with analyses conducted in air showing significantly lower phosphorus detection. Consequently, comparison of Ca/P ratios to conclude skeletal versus nonskeletal origin must be based on data collected under similar analysis conditions.
Article
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Developments in forensic mass spectrometry tend to follow, rather than lead, the developments in other disciplines. Techniques of great forensic utility or potential born independently of forensic applications include ambient ionization, imaging mass spectrometry, isotope ratio mass spectrometry, portable mass spectrometers, and hyphenated chromatography-mass spectrometry instruments, to name a few. Forensic science has the potential to benefit enormously from developments that are funded by other means, if only the infrastructure and personnel existed to adopt, validate, and implement the new technologies into casework. Perhaps one unique area in which forensic science is at the cutting edge is in the area of chemometrics and the determination of likelihood ratios for the evaluation of the weight of evidence. Such statistical techniques have been developed most extensively for ignitable-liquid residue analyses and isotope ratio analysis. This review attempts to capture the trends, motivating forces, and likely impact of developing areas of forensic mass spectrometry, with the caveat that none of this research is likely to have any real impact unless: (a) The instruments developed are turned into robust black boxes with red and green lights for positives and negatives, respectively, or (b) there are PhD graduates in the workforce who can help adopt these sophisticated techniques. Expected final online publication date for the Annual Review of Analytical Chemistry Volume 8 is June 15, 2015. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Article
Diet is a leading modifiable risk factor for chronic disease, but it remains difficult to measure accurately due to the error and bias inherent in selfreported methods of diet assessment. Consequently, there is a pressing need for more objective biomarkers of diet for use in health research. The stable isotope ratios of light elements are a promising set of candidate biomarkers because they vary naturally and reproducibly among foods, and those variations are captured in molecules and tissues with high fidelity. Recent studies have identified valid isotopic measures of short- and long-term sugar intake, meat intake, and fish intake in specific populations. These studies provide a strong foundation for validating stable isotopic biomarkers in the general US population. Approaches to improve specificity for specific foods are needed; for example, by modeling intake using multiple stable isotope ratios or by isolating and measuring specific molecules linked to foods of interest. Expected final online publication date for the Annual Review of Nutrition Volume 35 is July 17, 2015. Please see http://www.annualreviews.org/catalog/pubdates.aspx for revised estimates.
Article
The objective of this study is to test the feasibility of multi- isotopic and elemental analyses combined with chemometric techniques for differentiating the botanical origins of major honey products in China. The stable isotope and elemental compositions of 57 honey samples from four major floral origins in China (i.e. rape honey, acacia honey, vitex honey and jujube honey) were analyzed using stable isotope ratio mass spectrometry(IRMS)and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The results showed that hydrogen and oxygen isotopes could be more suitable than carbon isotope for discriminating the floral origins of major honey in China. There were significant differences in the contents of most elements between or among different floral origins. The combination of IRMS and ICP-MS methods provides the most effective and accurate approach (in most cases close to 100% accuracy) for classifying Chinese honey according to their floral origins.
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Rationale In recent years, segmental stable isotope analysis of hair has been a focus of research in animal dietary ecology and migration. To correctly assign tail hair segments to seasons or even Julian dates, information on tail hair growth rates is a key parameter, but is lacking for most species. Methods We (a) reviewed the literature on tail hair growth rates in mammals; b) made own measurements of three captive equid species; (c) measured δ2H, δ13C and δ15N values in sequentially cut tail hairs of three sympatric, free-ranging equids from the Mongolian Gobi, using isotope ratio mass spectrometry (IRMS); and (d) collected environmental background data on seasonal variation by measuring δ2H values in precipitation by IRMS and by compiling pasture productivity measured by remote sensing via the normalized difference vegetation index (NDVI). Results Tail hair growth rates showed significant inter- and intra-specific variation making temporal alignment problematic. In the Mongolian Gobi, high seasonal variation of δ2H values in precipitation results in winter lows and summer highs of δ2H values of available water sources. In water-dependent equids, this seasonality is reflected in the isotope signatures of sequentially cut tails hairs. Conclusions In regions which are subject to strong seasonal patterns we suggest identifying key isotopes which show strong seasonal variation in the environment and can be expected to be reflected in the animal tissue. The known interval between the maxima and minima of these isotope values can then be used to correctly temporally align the segmental stable isotope signature for each individual animal.
Article
Gum Arabic (GA) is a popular wine additive. Due to its compositional and structural similarity to native grape cell wall arabinogalactans occurring in wine, the chemical proof of a GA addition is difficult. A method for its identification based on the colloid composition and multi-element (H, O and N, C) stable isotope analysis of the colloids was developed. For this purpose, the colloids from non-spiked, authentic (control) and spiked (300 mg l−1 GA) German white wines were isolated and analyzed for their monosaccharide composition. An addition of 300 mg l−1 GA changed the monomer sugar composition of the colloids. Particularly, l-arabinose, d-galactose, d-mannose and d-glucuronic acid were affected. Additionally, the oxygen stable isotope ratios of the isolated polysaccharides were shifted. Principle component analysis indicated the grouping of treated and untreated samples with 300 mg l−1 GA. The groupings were influenced by the content of l-arabinose and d-galactose, colloid content, monosaccharide content, monosaccharide composition and the δ18O values. It could also be concluded that a high content of l-arabinose and d-galactose was accompanied with a lower content of d-mannose. The control samples were only influenced by a significantly higher d-mannose content.
Article
Traditionally, the oxygen 18 stable isotope measurement of water using a CO2 equilibration system is performed on a liquid solution that could be a limitation for various applications. This paper demonstrates that δ18O measurements of in situ water contained in pasty matrices (dried fruits) can be performed directly on a matrix without previous water extraction using a commercial system of isotope ratio mass spectrometry (IRMS) under similar equilibration conditions used for liquids (6 h at 40 °C). The main difference is that instead of pouring a liquid in the equilibration vial, a pasty matrix is spread on the vial walls using a spatula. Water standard analysis is used for equilibration gas calibration. The increase in the amount of pasty matrix in the vial leads to an increase in δ18O values, until a plateau is obtained, indicating the optimum sample mass that is found to be 200 mg for a paste containing 35% of humidity. The results are obtained with a repeatability of 0.27‰. A set of 37 prunes is used to illustrate the method application for the discrimination between 2 different kinds of products: the δ18O value allows a clear discrimination between the prunes re-hydrated (δ18OVSMOW range: −0.78 to +3.77‰) and non-re-hydrated (δ18OVSMOW range: +8.97 to 14.86‰).
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The application of stable isotope analysis has provided novel approaches for provenancing unidentified human remains from forensic contexts. Stable isotope ratios measured in human tissues provide a record of the foods consumed during life as well as the geographic location where drinking water or food was obtained. This study begins with an overview of the application of stable isotope analysis for provenancing human remains, followed by three cases that illustrate how chemical signatures in bone reflect a probable region of origin. Using stable carbon and nitrogen isotopes of human bone, we test whether human skeletal remains recovered by the Joint POW/MIA Accounting Command-Central Identification Laboratory (JPAC-CIL, or CIL) reflect a geographic origin within North America or Asia. Stable carbon and nitrogen isotopes of human bone collagen and stable carbon isotopes of bone apatite reflect consumption of food resources that are expected to vary between world regions due to cultural dietary differences. Based on the isotopic differences, a testable hypothesis of geographic origin can be applied, determining if the remains are more likely of a U.S. service person or of an indigenous local. We believe that this approach can provide useful information for narrowing search parameters in unidentified persons cases; can contribute to human rights cases where an unknown individual is thought to originate from a different geographic area; and, in human remains cases of unknown geographic provenience, can determine whether a person is local or nonlocal.
Article
RATIONALE: Measurement of δ2H values in non-exchangeable-H (δ2Hn) and δ18O values in organic environmental samples are inconsistent among laboratories worldwide due to varied and lengthy approaches in controlling for H isotope exchange (for δ2Hn values) and removal of trace moisture (δ2Hn and δ18O values), which undermines the comparability of organic δ2H and δ18O data produced among different laboratories. METHODS: An online preparation system was developed for the measurement of the δ2Hn and δ18O values of organic samples, coupled to isotope-ratio mass spectrometers. The system features a 50-position autosampler and isolation valve where (1) the samples are held isothermal between ambient to 40–120 ± 0.1 °C for H isotopic exchange experiments (δ2Hn) and drying of hygroscopic samples (δ2Hn and δ18O), (2) the samples are evacuated to <5 mbar and flushed with helium for moisture and N2 removal, and (3) injection of up to 500 μL of H2O is possible for controlled vapour exchangeable-H experiments. RESULTS: The system provides highly reproducible and precise δ2Hn isotope estimates for a range of organic keratinous standard powders over a wide range of experimental temperatures. A reproducible sample processing regimen can now be applied to a wider range of organics and hygroscopic samples that are currently hampered by poorly controlled preparative methods amongst laboratories. CONCLUSIONS: Rapid and reproducible online vacuum equilibration of samples and standards for the routine measurement of δ2Hn and δ18O values is now possible using the online equilibration system, with the added benefit that sample processing times for organic δ2H values are reduced from weeks to hours.
Article
This paper reviews a body of work published by the authors over a number of years aimed at providing a complementary “signature” to conventional chemical profiling of methylamphetamine. The work, beginning in 2009, was undertaken because of the changing nature of clandestine methylamphetamine manufacture which has seen a dramatic rise in production and a major shift to a higher quality product. As manufacturing methods changed and methylamphetamine purity increased some conventional drug profiling techniques became less useful as an intelligence tool. For instance, the value of the organic impurity profile, a mainstay of conventional profiling, decreases as there are fewer impurities present in seized samples. However, whilst many seizures may contain less conventional chemical intelligence another property of the methylamphetamine molecule is always available, i.e. the light element stable isotope ratios. The stable isotope ratios of carbon, hydrogen and nitrogen are an integral part of the methylamphetamine molecule itself. This review describes previous work by the authors and by researchers in other national laboratories to investigate and implement the use of stable isotope ratios as an everyday methylamphetamine profiling tool. It also looks at how powerful this technique can be when used to compare samples from different seizures.
Article
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The use of mass spectrometry to analyse the stable-isotope ratios of bird tissues has become an important new tool for research ornithologists in the last 20 years. Because stable isotopes vary geographically and according to specific biological processes in the environment, they provide a unique forensic means of understanding more about avian biology and ecology than we can learn using conventional techniques alone. The stable-isotope ratios present in different tissues of birds reflect the ratios in the environment at the time those tissues were constructed. However, because of the rapid turnover of some tissues compared with others, an individual bird will bear within its body constituents a record of its present and past exposure to different isotopic environments. Because the stable-isotope ratios of specific elements vary geographically (e.g. hydrogen along oceanic to continental gradients) and between habitats (e.g. nitrogen and carbon in marine versus terrestrial ecosystems), they offer a unique means of studying the ways migratory birds move between different parts of the planet and of understanding the habitats they exploit. This review looks at some of the innovative ways in which the technique has been used in a variety of recent studies of birds. The technique is not restricted to breaking new ground in high science; in terms of understanding migration strategies, the importance of breeding, migratory and wintering habitat and the feeding ecology of birds, the study of stable-isotope ratios is becoming ever more important in supporting conservation actions.
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Studies performed during the last two decades have shown that lipids are preserved in association with a wide range of artefact and ecofacts recovered from archaeological sites, e.g. pottery vessels and skeletal remains. The majority of work in thi area has focused on the use of molecular structures (‘biomarkers’) and distributions (‘fingerprints’) to assess the natur and origin of commodities associated with past cultural, economic and agricultural practices. However, since lipids, lik all other classes of biomolecule, are affected by degradation (both pre– and post–burial), emphasis is now being placed o the complementary use of diagenetically robust, compound–specific stable isotope measurements to enhance the scope and reliabilit of archaeological interpretations. A feature of the δ13C values of individual lipids, rather than bulk measurements of biochemically more heterogeneous materials, lies in thei capacity to reflect differences in both the isotopic composition of the carbon sources used in their biosynthesis and th routing of dietary lipids and their metabolites in consumer organisms. This isotopic information, accessible by gas chromatography–combustion–isotop ratio mass spectrometry, has opened up new avenues of investigation concerning human activity in prehistory.
Article
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Stable carbon isotopes in the bone collagen of prehistoric humans are valuable tools for determining human diet. We studied carbon isotopes in individual amino acids (IAA) in plants and collagen from herbivores and humans from North American prehistoric sites in order to determine whether more specific dietary information about Indians could be predicted. The δ13C of plant amino acids ranged extensively, whereas δ13C values of each amino acid from the C3(n=3) and C4(n=3) plant species were linearly related with a slope of 0.8. Essential amino acids from herbivores had δ13C values that were completely different from those measured in either C3or C4plants, suggesting metabolic resynthesis in the gut by microflora. The δ13C of essential amino acids from prehistoric North Americans, who had diets ranging from primarily maize-based (C4) to hunter-gathers (C3) subsistence, were highly correlated with δ13C values of herbivore essential amino acids. There was no significant correlation of δ13C in IAA from humans with those of plants. The δ13C of nonessential amino acids in human bone collagen can distinguish the presence of maize in the diet, whereas the δ13C of essential amino acids were transparent to a maize-derived carbon signal. Compound specific isotopic data on IAA distinguish between total carbon intake versus total protein intake and are useful for discerning the extent and nature of omnivory.
Article
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High precision isotope ratio mass spectrometry (IRMS) enables the detection of variability in isotope abundance due to natural processes. IRMS instruments are highly specialized for the analysis of 13 C / 12 C, 2 H / 1 H, 15 N / 14 N, 18 O / 16 O, and 34 S / 32 S via analysis gases CO 2, H 2, N 2, and SO 2 using a tight electron impact ion source, high transmission magnetic sector, and multiple collectors, delivering relative standard deviations of less than 0.01%. Recent developments exploiting continuous flow inlets have improved sample throughput and permitted a wide range of samples to be analyzed by highly automated systems. Isotope ratio analysis at the bulk mixture and compound-specific levels is now routine, and strategies for intramolecular analysis are on the horizon. Studies over 50 years have shown that isotopic fractionation due to physiological processes, specifically CO 2 transport processes within plants and photosynthesis, leads to variation in isotope ratio in natural compounds. Different chemical processes leading to isotope fractionation operate in the generation of petroleum. IRMS analysis can, in many cases, distinguish petroleum derived from different geographical regions that are otherwise identical. In wines and juices, climate differences that depend on geographic location induce isotopic fractionation that can be detected by IRMS and are characteristic of region and even vintage. Intramolecular or chiral isotope analysis is able to detect the origin of flavor compounds such as vanillin. Use of illicit, endogenous drugs such as testosterone, can be detected by isotope ratio analysis when referenced against another endogenous steroid upstream or independent of the endogenous biosynthetic pathway. These and related applications show that natural isotopic structure is a powerful tool for determining the origin of organic compounds.
Book
Stable isotope ratio variation in natural systems reflects the dynamics of Earth systems processes and imparts isotope labels to Earth materials. Carbon isotope ratios of atmospheric CO2 record exchange of carbon between the biosphere and the atmosphere; the incredible journeys of migrating monarchs is documented by hydrogen isotopes in their wings; and water carries an isotopic record of its source and history as it traverses the atmosphere and land surface. Through these and many other examples, improved understanding of spatio-temporal isotopic variation in Earth systems is leading to innovative new approaches to scientific problem-solving. This volume provides a comprehensive overview of the theory, methods, and applications that are enabling new disciplinary and cross-disciplinary advances through the study of "isoscapes": isotopic landscapes. "This impressive new volume shows scientists deciphering and using the natural isotope landscapes that subtly adorn our spaceship Earth." Brian Fry, Coastal Ecology Institute, Louisiana State University, USA "An excellent timely must read and must-have reference book for anybody interested or engaged in applying stable isotope signatures to questions in e.g. Anthropology, Biogeochemistry, Ecology, or Forensic Science regarding chronological and spatial movement, changes, or distribution relating to animals, humans, plants, or water." Wolfram Meier-Augenstein, Centre for Anatomy & Human Identification, University of Dundee, UK "Natural resources are being affected by global change, but exactly where, how, and at what pace? Isoscapes provide new and remarkably precise answers." John Hayes, Woods Hole Oceanographic Institution, USA "This exciting volume is shaping a new landscape in environmental sciences that is utilizing the remarkable advances in isotope research to enhance and extend the capabilities of the field." Dan Yakir, Weizmann Institute of Science, Israel.
Book
Soils have important roles to play in criminal and environmental forensic science. Since the initial concept of using soil in forensic investigations was mooted by Conan Doyle in his Sherlock Holmes stories prior to real-world applications, this branch of forensic science has become increasingly sophisticated and broad. New techniques in chemical, physical, biological, ecological and spatial analysis, coupled with informatics, are being applied to reducing areas of search by investigators, site identification, site comparison and measurement for the eventual use as evidence in court. Soils can provide intelligence, in assisting the determination of the provenance of samples from artifacts, victims or suspects, enabling their linkage to locations or other evidence. They also modulate change in surface or buried cadavers and hence affect the ability to estimate post-mortem or post-burial intervals, and locate clandestine graves. This interdisciplinary volume explores the conceptual and practical interplay of soil and geoforensics across the scientific, investigative and legal fields. Supported by reviews, case-studies from across the world, and reports of original research, it demonstrates the increasing convergence of a wide range of knowledge. It covers conceptual issues, evidence (from recovery to use in court), geoforensics, taphonomy, as well as leading-edge technologies. The application of the resultant soil forensics toolbox is leading to significant advances in improving crime detection, and environmental and national security.
Article
The applicability of isotopic analysis of 13C for forensic purposes has been discussed in the case of heroin. The obtained results showed first that morphine acetylation induces an isotopic fractionation, so that the 13C enrichment of diacetylmorphine depends on both geographical origin of the sample and source of acetic anhydride used by the drug trafficker. That measurement can then be of great interest in the determination of common- batch samples (tactical intelligence purpose). Second, diacetylmorphine deacetylation has also been studied and it appeared that this deacetylation allows to relieve the enrichment from the acetylation-induced part. Therefore, measuring morphine 13C enrichment, from deacetylated heroin samples, can be useful for determining the geographical origin of the samples (strategic intelligence purpose). Moreover, measuring both diacetylmorphine and morphine 13C enrichments may help identify the source of acetic anhydride used by the drug trafficker, so that the fraudulent laboratory where the morphine samples have been acetylated.
Article
The extensive studies on plant metabolism and natural fractionation of stable isotopes enabled access to an extremely useful tool in the fight against fraud in the food products domain. Several isotopic analyses are now official or standard methods in Europe and North America for testing the authenticity of food products. These methods are based on the measurement of stable isotope contents (2H, 13C, 18O, 15N, etc.) of a product or of a specific component such as an ingredient or a target molecule of the product. The determinations, carried out using NMR (nuclear magnetic resonance) and/or IRMS (isotope ratio mass spectrometry), provide information on the botanical and geographical origin which are often considered important characteristics of many food products either by the consumer or by European regulations.
Chapter
Scale and spatial resolutionSampling for geological materials at urban and non-urban crime scenesTiming of the crimeSample sizeLateral variationUse and misuse of statistics in forensic studiesStatistical samplingNumber of samples required for robust statistical analysisComparing ‘like with like’Addressing the issue of comparing related materialSpatial and temporal variability in natureSpatial awareness and use of spatial statistics: application of geostatisticsGeostatistical techniquesGIS and geostatistics
Article
The correlations between isotope ratios in water, organic mass, and trace elements of food and beverages, and the circumstances and sites of their origin and production are outlined, and the methods of mass spectrometric isotope ratio determination and the positional H-2 analysis by quantitative NMR measurement are explained. In context with the application of these methods for origin and authenticity investigations of food, examples are given for the proof of watering or sugar addition to wine and fruit juices and methods for the identification of nondeclared additions of L-malic and L-ascorbic acids are described, The possibilities of multielement isotope ratio analysis for the identification of origin of animal products (eggs, milk products, meat) and methods for the discriminations between natural and nature identical aroma compounds are outlined. Finally, the possibilities of isotope ratio measurements for the discrimination between plant and animal food from conventional and organic production are discussed.
Article
The use of biomarkers in combination with stable isotope analysis is a new approach in microbial ecology and a number of papers on a variety of subjects have appeared. We will first discuss the techniques for analysing stable isotopes in biomarkers, primarily gas chromatography-combustion-isotope ratio mass spectrometry, and then describe a number of applications in microbial ecology based on 13C. Natural abundance isotope ratios of biomarkers can be used to study organic matter sources utilised by microorganisms in complex ecosystems and for identifying specific groups of bacteria like methanotrophs. Addition of labelled substrates in combination with biomarker analysis enables direct identification of microbes involved in specific processes and also allows for the incorporation of bacteria into food web studies. We believe that the full potential of the technique in microbial ecology has just started to be exploited. © 2002 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.
Article
Over the last half century, the science and practice of forensic science has undergone dramatic changes. Since the early 1960s the technological developments and their application to forensic science have been immense. Not only that, the application of science within a legal context and framework has developed enormously, as has the evaluation of the analytical results obtained. This unique text looks at the changes and challenges within forensic science over the last fifty years through a continuous diary of development witnessed by the editorials and relevant correspondence delivered through the UK Forensic Science Societies' journal Science and Justice (formally the Journal of the Forensic Science Society). The editorials are divided into sections relating to the developments of forensic practice, the advancement of science, education, legal aspects, forensic science and medicine, the international dimension of forensic science and the interpretation and evaluation of evidence. The text and first two sections are set in context by an introductory chapter written by Professor Brian Caddy examining the future of forensic science. A key text that traces the historical development of forensic science through reflective editorials published in the journalScience and Justice, and theJournal of the ForensicScience Society. Includes introductory chapter by Professor Brian Caddy. Divided into themed sections to reflect current commentary and debate.
Article
The NanoSIMS (Cameca 'NanoSIMS 50' ion microprobe) is a new type of ion microprobe that can be used for elemental and isotopic studies on a sub-micrometer scale. The instrument is based on a design concept by G. Slodzian (Université de Paris-Sud) who was also responsible for the development of the very successful CAMECA ims3f-7f series, as well as the ims1270/1280. The NanoSIMS 50 was built by CAMECA in France and the first instrument of this type was delivered to Washington University in St. Louis (MO, USA) in December 2000. By now there are more than ten NanoSIMS instruments installed world-wide with applications ranging from cosmochemistry to biology and material sciences. The most significant innovation in the ion optical design of the NanoSIMS (Figure 12-0.6) is the normal primary ion incidence and a normal coaxial secondary ion extraction. This makes it possible to reduce the distance between the sample and the immer-sion lens to 400 mm, which results in a much smaller spot size than in other SIMS instruments at a given probe current. The diameter of the primary ion beam at the sample defines the smallest area whose chemical or isotopic composition can be determined without interference from neighboring regions. Obviously, a smaller spot size allows the analysis of smaller particles and gives more detailed information about the internal composition of a given sample of heterogeneous composition. In imaging mode, the primary beam diameter defines the lateral resolution of a secondary ion image. The typical Cs þ primary beam diameter of a CAMECA f-series ion microprobe is on the order of 1–3 mm although slightly smaller spot sizes can be achieved through careful tune-up and with significant loss of intensity. The NanoSIMS, in contrast, offers a routine Cs þ primary beam diameter of 100 nm (hence the instrument's name), but beam diameters as low as 30 nm have been achieved. In negative (O À) primary beam mode the best achievable probe diameter is around 150 nm.
Article
For planktophytes, an increase in size above c50 mu m diameter would restrict growth rate in oligotrophic environments owing to a greater increment of restriction by boundary layer of nutrient uptake than of maximum specific growth rate as organism size increases. For macroscopic aquatic haptophytes (mainly algae), even the most favourable combination of velocity of water flow and plant morphology cannot reduce these restrictions enough to make nutrient diffusion to the plant surface less limiting for growth in oligotrophic environments than is the case for planktophytes. Macroscopic aquatic rhizophytes, with their need for intraplant N- and P-flux from rhizoid or root to shoot, and for reduced C-flux from shoot to rhizoid or root, involves cytoplasmic streaming in giant-celled algae, and transport in the phloem and (probably) the xylem. The predominant (in terms of global biomass) terrestrial plants are the rhizophytic, homoiohydric desiccation-intolerant sporophytes of vascular plants. These incur greater penalties, in terms of reduced specific growth rate under resource-saturated or resource-limited conditions, and of reduced resource use efficiency, with increased plant height, a result of diversion of resources to producing supporting tissue, and xylem and phloem in larger amounts per unit biomass than is the case for smaller plants. But through increased size a plant can command a higher incident photon flux density as well as access to a greater depth of soil from which nutrients and water can be extracted. Other major categories of terrestrial rhizophytes are desiccation-tolerant homoiohydric sporophytes of vascular plants, endohydric but poikilohydric gametophytes of mosses, and ectohydric gametophytes of archegoniates and thalli of many algae and lichens. -from Authors
Book
This title brings forensic scientists and chemists up-to-date on the latest instrumental methods for analysing trace evidence, including mass spectrometry, image analysis, DIOS-MS, ELISA characterization, statistical validation, and others. Illustrates comparative analysis of trace evidence by both old and new methods. Explains why some newer methods are superior to older, established methods. Includes chapters on analysis of DNA, ink, dyes, glitter, gun powder traces, condom trace evidence, footwear impressions, toolmark impressions, surveillance videos, glass particles, and dirt. Discusses applications such as mass spectrometry, image analysis, desorption-ionization on silicon mass spectrometry (DIOS-MS), ELISA characterization, and statistical validation.
Article
The oxygen isotope compositions of three wood constituents (the solvent-extractable portion, lignin and α-cellulose) were measured for samples collected from Quercus and Pinus trees around the world. Among Pinus samples all wood constituents were positively related to modelled δ18O of source water at the site, while among Quercus samples whole wood, lignin and α-cellulose showed positive relationships. The data support the hypothesis that many oxygen atoms in lignin exchanged with unenriched stem water during synthesis, rather than retaining the full isotopic signal from the molecular oxygen added during hydroxylation of the aromatic ring. The data also suggest that extraction of α-cellulose from wood samples is unnecessary for isotope studies looking at correlations with site parameters.
Article
An evaluation was undertaken to determine if isotope ratio mass spectrometry (IRMS) could assist in the investigation of complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. The focus of the research was on ammonium nitrate (AN), a common oxidiser used in improvised explosive mixtures. The potential value of IRMS to attribute Australian AN samples to the manufacturing source was demonstrated through the development of a preliminary AN classification scheme based on nitrogen isotopes. Although the discrimination utilising nitrogen isotopes alone was limited and only relevant to samples from the three Australian manufacturers during the evaluated time period, the classification scheme has potential as an investigative aid. Combining oxygen and hydrogen stable isotope values permitted the differentiation of AN prills from three different Australian manufacturers. Samples from five different overseas sources could be differentiated utilising a combination of the nitrogen, oxygen and hydrogen isotope values. Limited differentiation between Australian and overseas prills was achieved for the samples analysed. The comparison of nitrogen isotope values from intact AN prill samples with those from post-blast AN prill residues highlighted that the nitrogen isotopic composition of the prills was not maintained post-blast; hence, limiting the technique to analysis of un-reacted explosive material.
Article
The application of isotopic techniques to investigations requiring the provision of evidence to a Court is limited. The objective of this research was to investigate the application of light stable isotopes and isotope ratio mass spectrometry (IRMS) to solve complex forensic cases by providing a level of discrimination not achievable utilising traditional forensic techniques. Due to the current threat of organic peroxide explosives, such as triacetone triperoxide (TATP), research was undertaken to determine the potential of IRMS to differentiate samples of TATP that had been manufactured utilising different starting materials and/or manufacturing processes. In addition, due to the prevalence of pentaerythritoltetranitrate (PETN) in detonators, detonating cord, and boosters, the potential of the IRMS technique to differentiate PETN samples from different sources was also investigated. Carbon isotope values were measured in fourteen TATP samples, with three definite groups appearing in the initial sample set based on the carbon data alone. Four additional TATP samples (in a second set of samples) were distinguishable utilising the carbon and hydrogen isotopic compositions individually, and also in combination with the oxygen isotope values. The 3D plot of the carbon, oxygen and hydrogen data demonstrated the clear discrimination of the four samples of TATP. The carbon and nitrogen isotope values measured from fifteen PETN samples, allowed samples from different sources to be readily discriminated. This paper demonstrates the successful application of IRMS to the analysis of explosives of forensic interest to assist in discriminating samples from different sources. This research represents a preliminary evaluation of the IRMS technique for the measurement of stable isotope values in TATP and PETN samples, and supports the dedication of resources for a full evaluation of this application in order to achieve Court reportable IRMS results.
Book
The amount of information forensic scientists are able to offer is ever increasing, owing to vast developments in science and technology. Consequently, the complexity of evidence does not allow scientists to cope adequately with the problems it causes, or to make the required inferences. Probability theory, implemented through graphical methods, specifically Bayesian networks, offers a powerful tool to deal with this complexity, and discover valid patterns in data. Bayesian Networks and Probabilistic Inference in Forensic Science provides a unique and comprehensive introduction to the use of Bayesian networks for the evaluation of scientific evidence in forensic science. Includes self-contained introductions to both Bayesian networks and probability. Features implementation of the methodology using HUGIN, the leading Bayesian networks software. Presents basic standard networks that can be implemented in commercially and academically available software packages, and that form the core models necessary for the reader's own analysis of real cases. Provides a technique for structuring problems and organizing uncertain data based on methods and principles of scientific reasoning. Contains a method for constructing coherent and defensible arguments for the analysis and evaluation of forensic evidence. Written in a lucid style, suitable for forensic scientists with minimal mathematical background. Includes a foreword by David Schum. The clear and accessible style makes this book ideal for all forensic scientists and applied statisticians working in evidence evaluation, as well as graduate students in these areas. It will also appeal to scientists, lawyers and other professionals interested in the evaluation of forensic evidence and/or Bayesian networks.
Article
Profile analysis of impurities associated with heroin samples and 13C enrichment of heroin are studied in attempts to trace the origin of heroin samples in drug abuse. High-resolution capillary gas chromatography (GC) and mass spectrometry (MS) allow comparative evaluation of various samples with reference to relative retention times, mass spectra and GC peak area. A program developed on a HP 59970 work-station is described for calculating the relative retention time of each integrated GC peak with reference to added standards (p, p′-DDT and triacontane) or normally present in samples (meconine); these data are then treated statistically for comparison of samples. When GC is combined with isotope-ratio MS, 13C enrichment can be measured at natural abundance level. Preliminary results show some evidence of variation of 13C enrichment according to the geographical site of production.
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Publisher Summary This chapter discusses the present limits to interpretation for uncultivated systems with original data from Scottish old fields in reference to terrestrial plant ecology and I5 N natural abundance. The use of I5 N natural abundance (δ 15 N) is a powerful tool for obtaining insights through δ I5 N pattern analysis, and for deriving new questions to be tested, but it is not a reliable tracer of nitrogen fluxes in soils or in plants growing in soils. To interpret δ 15 N in terms of sources and sinks, one must know the source δ 15 N values, be able to quantify the fractionations occurring between source and sink, and frequently be able to estimate nitrogen fluxes. Given the widespread absence of such knowledge, question arises whether much of the published literature on δ 15 N for terrestrial systems can have been interpreted correctly. Moreover, the techniques of δ 15 N analyses are ideally suited to research in remote locations but not the interpretations. Nitrogen isotope interpretations are complicated and depend on a thorough knowledge of the site under study and on controlled experimentation. The isotopic values do not, themselves, supply the answers. The answers are supplied through examining patterns of isotopic signatures in the context of what is already known about the system's ecology and through testing hypotheses which arise from analysis of the δ 15 N patterns.
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Stable isotopic analysis--particularly compound specific stable carbon isotopic analysis--is being increasingly investigated and applied as a tool to investigate and monitor the sources and fates of contaminant compounds in the environment. Results of an increasing number of studies indicate that stable isotopic analysis is a promising tool in environmental chemistry. This paper discusses reported results and presents a case study of stable carbon isotopic analysis of volatile organic groundwater contaminants to illustrate the present abilities and limitations of the application of stable isotopic analysis to environmental contaminants. Though this paper focuses on stable carbon isotopic analysis of volatile organic compounds, the principles discussed herein are relevant to all applications of isotopic analysis as an environmental forensic tool.
Article
Characterization and identification of explosives and explosive residues collected from different places in India were made using TLC, GC/EI-MS, and GC-FTIR. The explosives used were NG, PETN, TNT, tetryl, RDX, and NH4NO3+fuel oil. Quantitative estimation was made using HPTLC. Mass spectra of the samples using selective ion monitoring (SIM) mode based on the relative intensities of the signals X, X + 1 (intensity of the largest fragment X of the explosive, say, RDX [X = 205] was assumed to be 100%, i.e., X = 100%) show no isotopic substitution. The results were confirmed by FTIR spectra. Some physico-chemical aspects of the explosives are discussed.
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This paper presents a comparison of the isotopic values of 23 pairings of hair keratin and bone collagen taken from archaeological humans excavated in the U.K. with the aim of examining whether modern human isotopic data can be directly compared with archaeological isotopic data. The mean differences between bone collagen and hair keratin isotopic values are in the range of 0–1 per mil in δ13C and 0–2 per mil in δ15N, but with a high degree of variability, making it impossible to quantify the isotopic relationship between collagen and keratin. However, a lack of information about the individuals analysed suggests that such a comparison may not be the ideal method of comparing the two tissues.
Article
12C13C natural isotopic abundances have been measured in a randomly chosen set of confiscated 3,4-(methylenedioxy)methylamphetamine (MDMA, XTC, Ecstacy) tablets using online gas chromatography isotope ratio mass spectrometry. The high precision obtained with this method allowed the discrimination of at least four different groups of MDMA tablets according to variations in their natural 13C12C isotopic ratio. It is shown that further discrimination can be obtained by using the 15N14N isotopic ratios in MDMA.
Article
An analytical method to determine trace element concentrations and their ratios in the glue of brown PSA packaging tapes is described. The method relies on acid digestion in quartz vessels inside a closed microwave unit and measurement by sector field ICP-MS. This methodology was applied to nine tape rolls purchased from three different shops of three different chain stores. It was possible to discriminate both between brands and within brand for all three brands. In the case of one brand, for rolls originating from the same product line but from different production batches, it was shown that the ‘between batch’ difference is detectable whilst there is no statistically significant difference within rolls from the same production batch. This combination of ‘between batch’ differences and ‘within batch’ consistency may provide the forensic scientist with the means to discriminate between tape rolls even if they come from the same product line.
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A review is presented, covering literature published up to October 1998. The continuing interest in in vivo measurements of Pb in bone by XRF and tissue solubilization, and increased use of high resolution ICP MS are discussed. An increased interest in Al metabolism and the use of Monte Carlo systems are also reported. (593 references).
Article
Observed variations in the δ13C and δ15N content of amphetamines are shown to be attributable to kinetic isotope effects during synthesis; chemical degradation and isotopic characterisation provides a means to identify the synthetic origins of illicit MDMA and other amphetamines.
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An examination of the practice of derivatizing organic compounds such as fatty acids, sterols and amino acids in relation to subsequent analysis via gas chromatography-combustion-isotope ratio mass spectrometry is presented. Fractionation processes, such as kinetic isotope effects, which cause a deviation in the measured stable carbon isotope ratios (delta-values) of derivatized compounds from simple mass balance considerations are examined. Particular attention is paid to reactions that proceed by the cleavage of a carbon-containing bond and reactions that are likely to have kinetic isotope effects associated with them, such as acetylation and diazotization. Isotope fractionation processes other than those which are kinetic based are also discussed, as is the additional imprecision of the calculation of the delta-values of sample compounds inherent when derivative carbon is added. Failure to take this imprecision into account when comparing delta-values could lead to erroneous conclusions with respect to the magnitude of kinetic isotope effects caused by derivative reactions.
Article
The hydrogen stable isotope ratio of organic matter containing hydrogen that is not solely conservative, nonexchangeable, carbon-bound hydrogen depends on sample preparation, because organic hydrogen bound to oxygen and nitrogen may exchange isotopically with ambient-water hydrogen. The method described here permits the determination of the concentration and stable isotopic composition of the nonexchangeable hydrogen in complex organic matter, such as geochemicals and biological and archaeological organic materials. Aliquots of organic substrates were independently equilibrated with water vapors of different hydrogen isotopic compositions, followed by determinations of the bulk D/H ratios. Mass-balance calculations permit eliminating or minimizing the interference of exchangeable hydrogen. The precision of the calculated stable isotope ratio of nonexchangeable hydrogen can be better than +/- 3 per mil, depending on the precision of the measured values for bulk hydrogen. The accuracy of D/H ratios of nonexchangeable hydrogen was improved over that of previously available methods, as shown for cellulose/cellulose nitrate.
Article
Compound-specific isotope analysis (CSIA) of fatty acids is a relatively young analytical method. However, CSIA of fatty acids has increasingly become the method of choice in areas where accurate and precise knowledge of isotopic composition at natural abundance level is important. CSIA of fatty acids at natural abundance level provides information on biogenetic and geographic origin of lipids and oils that is invaluable for research into archaeology and the environment and almost indispensable these days for authenticity control and fraud detection in food analysis. In combination with naturally enriched or stable isotope labelled precursors, CSIA of fatty acids has also gained increasing importance in biochemical, -medical and -geochemical applications as it offers a reliable and risk-free alternative to the use of radioactive tracers.
Article
We present Sr, C and O isotope ratios and quantitative ratios of trace element ratios in the rib and the femur of the Tyrolean Iceman “Ötzi”. The results from the rib and the femur are compared with those obtained from pre-industrial historic human skull bone fragments collected in the late 19th century from charnel houses located on different geological backgrounds throughout North and South Tyrol. Comparison of strontium isotope data from the bone fragments locates the Iceman's domicile, during the last 5 to 10 years of his life, to the crystalline part of the Central Alps. Statistical analysis of the trace element ratios, together with oxygen isotope results, suggests that the Iceman probably spent most of his last years in southern elevated part of the Ötztal. However, the results from Iceman only represent those from a single individual and are not a representative average of a group. It cannot therefore be established with absolute certainty that the original trace element signatures were conserved, especially during the first stage of mummification. Our conclusions should therefore be regarded as tentative, but nevertheless the best possible indication his domicile, and a stimulus for further research.
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This book highlights new and emerging uses of stable isotope analysis in a variety of ecological disciplines. While the use of natural abundance isotopes in ecological research is now relatively standard, new techniques and ways of interpreting patterns are developing rapidly. The second edition of this book provides a thorough, up-to-date examination of these methods of research. As part of the Ecological Methods and Concepts series which provides the latest information on experimental techniques in ecology, this book looks at a wide range of techniques that use natural abundance isotopes to: Follow whole ecosystem element cycling understand processes of soil organic matter formation follow the movement of water in whole watersheds understand the effects of pollution in both terrestrial and aquatic environments study extreme systems such as hydrothermal vents follow migrating organisms. In each case, the book explains the background to the methodology, looks at the underlying principles and assumptions, and outlines the potential limitations and pitfalls. Stable Isotopes in Ecology and Environmental Science is an ideal resource for both ecologists who are new to isotopic analysis, and more experienced isotope ecologists interested in innovative techniques and pioneering new uses.
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Stable (i.e. non-radioactive) carbon-isotope composition (δC) in fuels has been extensively used as an indicator of the processes leading to the generation of their parent crude-oil. With the example of those used in Paris (France), this preliminary study isotopically characterizes fuels and combustibles, as well as the isotopic relations existing with their combustion by-products, i.e. gases (CO2) and particles (bulk carbon). Results show that δC in fuels is clearly related to their physical state, with natural gas being strongly depleted in C while coal yields the highest δC, and liquid fuels display intermediate values. This relation is also valid for combustion gases, although δC values of combustion particles form a homogeneous range within which no clear distinction is observed. Combustion processes are accompanied by carbon-isotope fractionation (noted ΔC) resulting from the combustion being incomplete. Carbon-isotope fractionation is strictly negative (ΔC = −1.3‰) during the formation of combustion gases, but generally positive in particle formation even if values close to zero are observed. Using simple mixing equations for describing the closed system formed by fuel, CO2 and carbonaceous particles, we discuss the carbon budget for spark-ignition (unleaded gasoline) and diesel engines. Stable carbon isotopes corroborate the already-proved superior efficiency of diesel combustion mode compared with spark ignition, as carbon is preferentially transformed into CO2.