[Show abstract][Hide abstract] ABSTRACT: A methodology based on the mineral analysis determination has been developed to identify the origin of dolerite stone outcrops collected to fabricate lithic objects during the Prehistoric period. The method is based on the use of inductively coupled plasma mass spectrometry (ICP-MS) to analyse rare earth elements (REE) and trace elements.
Additionally a no destructive geochemical analysis based on X-ray fluorescence (XRF) was employed for major elements analysis. The aforementioned methodologies were applied to samples from different archaeological fields or natural outcrops located in the Mediterranean area of Spain, between Valencia and Alicante.
Principal component analysis (PCA)was employed to interpret the dolerite geological provenance. These preliminary results show that statistical analysis permits to distinguish stone sample origins according to their REE profile at regional level and that Ti/Fe major element relation perhaps shows just coarse differences between samples collected on the extreme north and south of the studied region. The proposed method could be useful to discriminate the regional origin of lithic objects belonging to dolerite rocks and to interpret the primary material transport and exchange of lithic materials in Valencian Prehistory.
[Show abstract][Hide abstract] ABSTRACT: ArchaeChemis is a service unit belonging to the Solinquiana research group of the Analytical Chemistry Department at the University of Valencia. ArchaeChemist has been designed as a research unit and technology transfer providing it service to other research groups, organizations and institutions in general.
The unit is working in developing new methodological proposals to overcome some scientific problems in different disciplines related to forensic science, archaeology, biology, geology and environmental science.
Forensic science institutions and police authorities collaboration have taken action to asses different criminal issues.
Information about advancement and distribution of face reconstruction programs employed nowadays by Spanish police corps, “Policia Nacional” and “Guardia Civil”, is provided.
8. Specialist Conference of Forensic Artists 2015, Wertheim, Germany; 05/2015
[Show abstract][Hide abstract] ABSTRACT: Abstract
The aim of the present study was to define a methodological strategy for understanding how post- mortem degradation in bones caused by the environment affects different skeletal parts and for selecting better preserved bone samples, employing rare earth elements (REEs) analysis and multivariate statistics. To test our methodological proposal the samples selected belong to adult and young individuals and were obtained from the Late Roman Necropolis of c/Virgen de la Misericordia located in Valencia city centre (Comunidad Valenciana, Spain).
Therefore, a method for the determination of major elements, trace elements and REEs in bone remains has been developed employing Inductively-Coupled Plasma – Optical Emission Spectroscopy (ICP-OES) and ICP- Mass Spectrometry (MS). Bone samples, mainly rib and femur, from seventy-four individuals have been studied. Principal Component Analysis (PCA) was employed to facilitate the interpretation of the taphonomic processes. A multivariate classification model employing Partial Least Squares Discriminant Analysis (PLSDA) was used to identify bones with less soil contamination. These preliminary results show that statistical analysis can help to classify different bones according to their elemental profile at intraskeletal levels smoothing the way for the identification of better preserved samples. Zn/Ca and Sr/Ca parameters show that diet profiles of a population could change depending on the type of bones analyzed. The proposed method could be useful in forensic science investigations to select better preserved samples in different scenarios.
[Show abstract][Hide abstract] ABSTRACT: In many cases a previous impact on the structure and chemical composition of the bones is induced by cremation during funerary rituals, accident and other human activities. In this study, we have created a statistical classification of carbonized and cremated bones, as well as bones exposed to unknown thermal conditions to identify the degree of burning and to control the impact of diagenesis throughout chemical element analysis. Major elements, trace elements and Rare Earth Elements (REEs,lanthanides) in cremations have been determinate employing ICP-OES. Samples from the inner part of their bones have been divided into “carbonized” indicating bones fired in reducing atmosphere, “cremated” for bones fired in oxidizing atmosphere and “unknown” for bones of unidentifiable burning. Furthermore, bone samples from the outer bone layer, unburned bones and soil samples have been analyzed. PCA have showed that bone samples obtained from the outer bone layer had a different elemental composition more similar to soil than samples of the inner bone layer. PLS-DA results obtained in this study have confirmed that changes in thermal conditions are associated to chemical transformations in the mineral part of the bones. When the thermal conditions in burned bones are uncertain or burned bones are environmentally contaminated, statistical tests may help to assess the condition of cremations according to the elemental profile of samples. The proposed method could be useful in forensic science investigations to select better preserved samples in different scenarios.
3th International Conference on Forensic Research and Technology, San Antonio USA; 10/2014
[Show abstract][Hide abstract] ABSTRACT: A comprehensive strategy for the analysis of current airborne pesticides has been developed using liquid chromatography coupled to high resolution mass spectrometry. The methodology includes both quantitative target analysis and post-run target screening analysis. The quantitative method was validated after a previous statistical optimisation of the main factors governing the ion source ionization and a study of the single-stage Orbitrap fragmentation through the HCD cell. The quantitative method presented recoveries ranging from 73 to 116%, with precision (RSD) lower than 20%, for the 35 substances in the scope of the target method. The full-scan accurate mass data were acquired with a resolving power of 50000 FWHM (scan speed, 2Hz), and alternating two acquisition events, ESI+ without fragmentation and ESI+ with fragmentation. The method-LOQ was 6.5pgm(-3) for most of the target pesticides. For post-target screening a customized theoretical database, that included pesticides, metabolites and other substances such as emerging flame retardants was built up. For identification, accurate exact mass with less than 5ppm, and some diagnostic ions including isotopes and/or fragments were used. The strategy was applied to ten samples collected in a rural area of Valencia (Spain). Four pesticides, namely carbendazim, metalaxyl, myclobutanil and terbuthylazine, were detected in concentrations from 16pgm(-3) to 174pgm(-3). Some pesticides and metabolites (endothal, fenfuram, terbuthylazine-2-OH), in addition to two flame retardants were tentatively identified in the post-run target screening analysis.
Journal of Chromatography A 10/2014; 1368. DOI:10.1016/j.chroma.2014.09.067 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Difficulties to differentiate between anthropogenic and natural processes in the formation of archaeological deposits are crucial for a correct interpretation not only of the actions involved in the development of archaeological sites, but also of their occupationabandonment dynamics and the understanding of their spatial behaviors and relationship with the environment.We have carried out lanthanides (rare earth elements “REE”) analysis to distinguish anthropogenic from natural stratigraphic units in sediments
using the advantage of the high sensibility, precision, and accuracy of ICP-MS measurements. In the Neolithic site of Mas d’Is (Alacant, Spain), we have applied REE analysis in a huge stratigraphic sequence called Pit 6, which was known to contain a large anthropogenic component. Randomly collected soil samples were sequentially taken in order to identify anthropogenic soil formations and to prove the proposed method blind testing has been used. In the specific case of Mas d’Is excavation a recurring
question is whether paleosols are at the origin of the human occupation of the sites or it was the occupation of this areas which triggered the paleosols development. Our purpose was to distinguish the degree of human contribution to paleosols formation between samples sequentially taken at few centimeters of distances in a giant stratigraphic sequence (Pit 6) employing REE analysis.
[Show abstract][Hide abstract] ABSTRACT: Difficulties to differentiate between anthropogenic and natural processes in the formation of archaeological deposits are crucial for a correct interpretation not only of the actions involved in the development of archaeological sites, but also of their occupation-abandonment dynamics and the understanding of their spatial behaviors and relationship with the environment. We have carried out lanthanides (rare earth elements “REE”) analysis to distinguish anthropogenic from natural stratigraphic units in sediments using the advantage of the high sensibility, precision, and accuracy of ICP-MS measurements. In the Neolithic site of Mas d’Is (Alacant, Spain), we have applied REE analysis in a huge stratigraphic sequence called Pit 6, which was known to contain a large anthropogenic component. Randomly collected soil samples were sequentially taken in order to identify anthropogenic soil formations and to prove the proposed method blind testing has been used. In the specific case of Mas d’Is excavation a recurring question is whether paleosols are at the origin of the human occupation of the sites or it was the occupation of this areas which triggered the paleosols development. Our purpose was to distinguish the degree of human contribution to paleosols formation between samples sequentially taken at few centimeters of distances in a giant stratigraphic sequence (Pit 6) employing REE analysis.
[Show abstract][Hide abstract] ABSTRACT: Volatile compounds released during the production of wine at different steps of the winemaking process were evaluated using semipermeable membranes based passive samplers. Preliminary data on the differences between five wine varieties were provided together with the indoor quality of air to which winery workers are exposed during their professional activity. A simple, green and fast analytical methodology was employed for the direct analysis of deployed samplers by using head space (HS) gas chromatography–mass spectrometry (GC–MS) without any sample pre-treatment and avoiding the use of solvents. Terpenes as styrene, pinene, p-cymene and limonene were found at concentration levels ranging from 3 to 577 ng m− 3 and benzene, toluene, ethylbenzene, and xylenes (BTEX) were also detected at concentration levels between 13 to 525 ng m− 3 for samplers deployed inside containers. Only BTEX below 52 ng m− 3 was detected in the working ambient air.
[Show abstract][Hide abstract] ABSTRACT: Toxic substances such as veterinary drugs, mycotoxins, plant toxins and ergot alkaloids are frequently present in animal feed due to their misuse or also because of the environment. The monitoring and analysis of the presence of these potentially hazardous chemicals remains one of the main tasks to ensure feed safety. Thus, the trend to guarantee quality and safety of feedstuff is going towards targeted screening approaches using high resolution mass spectrometry (HRMS). In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue quantitative screening of veterinary drugs and other contaminants such as undesirable substances regulated by the European Union in feed, using an Orbitrap Exactive™. A database including the elemental composition, the polarity of acquisition, retention time and expected adducts was built for the targeted analysis of around 70 substances. High mass accuracy minor than 5 ppm was set as one of the identification criteria. A "one step" sample clean-up procedure was developed based in the QuEChERS methodology allowing the extraction of a wide range of molecules. An efficient chromatography was achieved using ultra high performance liquid chromatography with Thermo Hypersil Gold 100x2.1 mm 1.9µm column with a run time of 15min. The suitability of full scan HRMS method for screening and confirmatory purposes was evaluated.
6th International Symposium on Recent Advances in Food Analysis; 11/2013
[Show abstract][Hide abstract] ABSTRACT: Pesticides in the inhalable fraction of particulate matter (PM10) should be well tracked in order to contribute information to future exposure assessment in individuals of the general public. A total of 40 current-used pesticides and metabolites were searched for in ambient air samples collected from January through December 2010. The samples were taken from one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed using liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). In the PM10 fraction 17 pesticides and metabolites were detected overall, two of them currently banned (carbofuran and omethoate, although the latter is a metabolite of the permitted pesticide dimethoate). The detected pesticides appeared at frequencies ranging from 1 to 75%, with omethoate, terbuthylazine and its metabolites, and carbendazim presenting the highest frequencies. The concentrations detected ranged from few pg m−3 to thousands of pg m−3, with omethoate having the highest average concentration (141.15 pg m−3) in the 5 sites overall. Each station showed its own specific pesticide profile, which is linked to the different types of crops around each site. In the rural stations pesticide levels were greater in spring and early summer, which correlates with their application in agricultural practices. These findings suggest that more efforts are required to implement an extensive air monitoring network in Europe for pesticide control and to develop regulations or recommendations regarding safer pesticide levels in ambient air.
[Show abstract][Hide abstract] ABSTRACT: In this work, a study was performed to evaluate the use of Amberlite XAD resins (XAD-2, XAD-4 and XAD-16), for the first time, as filling materials for low-density polyethylene membranes, which will be inserted as passive samplers for polycyclic aromatic hydrocarbons (PAHs) in gas phase. The use of samplers deployed for 48 h evidenced a relative capability to retain the compounds under study. A detailed study was performed to evaluate the recovery of analytes from the sampler through microwave-assisted extraction by using acetonitrile. A clean-up step using alumina-C 18 cartridges was necessary before determination of the PAHs by high performance liquid chromatography with fluorescence detection. The limits of detection were of the order of μg L −1 with relative standard deviation values that varied from 1 to 16% as a function of the compound and the XAD resin employed. Amberlite XAD resins can be considered an excellent alterna-tive as filling material of semipermeable membrane devices for passive sampling of PAHs in air due to their low cost, ease of manipulation and suitable chemical and mechanical characteristics.
[Show abstract][Hide abstract] ABSTRACT: Abstract
The aim of this study was to define a strategy for a correct selection of bone samples by employing inductively coupled plasma optical emission spectroscopy (ICP-OES) for reconstructing the biological mineral content in bones through the determination of major elements, trace elements and Rare Earth Elements (REE, lanthanides) in skeletal cremains of ancient Iberians (III–II B.C), discovered in the Necropolis of Corral de Saus (Moixent, Valencia) between 1972 and 1979. The biological mineral content was determined taking into account diagenetic factors. A control method for a better reading of results was applied. To explore large geochemical datasets and to reduce the number of variables, Principal Component Analysis (PCA) was used, thus, providing a deeper insight into the structure of the variance of the dataset. PCA shows that the elemental profiles of bone and soil samples are clearly different. Bone samples obtained from the outer bone layer were shown to have a different elemental composition; more similar to soil samples than samples of the inner bone layer. PCA scores and loadings plots were preferred to dendrograms obtained using Cluster Analysis, due to the limits of the latter one to appreciate the spatial ordering of samples. Partial least squares discriminant analysis (PLS-DA), a frequently used supervised classification method, was applied to differentiate between degradation states of bone samples. PLS-DA results obtained in this study confirmed that changes derived from different burning conditions were associated with transformations in the mineral part of the bones. Accordingly, carbonized bones can be differentiated from cremated bones. Class assignment of bone samples with uncertain thermal conditions in dependence on their elemental composition has shown to be feasible. Consequently, for biochemical-archaeological studies the analysis and statistical classification of carbonized and cremated archaeological bones, as well as those exposed to unknown thermal conditions together with experiments in modern bones, are recommended.
[Show abstract][Hide abstract] ABSTRACT: On occasions, archaeologists have to deal with serious difficulties to differentiate between processes that ultimately are responsible for the formation of stratigraphic units. Sometimes we face problems related with depositional units in multilayered deposits and other times, they ask for the character of some dark surface soils, very similar to natural paleosols and usually associated with archaeological findings. In both cases, the problems we must address concern the relative impact of human activities. The imbalance between anthropic and natural processes in the formation of archaeological deposits is crucial for a correct interpretation of the processes involved in the formation of archaeological sites, but also of their occupation-abandonment dynamics and the understanding of their spatial behaviors and relationship with the environment.In this paper we propose a new methodological approach for the identification of anthropogenic fingerprints in stratigraphic units through Rare Earth Elements (REE) soil analysis. The role of REE for the effective identification of sediment provenance due to their coherent behavior during weathering, erosion and fluvial transportation and their high resistance to chemical mobilization is well known in other areas of knowledge. We try to explore its potentiality in a challenging archaeological context. Our purpose was to identify human traces in stratigraphic units where archaeological materials are scarce or absent intertwined with others richer in archaeological remains by the determination of multiple elements and statistical studies. We believe that Rare Earth Elements (REE) soil analysis provides unique insights for a better characterization of natural and archaeological sediments but more importantly to recognize different stages of the gradient. We expect to discern between natural versus anthropic units and between primary versus secondary deposits (redeposition), using the case of the Neolithic site of Mas d’Is (Alicante, Spain) as an example. The application of the Principal Component Analysis (PCA) remarks differences in REE values, those analysis show differences between units of undoubtedly anthropogenic origin and control samples taken from natural sediments –including marls bedrock–, in their vicinity, but also we could notice finer nuances like the degree of human contributions to paleosols formation.
[Show abstract][Hide abstract] ABSTRACT: The state of the art of passive sampling monitoring studies of atmospheric contaminants is reviewed in this chapter. The following passive samplers were considered: badge-type diffusive samplers; diffusive tubes; semi-permeable membrane devices; Radiello samplers; solid-phase microextraction fibers; polyurethane foam disks; XAD-2 passive air samplers; stir-bar samplers; polymer-coated glass surfaces; versatile, easy and rapid atmospheric monitor; and vegetation. A summary of the passive samplers used, sampling times, sampling rates, and analyte concentrations found is provided for different organic compounds, such as: carbonyl compounds, volatile compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polybrominated diphenyl ethers, pesticides, and other emerging pollutants. The analytical methods for the determination of the analyte concentration in every sampler are presented, revealing good acceptance of environmentally friendly methodologies. Equilibrium and nonequilibrium uptake models are evaluated, taking into account the influence of environmental factors.
Comprehensive Sampling and Sample Preparation, Edited by Editor-in-Chief: Janusz Pawliszyn, 12/2012: pages 201-222; Academic Press., ISBN: 9780123813749
[Show abstract][Hide abstract] ABSTRACT: Better knowledge of the occurrence of pesticides in the inhalable fraction of particulate matter (PM10) could be very useful for future exposure assessment in individuals of the general public. The present work studies the spatial and temporal distribution of the occurrence of currently used pesticides (CUPs) in PM10. Ambient air samples were collected from January through December 2010 at one remote, one urban and three rural sites in Valencia Region (Spain) and analyzed for 42 CUPs using a gas chromatography coupled to mass spectrometry in tandem (GC–MS/MS) approach. Overall, 24 pesticides were detected in the PM10 fraction, four of them currently banned pesticides. Among those detected, concentrations of two particle-bound pesticides (permethrin and pyrimethanil) were, to our knowledge, reported for the first time in air in the literature. The detected pesticides appeared at frequencies ranging from <1 to 47%, with chlorpyrifos, bifenthrin and diazinon presenting the highest frequencies. The concentrations detected ranged from a few to several hundred pg m−3, with ethoprophos showing the highest average concentration (149.2 pg m−3). Each station shows its own specific pesticide profile, which is linked to the different types of crops around each site. Seasonal patterns were observed in the rural stations of Alzira and Sant Jordi, correlating pesticide detection with their application in agricultural practices, mostly in spring and early summer. These findings suggest that more efforts are required to implement an extensive air monitoring network in Europe for pesticide control and to develop regulations or recommendations regarding pesticide levels in ambient air.
[Show abstract][Hide abstract] ABSTRACT: A simple, fast and green direct analytical methodology has been developed to evaluate the concentration level of volatile organic compounds (VOCs) in indoor areas of vehicle repair shops using membrane devices as passive samplers. VOCs retained in the samplers were directly determined without any sample pre-treatment and avoiding the use of solvents by head space (HS) coupled to gas chromatography-mass spectrometry (GC-MS) in only 20 min. Benzene, toluene, tetrachloroethene, m,p-xylene and o-xylene were found at concentration levels from 0.1 to 11.2 mg m(-3).
[Show abstract][Hide abstract] ABSTRACT: In this work, an ultra high performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) methodology is proposed for the multi-class multi-residue screening of banned and unauthorized veterinary drugs in bovine urine, using an Orbitrap Exactive™ analyzer working at a resolving power of 50,000 FWHM in full scan, both in positive and negative mode. The method currently covers 87 analytes belonging to different families such as steroid hormones, β-agonists, resorcylic acid lactones (RAL), stilbens, tranquillizers, nitroimidazoles, corticosteroids, NSAIDs, amphenicoles, thyreostatics and other substances such as dapsone. A database including the elemental composition, the polarity of acquisition, retention time and expected adducts was built for the targeted analysis, and a high mass accuracy (<5ppm) was set as one of the identification criteria. After comparing different sample preparation procedures, QuEChERS was selected as the most appropriate methodology. An efficient separation of analytes was achieved using ultra high performance liquid chromatography with a column packed with sub-2μm particles. The performance of the method has been evaluated in accordance with the EU guidelines for the validation of screening methods for the analysis of veterinary drugs residues. The screening target concentrations were established between 0.2μg/l and 20μg/l, demonstrating the usefulness of UHPLC-HRMS as an ideal tool for compliance monitoring in regulatory laboratories.
Journal of Chromatography A 08/2012; 1258:55-65. DOI:10.1016/j.chroma.2012.08.031 · 4.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A new passive sampler based on low-density polyethylene (LDPE) layflat tube filled with chrome shavings from tannery waste residues was evaluated to determine volatile organic compounds (VOCs) in indoor and outdoor areas. VOCs were directly determined by head space-gas chromatography-mass spectrometry (HS-GC-MS) without any pretreatment of the sampler and avoiding the use of solvents. Limit of detection values ranging from 20 to 75 ng sampler
and good repeatability values were obtained for VOCs under study with relative standard deviation values from 2.8 to 9.6% except for carbon disulfide for which it was 22.5%. The effect of the amount of chrome shavings per sampler was studied and results were compared with those obtained using empty LDPE tubes, to demonstrate the capacity of chrome shavings to adsorb VOCs.
Journal of Analytical Methods in Chemistry 07/2012; 2012(12):897872. DOI:10.1155/2012/897872 · 0.79 Impact Factor