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The Identification of 2-Phenoxyethanol in Ballpoint Inks Using Gas Chromatography/Mass Spectrometry - Relevance to Ink Dating
Abstract
Developing and implementing a generally accepted procedure for the dating of ink found on documents using dynamic approaches has been a very formidable undertaking by forensic document examiners. 2-Phenoxyethanol (PE), a common volatile organic compound found in ballpoint inks, has been recognized for over a decade as a solvent that evaporates as ink ages. More recently, investigations have focused on the solvent loss ratio of PE prior to and after heating. To determine how often PE occurs in ink formulations, the authors analyzed 633 ballpoint inks utilizing a gas chromatograph/mass spectrometer. 2-Phenoxyethanol was identified in 85% (237/279) and 83% (293/354) of black and blue inks, respectively.
... However, these procedures were costly, lengthy and need an alliance with ink industries and hence get closed soon. Again, in 2002, this program is restarted by the US Secret Service [3]. In many countries no such programs are available. ...
... GCMS, on the contrary, has been used for qualitative and quantitative [18,28] purposes. It is also used to study the drying phenomenon of solvents [3]. In most of the cases, the detector used for GC is MS, though FID has been also discussed in few reports [29,30]. ...
The dating of questioned document is a firmest problem for forensic experts. The current work is focused on the study of the dating of ink samples by using spectrophotometry technique and multiple regression analysis. A multiple linear regression (MLR) model has been proposed for the estimation of blue ballpoint pen ink dating by measuring the fading of ink with respect to time using UV–Vis spectrophotometer. Before developing the model, the factors like the best solvent for ink extraction and the conditions through which maximum ink is extracted has been determined. All the samples have been treated with the same method to avoid differences caused by the extraction procedure.
... Maintaining evidence in procedural processes is also important in analyzing the document under discussion. The decomposition methods used to examine the document include thin layer chromatography (TLC), high performance liquid chromatography (HPLC) (Tebbett, Chen, Fitzgerald, & Olson, 1992), optic electrophoresis (Zlotnick & Smith, 1998), gas chromatography with mass spectrometer detector (GC / MS) (LaPorte, Wilson, Cantu, Mancke, & Fortunato, 2003), mass spectrometers with electrospray ionization, field depletion and laser absorption ionization matrix (Braz, López-López, & García-Ruiz, 2014;J. Siegel, Allison, Mohr, & Dunn, 2005) and less invasive techniques such as FTIR, Raman spectroscopy, near-infrared ultrasound imaging (Silva et al., 2014), And atomic force microscopy (Brandão et al., 2016). ...
Forensic chemistry is a field of chemistry containing various branches of chemical science such as analytical, organic and inorganic chemistry. Besides, the new studies of chemistry in accordance with the nanoscience have been also employed to detect forensic facts. Among them, the methods related to analytical chemistry were more attended for forensic applications. Analytical chemistry as the both of classical and instrumental techniques are used in numerous fields of forensic chemistry including drug detection, biological samples of blood, sperm and urine, identification of fake documents, fingerprint, poisons, and gunshot residues. Hence, the coupling of separating techniques, spectroscopy, and computational data has opened a beneficial view rather than the forensic chemistry and its applications for crime scenes. In the present report, some of applications of forensic chemistry for numerous facts were studied as a reviewable investigation.
... Since its first use for writing in Egypt, ink composition has continuously evolved. Formerly, it was extracted from carbonized organic substance (LaPorte, Wilson, Cantu, Mancke, & Fortunato, 2004). Currently, inks are formed from a mixture of dye or pigment with aqueous or glycol-based suspensions (Cai et al., 2019;Xiong & Liu, 2012). ...
Printed electronics (PE) is one of the most dynamic technologies in the world. It proposes low-cost electronic network production in flexible substrates by numerous printing techniques, (screen printing, gravure, offset, flexographic, and inkjet printing), used in various industries. In PE, ink pigments are replaced by metallic particles or precursors that transmit electrical conductivity to the printed patterns such as carbon, polymers and conductive pigments. Conductive inks play an important role in printed electronics, and despite the number of conductive ink types available on the market, there are still issues to be addressed. Some of these restrictions include the use of toxic chemical reagents and solvents and complicated manufacturing protocols, which often make the industrialization of conductive inks an even more distant goal. In particular, conductive inks based on silver nanoparticles, Graphene and PEDOT:PSS are widely studied thanks to their high electrical conductivity. On the other hand, there is still work to be done to show the interest of inks based on phthalocyanine pigments, in particular copper phthalocyanine. Nevertheless, problems related to stability, dispersion and annealing temperature often limit the application of these four types of fillers. In this review, we present general information on available conductive fillers used for the formulation of conductive inks, focusing on metallic particles, carbon fillers, pigments and polymers. The influence and technical requirements of the regularly used printing techniques, as well as the post-processing treatments to achieve the targeted performance in the obtained inks have been discussed. In addition, the surface characteristics of the various types of extensible and flexible substrates used in portable electronics are described. Moreover, some types of printed flexible electronic components as well as notable applications of electronic textiles in various sectors are exhibited. Next, the major challenges for the manufacturing of printed flexible electronics and recommendations for future research are discussed in this review
... It was thought that the structural similarity of 2-PE to dodecantreinol, the main compound of the trail pheromone of glycol compounds contained in these formulations of Coptotermes formosanus and Reticulitermes spp., may be the reason for its appeal to termites. 2-PE has other favourable attributes ─ it is relatively inexpensive, stable, and does not evaporate too rapidly after LaPorte et al., 2004., LaPorte andStephens, 2012). The present study reports the effect of 2-PE trails on the termite species H. obscuriceps. ...
Hypotermes obscuriceps is the most abundant of termite species found in North-eastern Puducherry. It has been seen
to assimilate ligninous waste kept for degradation in the termireactors designed earlier by the authors by the process
of termigradation. Termigradation is a termite-based biodegradation process and involves attracting termites
towards the ligninous waste in specially designed reactors. Such reactors are kept in pits or aboveground near termite
mounds. In order to increase the number of termites that will move towards the feed kept in such termireactors, 2-
Phenoxyethanol (2-PE) was explored in the laboratory for making trails that may attract H. obscuriceps. Five different
concentrations of 2-PE, ranging from 0.1 to 0.0005% were explored and in controlled experiments, the numbers of
termites that followed the trails made by these levels of 2-PE as a function of time were determined. It was seen that
all the trails that contained 2-PE attracted H. obscuriceps and none was toxic to termites for the first 60 minutes.
... Various analytical methods have been used for the purpose of examination of ink's composition. Various nondestructive techniques such as the video spectral comparator, Raman spectroscopy [10][11][12][13][14][15], luminescence spectroscopy [16], and destructive techniques such as liquid chromatography [17,18], capillary zone electrophoresis [19,20], gas chromatography [21], mass spectrometry [22][23][24], and gas chromatographymass spectrometry (GC-MS) [25,26] have been reported to analyse the ink samples. Although gas chromatography-mass spectrometry (GC-MS) is a destructive technique, it has the advantage of enormous adaptability recognition to sensitivity for forensic inks. ...
In developing countries, the chances of fraud in written documents are comparatively high. Therefore, comparison of fountain pen inks is especially imperative in examination of forensic questioned documents. We have investigated the use of the gas chromatography-mass spectrometry technique in profiling and discrimination of fountain pen ink used in Pakistan for forensic purpose. The main purpose of this study was to discriminate different Pakistani fountain pen inks. The datum for Pakistani inks of fountain pen is not obtainable. In this research study, blue, black, and green colors fountain pen inks commercially used in Pakistan have been extracted from paper using micropunch and then investigated using the gas chromatography-mass spectrometry technique. Gas chromatography-mass spectrometry (GC-MS) was used to differentiate various brands of different colors of fountain pen inks based on their chemical composition. Molecular ion peaks for different components were obtained, and components were identified on the basis of detected ions. Results have been calculated and compared in terms of discriminating power (D.P.). The D.P. for blue, black, and green inks of fountain pen was 1.0 by using the gas chromatography-mass spectrometry technique.
... Ink solvent mixtures and print media were improved and optimized. LaPorte et al. 64 investigated the solvent de¯ciency rate of phenoxy ethanol (PE), a common volatile organic compound obtained before and after heating in inks. To determine how often PE occurs in ink formulations. ...
Hot impinging air jets are usually used to increase heat and mass transfer. The dehydration of materials is a procedure of common significance in the chemical processes, forensic science and food industries; in the fabrication of paper, plastics and textiles as well. Effective drying of thin ink films is becoming progressively significant in the quickly development printing, packaging and coating industries. In order to minimize capital and operating cost, variables need to be optimized. For both researchers and commercial dryers, an optimization of the nozzles under striking air jets is offered for ink drying. To supply information to industrial users, a comprehensive literature review was presented to the research. An outline of the previous work of impinging air jets is also given.
... 2-Phenoxyethanol is a common volatile compound which is found in about 80% of ballpoint inks and evaporates with ageing of ink. They examined 633 ballpoint inks using GC/MS and were able to successfully identify 85% of black ink [6] samples and 83% of blue ink samples . Weyermann et.al. ...
... Для обнаружения растворителей и красителей в шариковых чернилах на бумаге требуется чувствительный и селективный аналитический прибор. Газовая хроматография в сочетании с масс-спектрометрией (ГХ-МС), а также высокоэффективная жидкостная хроматография (ВЭЖХ) с диодно-матричным детектированием являются наиболее ча-сто используемыми методами анализа растворителей и красителей соответственно [17][18][19][20][21][22][23][24]. Кроме того, спектроскопические методы, такие как инфракрасная спектроскопия (ИК) и Рамановская спектроскопия (КР), также нашли свое применение для исследования времени нанесения штрихов на бумагу [2][3]. ...
... It was thought that the structural similarity of 2-PE to dodecantreinol, the main compound of the trail pheromone of glycol compounds contained in these formulations of Coptotermes formosanus and Reticulitermes spp., may be the reason for its appeal to termites. 2-PE has other favourable attributes ─ it is relatively inexpensive, stable, and does not evaporate too rapidly after LaPorte et al., 2004., LaPorte andStephens, 2012). The present study reports the effect of 2-PE trails on the termite species H. obscuriceps. ...
Hypotermes obscuriceps is the most abundant of termite species found in North-eastern Puducherry. It has been seen to assimilate ligninous waste kept for degradation in the termireactors designed earlier by the authors by the process of termigradation. Termigradation is a termite-based biodegradation process and involves attracting termites towards the ligninous waste in specially designed reactors. Such reactors are kept in pits or aboveground near termite mounds. In order to increase the number of termites that will move towards the feed kept in such termireactors, 2-Phenoxyethanol (2-PE) was explored in the laboratory for making trails that may attract H. obscuriceps. Five different concentrations of 2-PE, ranging from 0.1 to 0.0005% were explored and in controlled experiments, the numbers of termites that followed the trails made by these levels of 2-PE as a function of time were determined. It was seen that all the trails that contained 2-PE attracted H. obscuriceps and none was toxic to termites for the first 60 minutes.
... The compound 2-phenoxyethanol is the most widespread solvent in ballpoint pen inks [36,43,44] and therefore most dating methods finally focused exclusively on the analysis of this specific substance (Fig. 2). ...
T HE in Egypt. STUDY Eight of aging ballpoint of valuable pens; commonly documents used is asked in Egypt by the were Forensic chosen Medicine for this study. The aging was studied kinetically by measuring the solvent concentration of 2-phenoxyethanol overtime by the GC-MS. The ink aging curves were plotted, using the solvent volatility ratio was an effective method of determining the chronological age of the ballpoint pen inks. Our technique was demonstrated by examining two printed forms of the trust receipts. It was found that determining the ink date is valid and can be trusted. A simple equation that can be applied for the prediction of ink dating was proposed.
... The major peak corresponds to 2-phenoxyethanol (t R = 10.9 min) and the other corresponds to the secondary constituent 2-(2-phenoxyethoxy)ethanol (t R = 13.2 min). According to LaPorte, Wilson, Cantu, Mancke, and Fortunato (2004), the 2-phenoxyethanol pattern should contain up to 10% of the secondary constituent, however, levels above 21% were reported. Despite the presence of 2-(2phenoxyethoxy)ethanol in the chromatographic analysis, this compound was not investigated in this study. ...
... In recent past, numerous studies have come up with various analytical methods to differentiate writing inks. Some of them uses separation techniques which include thin-layer chromatography, [4,5] and capillary electrophoresis (CE) [6][7][8] to analyze the different dye components, with gas chromatography-mass spectrometry (GC-MS) [9][10][11] and high-performance liquid chromatography (HPLC) [12,13] to identify the volatile vehicles of the inks. Other methods, such as infrared [4,13,14] and Raman spectroscopy [15][16][17] are also utilized to examine the ballpoint pen inks for dyes and the pigments identification. ...
The multivariate analysis methods have recently gained high popularity within the field of forensic sciences because of their high accuracy and precision. The accurate and unbiased results are the preliminary need for a forensic investigation. The aim of the present work is to examine the marker pen inks which are widely used in various places like documentation in parcels, for photograph attestation, and also as a study material in the classroom. This research is focused on the three important aspects; first is to characterize the marker inks, second, to discriminate permanent marker and whiteboard marker inks using destructive (extracting of ink samples from paper substrate) and nondestructive (without ink extraction) techniques of ultraviolet–visible absorbance combined with peak identification examination as well as chemometric methods, and the third is to build a classification model for permanent and whiteboard marker inks. It is concluded that the chemometric method, that is, principal component analysis provides better discrimination power as compared to visual examination. However, destructive and nondestructive approaches give almost similar discriminating power. The classification model developed using linear discriminant analysis provides 87.5% of correct classification of marker ink samples. The method can further be used to formulate a statistical model for the determination of class/group of the other forensic exhibits.
... The combined use of TLC and GC-MS has solved two actual cases of alteration. Several research works have reported the characterization of blue ballpoint pen inks manufac- tured in different parts of the world [17][18][19][20]. However, very limited research has been conducted to differentiate the ballpoint pen inks of other colours, such as red and black. ...
The questioned document examiners usually encounter cases related to handwritten documents for the determination of their source, origin, and authenticity. The legal documents usually involve handwriting or signatures executed using ballpoint pens. These components of the ballpoint pen inks can be analysed, both qualitatively and quantitatively, using several techniques. The present study aimed to analyse the red and black ballpoint pen inks using high performance thin layer chromatography and gas chromatography-mass spectrometry techniques. All samples have been completely differentiated using high performance thin layer chromatography. The discrimination potential of gas chromatography-mass spectrometry for red and black ballpoint pen inks was found to be 32.85% and 63.58% respectively. Classification of inks has been performed in two levels, that is, primary differentiation on the grounds of major components of the ink and subsequent differentiation on the basis of minor components. The validity of technique was tested in terms of repeatability and reproducibility. Reproducibility has been determined by repeating the procedure of repeatability on different days. The results have been evaluated in terms of relative standard deviation (RSD), which is
... These compounds diminish over time and most of them will evaporate in a few minutes after being deposited on the support. The maximum prediction time of these methods are two years, since after that time the ink volatile components stabilize and no further changes can be detected [6,9,12,[16][17][18]. Nevertheless, DATINK method is an exception that allows for dating of up to five years old documents, written by ballpoint pen inks, using Multiple Headspace Solid-Phase Microextraction (MHS-SPME) coupled to GC/MS technique [11]. ...
The main methods for dating ballpoint pen inks in questioned documents used up to day are based mainly on the analysis of ink volatile components. These methods have some limitations still unresolved, such as the impossibility for dating documents older than two to five years and the destruction in part or totally of the questioned document after the analysis. This study aims to overcome these drawbacks by exploring the feasibility of dating inks based on their spectroscopic UV–vis-NIR diffuse reflectance spectra monitoring combined with a Partial Least-Squares (PLS) multivariate modelling. Inoxcrom® ink samples were exposed to artificial aging, their reflectance spectra were measured and a multivariate calibration was applied. Mathematical pretreatments of the spectroscopic data were carried out to enhance the prediction ability of the models and the qualitative interpretation of the spectra. The best PLS model was obtained after SNV spectral filter. Accurate predictions (RSD of 25%) were obtained for two of the five pen inks analysed and a correlation between the natural aging and the accelerated artificial aging could be established. Moreover, the spectra region more closely related to the ink aging process could be delimited, in which younger inks were characterized by modifications in the visible and NIR spectra region, while after aging the most influential region was the NIR spectrum. The mismatch with the other three pen inks tested could be attributed to consistent differences in ink formulations. Inks sharing a common chromatographic profile proved to fit correctly in the predictive model indicating that the methodology shows a great potential for future applications in the field of questioned documents dating.
... These applications include the analysis of: bodily fluids and illicit drugs [116,[196][197][198][199][200][201][202][203][204], fire debris [58,59,62,65,67,[191][192][193][194][205][206][207][208][209][210][211][212], explosives [195], inks [213][214][215][216][217][218][219][220], paints [22,24,28,33,221] and other applications [222]. ...
... volatilization volatilization Figura 13 Procesos simultáneos que se dan posteriores a la adición de tinta en el papel. (Weyermann et al., Se han implementado varios métodos para establecer la antigüedad absoluta o relativa de la tinta sobre un documento, dichos métodos se basan en la cromatografía de gases acoplada a la espectrometría de masas (gas chromatography/mass spectrometry -GC/MS) métodos siguen el secado de los disolventes (La Porte et al., 2004), una vez se ha depositado la tinta desde el bolígrafo sobre le papel. Dichos métodos son promisorios debido a su reproducibilidad. ...
Introducción esfuerzo del país a nivel latinoamericano por la implementación de cátedras de pregrado y la creación de posgrados universitarios orientados hacia la investigación criminal y criminalística. Además, se registra en el país un aumento de la demanda de soporte técnico que pueda adaptarse a las necesidades particulares de su contexto, ya que los laboratorios forenses están sometidos diariamente a grandes volúmenes de trabajo, sus recursos son limitados y deben cumplir con normas técnicas y de certificación, de acuerdo con las disposiciones legales. Estas condiciones estimulan la oferta de servicios innovadores y que generen avances en la ciencia, la tecnología y la instrumentación para el uso forense. Un ejemplo de las condiciones mencionadas anteriormente, es cuando a un laboratorio se le solicita determinar la fecha en la que se realizó una modificación de un documento con tinta; este ha sido un problema central en el examen de documentos cuestionados. La datación de tintas se basa en la determinación de sus componentes y la evaluación del cambio de los mismos a través del tiempo, determinando el contenido de disolvente de la tinta presente en el documento (Brazeau et al., 2007; Djozan et al., 2008); técnicas de muestreo como la microextracción en fase sólida junto con la cromatografía de gases y la espectrometría de masas (GC-MS) se han utilizado para cuantificar la cantidad de disolvente en una tinta que ha sido depositada e n u n d o c u m e n t o , c o n e s t e t i p o d e metodologías es posible determinar la presencia de disolventes de tintas en documentos y establecer su antigüedad sin alterar la evidencia (Brazeau et al., 2007). El enfoque investigativo al respecto se ha desarrollado en los laboratorios del FBI y de otros países del primer mundo utilizando diferentes técnicas de análisis como la electroforesis capilar (Vogt et al. 1999), c ro m a t o g r a f í a d e m a s a s a c o p l a d a a espectrometría de masas (LaPorte et al., 2004), espectroscopia de masas de electrospray (Ng et al., 2002) en la búsqueda de alterar al mínimo la evidencia y tener resultados más exactos que aporten a la solución de casos de fraude. El examen de los documentos cuestionados es un constante desafío a las ciencias forenses, frente a la moderna tecnología de la fabricación de documentos cada vez más sofisticados y a la alteración de los mismos. Las múltiples facetas de documentos modernos exigen muchas áreas de especialización y de expertos forenses, a fin de identificar y autenticar un documento cuestionado. Aunque en la actualidad son cada vez más los casos en los que se utilizan documentos electrónicos, los documentos tradicionales (papel) todavía tienen un lugar importante y una gran variedad de tipos diferentes son usados para propósitos de documentación. La amenaza de la alteración ilegal de documentos existe y siempre existirá. El examen de documentos cuestionados es un reto actual en las ciencias forenses, ya que las tecnologías de manufactura de documentos se modernizan continuamente y además las técnicas de alteración son cada vez más sofisticadas. La falsificación de billetes y otros documentos de las transacciones financieras, así como los visados, pasaportes, tarjetas de identificación, y otros documentos oficiales de seguridad del gobierno, documentos de la industria farmacéutica y de productos de marca, se está convirtiendo en una de las áreas de más rápido crecimiento en el mundo de actividad delictiva. En Colombia existe una gran demanda de soporte técnico sobre el particular, para establecer la antigüedad de tintas en documentos que presuntamente han sido alterados, donde se hace necesario la implementación de análisis químicos que presenten gran exactitud. Se necesita aportar elementos técnicos para contribuir a resolver casos de fraude, ya que existen muchos de estos catalogados como no resueltos debido a que no ha sido posible realizar análisis precisos. Determinar cuándo se ha modificado un documento constituye uno de los aportes más significativos de la química forense y tiene un impacto en la detección de cualquier tipo de fraude, dando lugar no solo a beneficios financieros, sino a la correcta administración de justicia. El análisis e identificación química de diferentes tipos de tintas (patosas, de gel, etc.) constituye una herramienta necesaria en un proceso de examinar documentos fraudulentos, concerniente a los laboratorios forenses. Es necesario implementar metodologías sistemáticas para el desarrollo de análisis de los componentes de tintas en documentos que se base en métodos que preserven o alteren al mínimo la evidencia. El Plan Nacional de Desarrollo 2014 – 2018 propone el escenario de un nuevo país, enmarcado en el proceso del posconflicto y que apuesta por su recurso más valioso: la capacidad y el ingenio de los colombianos. En este sentido, la política de generación de nuevo conocimiento a través de la educación, la Ciencia, la Tecnología y la Innovación (CT+i) se constituye en una herramienta clave para el desarrollo y el crecimiento económico y social sostenible de la Colombia del pos acuerdo de paz.
... In recent past, a number of studies have come up with various analytical methods to differentiate the composition of inks. Some of them uses separation techniques which includes thin layer chromatography (TLC) [4] and capillary electrophoresis (CE) [5,6] to analyze the different dye components, whereas, gas chromatography-mass spectrometry (GC-MS) [7,8] and high performance liquid chromatography (HPLC) [9] to identify the volatile vehicles of the inks. Other methods, such as infrared [4,9] and Raman spectroscopy [10,11] are also utilized to examine the ball point pen inks for dyes and the pigments identification. ...
... Preservation of evidence for litigation processes is also in questioned document analyses of particular importance. Analytical methods that have been applied for document examination include thin layer chromatography [56], HPLC [57], capillary electrophoresis [58], gas phase chromatography coupled with MS [59], MS coupled with electrospray ionization, field desorption or matrix-assisted laser desorption ionization [60][61][62][63] and less invasive technologies like FTIR, Raman spectroscopy and near infrared hyperspectral imaging [64][65][66]. ...
An important aspect of any crime scene investigation is to detect, secure and analyze trace evidence. Atomic force microscopy (AFM) is a nanotechnology that can be used to generate forensic information. This review aims to briefly explain principles of AFM and review potential forensic applications like age determination of bloodstains, fingermark examination, investigation of textile fibers, document forgery detection, gunshot and explosive residues analysis, and pressure sensitive adhesives investigation. Current techniques are highlighted and the usefulness of AFM is discussed. For the examination of gunshot, explosives and pressure sensitive adhesive residues AFM can determine elastic moduli, adhesion forces, energy dissipation, and dielectric properties of trace material, provide synoptic mapping of these characteristics and identify compositions. Phase imaging and force spectroscopy are important options but cannot unravel chemical identities. Forensic relevance of force spectroscopy for red blood cell age estimation is promising but remains to be fully explored. If not affected by surface roughness AFM height imaging may yield complementary information with respect to fingermark, textile and document examinations. For overlapping, (partially) erased marks or mixtures of biological traces phase imaging could provide composition information. If the chemical identity of trace components is important AFM may be combined with (surface/tip enhanced) Raman spectroscopy. Equipped with high resolution optical microscopy AFM(-Raman) technology may become a valuable forensic tool to characterize and understand trace transfer and persistence and to assess condition and age of evidence material. AFM could thus yield additional options for forensic association and assist in forensic analysis at activity level.
... Over the past few years, several techniques have been used to analyze inks and documents. Common, but destructive, methods to analyze ink on documents are separation techniques such as gas chromatography [3][4][5], liquid chromatography [6,7], and thin-layer chromatography [8,9]. These chromatographic tech-niques are destructive due to the required sample preparation methods including cutting strips [8], micropunching holes [9], and pulling ink-bearing fibers [10] from the document. ...
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been coupled to direct analyte-probed nanoextraction (DAPNe) through use of nanomanipulation for the analysis of ink chemistry on documents. DAPNe is first used to extract ink from the document and then deposits the sample on the MALDI plate. Through this method, cutting the document for MALDI-MS analysis is avoided. DAPNe extracts ink from documents with minimal to no visible destruction. Specific dyes and binding agents in the extracted ink are monitored with mass spectrometry. Different matrices, 1, 5-diaminonapthalene (DAN), 2, 5-dihydroxybenzoic acid (DHB), and silver nanoparticles, were tested to compare intensity enhancement of the mass spectra signals. The advantages of using MALDI-MS coupled to DAPNe are shown by characterizing Crystal Violet, Basic Yellow 2, Rhodamine B, and polyethylene glycol from red and blue pens, black pen, and a black inkjet printer cartridge.
... In summary, the extractions were carried out in new 10 mL headspace vials extracting the sample at 90 C for 15 min using a 65 mm PDMS/DVB SPME fiber. The extracted analytes were desorbed for 1 min in the injector of the GC/MS at 260 C. In the evaluation of the number of paper discs, working conditions were selected according to the best performance for PE because it represents a large proportion of solvents used as vehicles for both, gel and ballpoint (black & blue) inks [34]. ...
... Depuis peu, les services secrets américains ont relancé leur programme de marqueurs fluorescents en collaboration avec les industries de fabrication de l'encre [LaPorte, 2004]. Il s'agit d'introduire dans les encres un marqueur différent chaque année qui est facilement analysable. ...
Cet article traite de l’effet des programmes policiers sur la délinquance en milieu scolaire. L’article débute par décrire les différents programmes policiers implantés en milieu scolaire, soit le policier ressource assigné en permanence à une école ou commission scolaire (School resource officer - SRO), le policier éducateur et l’agent de liaison (School liaison officer - SLO). Par la suite, les études évaluatives ainsi que les recensions systématiques et méta-analyses (lorsque disponibles) sont répertoriées afin de statuer sur la capacité des programmes policiers à résorber les problématiques de délinquance en milieu scolaire. Les méta-analyses démontrent que les programmes éducatifs dispensés par les policiers éducateurs tels que DARE (Drug Abuse Resistance Education) et GREAT (Gang Resistance Education and Training) ne produisent que des effets triviaux sur la consommation de drogue. D’autre part, notre propre synthèse des évaluations des SROs et SLOs sème un doute sur l’efficacité de tels programmes. Bien que plusieurs évaluations rapportent une diminution de la délinquance des suites de l’implantation du programme policier en milieu scolaire, les méthodologies comportent de nombreuses limites qui remettent en question la validité des résultats. D’ailleurs, les études les plus rigoureuses obtiennent les résultats les plus pessimistes. D’autres évaluations basées sur des protocoles rigoureux sont requises pour évaluer avec validité les effets des
programmes policiers sur la délinquance en milieu scolaire.
... [20][21][22] Moreover, gas chromatography and mass spectrometry (GC-MS) method has been described as the determination of 2-phenoxyethanol in ballpoint inks. 23 Recently, the method using micellar electrokinetic chromatography has been reported. 24 Alkoxyalcohols that have relatively lower boiling points and higher vapor pressures Abbreviation: 2-methoxyethanol (2MeEtOH), 2-ethoxyethanol (EtE-tOH), 2-propoxyethanol (2PrEtOH), 2-phenoxyethanol (2PhEtOH), 2-(2-butoxyethoxy)ethanol (2(2BuEt)EtOH), 1-methoxy-2-propanol (Me2PrOH), 1-ethoxy-2-propanol (Et2PrOH), 1-propoxy-2-propanol (Pr2PrOH), 1-butoxy-2-propanol (Bu2PrOH), 1-phenoxy-2-propanol (Ph2PrOH), 1-(2-butoxy-1-methylethoxy)-2-propanol (1(2BuMEEt) 2PrOH), (2-methoxymethylethoxy)propanol ((2MeMEEt)PrOH), 3ethoxy-1-propanol (3EtPrOH), 3-methyl-3-methoxybutanol (3ME3MeBuOH) than 2-phenoxyethanol were analyzed by GC-MS. ...
Alkoxyalcohols are used as solvents or preservatives in various consumer products such as wet wipes. The metabolites of alkoxyalcohols are known to be chronically toxic and carcinogenic to animals. Thus, an analytical method is needed to monitor alkoxyalcohols in wet wipes. The aim of this study was to develop a simultaneous analytical method for 14 alkoxyalcohols using headspace gas chromatography coupled with mass spectrometry to analyze the wet wipes. This method was developed by comparing with various headspace extraction parameters. The linear calibration curves were obtained for the method (r(2) > 0.995). The limit of detection of alkoxyalcohols ranged from 2 to 200 ng mL(-1). The precision of the determinative method was less than 18.20% coefficient of variation both intra and inter days. The accuracy of the method ranged from 82.86% to 119.83%. (2-Methoxymethylethoxy)propanol, 2-phenoxyethanol, and 1-phenoxy-2-propanol were mainly detected in wet wipes.
... Usually, handwriting features such as the character shape and the style of writing are important information used for handwriting identification. [2] Alternatively, handwriting verification can be achieved based on ink analysis by using advanced instrumental methods such as thin layer chromatography (TLC), [3][4][5] liquid chromatography (HPLC), [6][7][8][9] gas chromatography (GC), [10] inductively coupled plasma-mass spectrometry (ICP-MS), [11] liquid chromatography-mass spectrometry (HPLC-MS), [12] gas chromatography-mass spectrometry (GC-MS), [13][14][15] Raman spectroscopy [5,16] and Fourier transform infrared spectroscopy [17] etc. Due to the high sensitivity of instrumental analysis, these methods generate rich chemical information and allow improved accuracy of document authentication. Tolerating complex matrices present in actual samples, ambient mass spectrometry [18][19][20] is of increasing interest for the high throughput analysis of actual samples, because little or no sample pretreatment is required. ...
Molecular images of documents were obtained by sequentially scanning the surface of the document using desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS), which was operated in either a gasless, solvent-free or methanol vapor-assisted mode. The decay process of the ink used for handwriting was monitored by following the signal intensities recorded by DAPCI-MS. Handwritings made using four types of inks on four kinds of paper surfaces were tested. By studying the dynamic decay of the inks, DAPCI-MS imaging differentiated a 10-min old from two 4 h old samples. Non-destructive forensic analysis of forged signatures either handwritten or computer-assisted was achieved according to the difference of the contour in DAPCI images, which was attributed to the strength personalized by different writers. Distinction of the order of writing/stamping on documents and detection of illegal printings were accomplished with a spatial resolution of about 140 µm. A Matlab® written program was developed to facilitate the visualization of the similarity between signature images obtained by DAPCI-MS. The experimental results show that DAPCI-MS imaging provides rich information at the molecular level and thus can be used for the reliable document analysis in forensic applications. © 2013 The Authors. Journal of Mass Spectrometry published by John Wiley & Sons, Ltd.
... may be used. Among them, thin layer chromatography, high performance liquid chromatography, microspectrophotometry and capillary electrophoresis have been used [1,2,4,5]. However, these procedures imply sample extraction with organic solvents before characterizing or identifying the organic colorants and do not provide precise comparisons among inks. ...
One of the challenges faced by forensic scientists is to effectively respond to the dynamic markets of writing inks. Through document analyses carried out by the forensic scientists, the requirements of rapid and portable analytical techniques to characterise writing inks has evolved. One such technique is Raman spectroscopy (RS), which is frequently applied as a primary technique for detecting fraud in documents. A new type of writing instrument, the gel ink pen emerged in the early 1980s to replace the ball point pens, and has become the fastest growing pen available in the market. A comprehensive conceptual workflow incorporating chemometrics when high-dimensional dataset is involved has evolved for discrimination of ink. We report the first study ever, employing RS, along with the unsupervised Self-Organising Feature Maps (SOFM) and supervised Partial Least Square Discriminant Analysis (PLS-DA) to distinguish gel inks. Red gel inks collected from 190 samples of red gel pens of various brands were analysed using the Raman spectrometer (FORAM 685-2). A library of Raman spectra containing 200 known pigments was used, which identified Organize Red DPP BO (23180 – CI Pigment Red 254), and XSL Poppy Red (26308 – CI Pigment Red 112) as the colour components of red gel ink pens. Further to the unsupervised SOFM analysis, supervised Partial least square discriminant analysis (PLS-DA) was performed for classification and prediction, whereby most of the assessed pens were correctly classified to a specific pen class (dyes or pigments based). In forensic case scenario, correct prediction rate (100%) for all test samples were observed for red gel inks according to specific pen using the trained PLS-DA model. A high rate of correct source correspondence of the inks to their respective pens was also achieved.
The identification and differentiation of stamp inks can be a crucial aspect to establish the authenticity of questioned documents, and thus plays a vital role in judicial expertise. Herein, 16 brands of blue stamp inks and 12 brands of red stamp inks have been investigated using Attenuated Total Reflectance – Fourier Transform Infrared (ATR FT-IR) Spectroscopy in the mid-IR range. Stamp inks of different brands were differentiated using visual inspection of spectra with discrimination power of 96.6% and 93.9% for blue and red stamp inks respectively. To get enhanced and better discrimination power, chemometric tools such as PCA, PCA-LDA, and PLS-DA were applied, which provided satisfactory results with higher accuracy rate. Further, to check the influence of substrates, imprinted stamp inks on different papers were also analyzed and results have been discussed. Henceforth, the obtained results in the current study illustrates that the technique ATR FT-IR spectroscopy is a sensitive and reliable tool with minimal sample preparation requirements to identify and differentiate different manufactures of stamp inks, thus extends a novel approach to judge the document’s authenticity.
Considering the high use of inkjet printing in forgery cases, the classification of inkjet printing is particularly important in questioned document examination. In this work, a universal GC–MS method has been developed to analyze various ink components extracted from inkjet printouts. The results indicated that several components detected and identified across 195 inks could be used to distinguish printer manufacturers. A trend of decreasing solvent concentration over time was observed through the continuous monitoring of 7 samples. The results shown that this method is useful for forensic classification purposes, and can be useful regardless effects of storage environment, paper or printer. Furthermore, the application of this method in the analysis of counterfeit banknotes illustrated its feasibility and applicability.
No Brasil, peritos criminais e cientistas forenses frequentemente são solicitados a resolver diversos casos que requerem análise de tintas de canetas esferográficas, e no atual estado da arte da perícia criminal não se tem nenhuma técnica em que a determinação da idade de uma tinta aposta sobre um documento seja conclusiva ou eficiente.A datação de um documento pode ser absoluta ou relativa e a literatura apresenta diversas abordagens para efetuar a datação relativa de um documento, partindo geralmente de uma curva padrão com documentos de diversas idades conhecidas, pressupondo que o questionado e o padrão foram submetidos às mesmas condições ambientais. Um dos métodos utilizados é a determinação da dinâmica de evaporação de solventes, entre eles o 2-fenoxietanol, após a aposição da tinta no papel, a qual poderia relacionar-se com a cronologia deste lançamento. Este trabalho buscou verificar se as canetas mais comumente utilizadas no Brasil possuem ou não semelhantes concentrações basais de 2-fenoxietanol na sua formulação, o que poderia, em tese alterar o conteúdo deste entre canetas diferentes de mesma cronologia, alterando desta forma a conclusão do exame de datação de lançamentos. O método utilizado foi o de Cromatografia Gasosa com Detecção por Ionização de Chama, e após as análises, verificou-se que as canetas analisadas apresentavam diferença nas concentrações iniciais de 2-fenoxietanol, e que canetas pretas apresentavam teores mais homogêneos entre si do que as canetas azuis, que apresentaram maior variabilidade.
The development of ink dating methods requires an important amount of work in order to be reliably applicable in practice. Major tasks include the definition of ageing parameters to monitor ink ageing. An adequate parameter should ideally fulfil the following criteria: it should evolve as a function of time in a monotonic way, be measurable in a majority of ink entries, be as accurate and reproducible as possible, and finally it should not be influenced too much by transfer and storage conditions. This work aimed at evaluating the potential of seven ageing parameters for ink dating purposes: the phenoxyethanol quantity, relative peak areas (RPA), three solvent loss ratios (R%, R%*, NR%) and two solvent loss parameters (RNORM, NRNORM). These were calculated over approximately one year for 25 inks selected from a large database to represent different ageing behaviours. Ink entries were analysed using liquid extraction followed by GC/MS analysis. Results showed that natural ageing parameters (NR% and NRNORM) were not suitable ageing parameters for ink entries older than a few weeks. RPA used other compounds present in ink formulations in combination to PE in order to normalise the results. However, it presented particular difficulties as they could not be defined for all inks and were thus applicable only for 64% of the studied inks. Finally, the PE quantity, R% and RNORM allowed to follow the ageing of the selected inks over the whole time frame and were identified as the most promising. These were thus selected to test three different interpretation models in the second part of this article. The possibilities and limitations of ink dating methods will be discussed in a legal perspective.
The development of an ink dating method requires an important investment of resources in order to step from the monitoring of ink ageing on paper to the determination of the actual age of a questioned ink entry. This article aimed at developing and evaluating the potential of three interpretation models to date ink entries in a legal perspective: (1) the threshold model comparing analytical results to tabulated values in order to determine the maximal possible age of an ink entry, (2) the trend tests that focusing on the “ageing status” of an ink entry, and (3) the likelihood ratio calculation comparing the probabilities to observe the results under at least two alternative hypotheses. This is the first report showing ink dating interpretation results on a ballpoint be ink reference population.
In the first part of this paper three ageing parameters were selected as promising from the population of 25 ink entries aged during 4 to 304 days: the quantity of phenoxyethanol (PE), the difference between the PE quantities contained in a naturally aged sample and an artificially aged sample (RNORM) and the solvent loss ratio (R%). In the current part, each model was tested using the three selected ageing parameters. Results showed that threshold definition remains a simple model easily applicable in practice, but that the risk of false positive cannot be completely avoided without reducing significantly the feasibility of the ink dating approaches. The trend tests from the literature showed unreliable results and an alternative had to be developed yielding encouraging results. The likelihood ratio calculation introduced a degree of certainty to the ink dating conclusion in comparison to the threshold approach. The proposed model remains quite simple to apply in practice, but should be further developed in order to yield reliable results in practice.
An extraction and determination method is shown for the analysis of dyes and solvents present in two types of ballpoint pen inks that are deposited onto paper. Ink extracts are analysed using a combination of gas chromatography with mass spectrometry (GC–MS), and high-pressure liquid chromatography with photodiode array detection (HPLC-DAD), within a single sample extraction procedure.
Seventeen solvents and thirteen dyes contained in two Montblanc® inks (black and blue) were monitored for 45 months at monthly intervals, in order to determine variations in the concentrations of the compounds over time. We also studied the relative variations between different compounds and the generation of degradation products such as phenol.
The concentration data obtained from these compounds during their exposure have been analysed and a multiple regression model is developed for each ink type that allows an estimate of the exposure time of the ink on paper with a maximum error of between 4 and 7 months.
This chapter focuses on applications of chemistry related to the materials used to construct a document, such as writing inks, paper, printing inks, and toner. It discusses the evolution of analytical tests used to examine documents, and provides an overview of current methods including strengths, limitations, and the interpretation of findings. The chapter describes two different approaches of using analytical methods for the dating of documents to include the examination of items in or on documents such as inks, papers, and their components: static approach and dynamic approach. Although the emphasis of the chapter is on the chemical analysis of documents, it is critical to understand that physical and optical examinations are requisite before conducting chemical examinations. Crime scenes that involve questioned documents can range from matters of national security to the counterfeiting of a driver's license at the local library.
Many inks of wet stamps and of writing instruments such as ballpoint pens, felt-tip pens or roller pens contain luminescent components. Optical comparison of two or more unknown inks with the aid of IR-camera systems is a standard method in questioned document examination. It has been observed, that these components may migrate within the paper and especially along the stroke of an intersected line with another ink. In this study we describe and discuss the migration of these components.
We could show that migration data can be used for ink dating.
The application of electronic-nose (E-nose) technologies in forensic science is a recent new development following a long history of progress in the development of diverse applications in the related biomedical and pharmaceutical fields. Data from forensic analyses must satisfy the needs and requirements of both the scientific and legal communities. The type of data collected from electronic-nose devices provides a means of identifying specific types of information about the chemical nature of evidentiary objects and samples under investigation using aroma signature profiles of complex gaseous mixtures containing volatile organic compounds (VOCs) released from manufactured products and parts of the human body. E-nose analyses also provide useful qualitative information about the physicochemical characteristics and metabolic conditions of human subjects without the need for time-consuming analyses to identify all chemical components in human-derived volatile mixtures. E-nose devices are capable of providing information for a wide range of forensic applications, useful for answering many types of questions relating to past events and details of circumstances and conditions that led to criminal activities involving human subjects and the perpetrators involved. E-nose devices have been used to help locate live subjects, buried in the rubble of collapsed buildings following natural disasters, as well as hidden bodies and the human remains of victims of accidents and crimes of aggression. The noninvasive analysis of gaseous mixtures in the human breath and lungs of living and deceased individuals provides a means for identifying the existence of diseases or adverse physiological conditions of human subjects (both before death and postmortem) potentially useful in determining the cause of death, time of death, and pertinent factors contributing to lethal events such as homicides and other violent crimes.
For more than a decade scientists tried to develop methods capable of dating ink by monitoring the loss of phenoxyethanol (PE) over time. While many methods were proposed in the literature, few were really used to solve practical cases and they still raise much concern within the scientific community. In fact, due to the complexity of ink drying processes it is particularly difficult to find a reliable ageing parameter to reproducibly follow ink ageing. Moreover, systematic experiments are required in order to evaluate how different factors actually influence the results over time. Therefore, this work aimed at evaluating the capacity of four different ageing parameters to reliably follow ink ageing over time: (1) the quantity of solvent PE in an ink line, (2) the relative peak area (RPA) normalising the PE results using stable volatile compounds present in the ink formulation, (3) the solvent loss ratio (R%) calculated from PE results obtained by the analyses of naturally and artificially aged samples, (4) a modified solvent loss ratio version (R%*) calculated from RPA results. After the determination of the limits of reliable measurements of the analytical method, the repeatability of the different ageing parameters was evaluated over time, as well as the influence of ink composition, writing pressure and storage conditions on the results. Surprisingly, our results showed that R% was not the most reliable parameter, as it showed the highest standard deviation. Discussion of the results in an ink dating perspective suggests that other proposed parameters, such as RPA values, may be more adequate to follow ink ageing over time.
Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
During the last years (2000-2014), many publications concerning the forensic analysis of questioned documents have been published, and new techniques and methodologies are nowadays employed to overcome forensic caseworks. This article reviews a comprehensive collection of the works focused on this issue, including dating studies, the analysis of inks from pens and printers, the analysis of paper, the analysis of other samples related to questioned documents and studies on intersecting lines. These sections highlight the most relevant analytical studies by a wide range of analytical techniques. Separation and spectrometric techniques are critically discussed and compared, emphasizing the advantages and disadvantages of each one. Finally, concluding remarks on the research published are included.
Copyright © 2014 Elsevier B.V. All rights reserved.
An ink dating method based on solvent analysis was recently developed using thermal desorption followed by gas chromatography/mass spectrometry (GC/MS) and is currently implemented in several forensic laboratories. The main aims of this work were to implement this method in a new laboratory to evaluate whether results were comparable at three levels: (i) validation criteria, (ii) aging curves, and (iii) results interpretation. While the results were indeed comparable in terms of validation, the method proved to be very sensitive to maintenances. Moreover, the aging curves were influenced by ink composition, as well as storage conditions (particularly when the samples were not stored in "normal" room conditions). Finally, as current interpretation models showed limitations, an alternative model based on slope calculation was proposed. However, in the future, a probabilistic approach may represent a better solution to deal with ink sample inhomogeneity.
A method for the extraction and analysis of ink samples was developed using microscopy with direct analyte probe nanoextraction coupled to nanospray ionization mass spectrometry (DAPNe-NSI-MS) for localized chemical analysis of document inks. Nanomanipulation can be effectively coupled to nanospray ionization mass spectrometry providing picomolar sensitivity, and the capability to analyze ultra-trace amounts of material and reduce the required sample volume to as low as 300nL. This new and innovative technique does not leave destructive footprints on the surface of a document. To demonstrate the breadth of this technique, analysis of inks from various eras were tested, iron gall ink and modern inks, as well as the capability to detect the oxidative products of polyethylene glycol (PEG), a common binding agent. The experimental results showed that DAPNe-NSI-MS was able to chelate iron(II) and manganese(II) ions of iron gall ink and organic components of modern and carbon-based inks. Regardless of whether the ink composition is modern or ancient, organic or inorganic, this new instrumental approach is able to identify and characterize the ingredients by modifying the extraction solvent, illustrating the potential diversity of the DAPNe technique.
The application of electronic-nose (E-nose) technologies in forensic science is a recent new development following a long history of progress in the development of diverse applications in the related biomedical and pharmaceutical fields. Data from forensic analyses must satisfy the needs and requirements of both the scientific and legal communities. The type of data collected from electronic-nose devices provides a means of identifying specific types of information about the chemical nature of evidentiary objects and samples under investigation using aroma signature profiles of complex gaseous mixtures containing volatile organic compounds (VOCs) re-leased from manufactured products and parts of the human body. E-nose analyses also provide useful qualitative information about the physicochemical characteristics and metabolic conditions of human subjects without the need for time-consuming analyses to identify all chemical components in human-derived volatile mixtures. E-nose devices are capable of providing information for a wide range of forensic applications, useful for answering many types of questions relating to past events and details of circumstances and conditions that led to criminal activities involving human subjects and the perpetrators involved. E-nose devices have been used to help locate live subjects, buried in the rubble of collapsed buildings following natural disasters, as well as hidden bodies and the human remains of victims of accidents and crimes of aggression. The noninvasive analysis of gaseous mixtures in the human breath and lungs of liv-ing and deceased individuals provides a means for identifying the existence of diseases or adverse physiological conditions of human subjects (both before death and postmortem) potentially useful in determining the cause of death, time of death, and pertinent factors contributing to lethal events such as homicides and other violent crimes.
The application of electronic-nose (E-nose) technologies in forensic science is a recent new development following a long history of progress in the development of diverse applications in the related biomedical and pharmaceutical fields. Data from forensic analyses must satisfy the needs and requirements of both the scientific and legal communities. The type of data collected from electronic-nose devices provides a means of identifying specific types of information about the chemical nature of evidentiary objects and samples under investigation using aroma signature profiles of complex gaseous mixtures containing volatile organic compounds (VOCs) released from manufactured products and parts of the human body. E-nose analyses also provide useful qualitative information about the physicochemical characteristics and metabolic conditions of human subjects without the need for time-consuming analyses to identify all chemical components in human-derived volatile mixtures. E-nose devices are capable of providing information for a wide range of forensic applications, useful for answering many types of questions relating to past events and details of circumstances and conditions that led to criminal activities involving human subjects and the perpetrators involved. E-nose devices have been used to help locate live subjects, buried in the rubble of collapsed buildings following natural disasters, as well as hidden bodies and the human remains of victims of accidents and crimes of aggression. The noninvasive analysis of gaseous mixtures in the human breath and lungs of living and deceased individuals provides a means for identifying the existence of diseases or adverse physiological conditions of human subjects (both before death and postmortem) potentially useful in determining the cause of death, time of death, and pertinent factors contributing to lethal events such as homicides and other violent crimes.
The establishment of approaches for the differentiation of the ink entries of seals on paper can provide evidence to authenticate the related documents and can play a key role in judicial expertise. The identification and discrimination method for 38 red ink entries of seals on paper has been investigated using laser desorption ionization mass spectrometry (LDI-MS). Six dye components for the ink pastes of seals, Scarlet powder (SP), Bronze Red C (BR), Fast Red R (FR), Basic Violet 3 (BV3), Pigment Red 22 (PR22) and Pigment Red 112 (PR112), have been identified by their LDI-MS spectra, and the results have been confirmed by electrospray ionization quadruple-time of flight mass spectrometry (QTOF-ESI-MS/MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The 38 ink entries were classified into six groups based on the presence or the absence of the pigments in their positive and negative LDI-MS spectra, and the discrimination power (DP) was calculated to be about 82%. The ink entries within each group were further differentiated from the relative peak areas (RPA) of the fragments for the pigments and the profile of their LDI-MS spectra, and thus the DP was increased to 98%. All the 38 ink entries could be discriminated (the DP was 100%), if including the contribution of unknown peaks. Compared with the results obtained by the FTIR and Raman methods, the established LDI-MS approach could provide more information of the dye components in the ink entries. The results showed that the developed LDI-MS method is powerful, sensitive and rapid and can directly differentiate the red ink entries of seals from paper substrates, thus offering a novel approach to judge the authenticity of documents.
Subterranean termites excavate complex underground tunnels for foraging. Most tunnels comprise primary and secondary tunnels. Tunnels originating from the nest are called primary and those branching from the primary tunnels are named secondary tunnels; tertiary and quaternary tunnels are rarely observed. During foraging, termites may thus encounter a considerable number of tunnel-branching nodes. Directional selection at such a node is likely correlated to tunnel-growth activity because tunnels containing more termites have a higher probability of growth. In this study, we investigated how termites select the direction of movement at an artificially-designed branching node, by making chemical trails on filter paper, drawing lines using a ballpoint pen which contained the chemical substance that induces the termite to follow trails. The trails consisted of two lines: straight and branching. The branching line was drawn from the center of the straight line at an angle θ (10°, 20°,…, 90°). We then calculated the ratio of the directional selection as r = Ns/Nb, where Ns and Nb represent the number of straight and branching tunnels selected, respectively. The values of r were statistically classified into three groups based on the angle of the branching trail, as follows: 10° ≤ θ ≤ 20°, 30° ≤ θ ≤ 60°, and 70° ≤ θ ≤ 90°. Our paper briefly discusses the underlying mechanisms of the experimental results.
Ink analysis is central to questioned document examination. We applied direct analysis in real time mass spectrometry (DART MS) to ballpoint, gel, and fluid writing ink analysis. DART MS acquires the mass spectrum of an ink while it is still on a document without altering the appearance of the document. Spectra were acquired from ink on a variety of papers, and the spectrum of the blank paper could be subtracted out to produce a cleanly isolated ink spectrum in most cases. Only certain heavy or heavily processed papers interfered. The time since an ink is written on paper has a large effect on its spectrum. DART spectra change radically during the first few months after an ink is written as the more volatile components evaporate, but the spectra stabilize after that. A library-search study involving 166 well-aged inks assessed the ability to identify inks from their DART spectra. The aggregate success rate was 92%.
This chapter discusses the chromatographic procedures applied to the analysis and dating of ink on documents. It discusses most recent techniques covered in the scientific literature since the first edition of the Handbook of Analytical Separation was published in 2000. Thin-layer chromatography (TLC) remains one of the principal analytical methods employed by most laboratories in forensic ink analysis. The reason for this is that this method is comparatively simple, rapid, and cost-efficient. In most cases, this method is used to visually evaluate the qualitative and semiquantitative composition of ink dye components separated on the TLC plate. The sample preparation for the TLC analysis of ink is discussed in detail in the chapter. It is recommended that color jet ink be removed from the uppermost layer of paper using a scalpel. This method increases the ink-to-paper ratio and reduces potential contamination from ink on the reverse of the document. Andrasko used the high performance liquid chromatography (HPLC) analysis with diode array detection to monitor changes in the chemical composition of ballpoint-pen inks after exposure to light and under normal aging conditions.
A novel approach for differentiation and dating of red ink entries of seals on documents was developed based on ion-pairing HPLC (IP-HPLC) and GC/MS. Sixty-nine red ink pastes of seals were collected and the chromatographic conditions for separation of the dye components by IP-HPLC and the volatile additives by GC/MS in the ink entries were optimized. According to the dye components and additives, the ink entries were classified by HPLC with a multi-wavelength UV detector. The volatile components of the inks were identified by GC/MS and the classification of the ink entries was also investigated based on these volatile additives. The results showed that most of the ink entries of the seals can be differentiated by combining HPLC with a multi-wavelength detector and GC/MS methods. The degradation of the standard dye mixtures and the compositional changes of the ink entries of seals were investigated in light or natural aging conditions. The results indicated that the dye components decomposed in light or natural storage conditions, while the rates of the degradation depended on the structures of the dye components, the aging conditions, even the additives of the ink pastes. The results also showed that there existed good relationships between the compositional changes of the ink entries and the aging time, which can provide scientific evidences and valuable clues for dating of the ink entries.
Materials such as biological fluids and tissues, fire debris, car paints, and fibers are the most common evidential materials analyzed by forensic chemists and are characterized by a high degree of complexity. Developments in forensic science have introduced many vital crime-solving techniques over the past decades. The introduction of gas chromatography (GC) has broadened the range of available tools, but more importantly, has improved the credibility of analytical findings by demonstrating a high separation power and high sensitivity. GC is often coupled with molecular detection methods such as mass spectrometry, or infrared spectrometry, making it a powerful tool in identification of a wide variety of chemical substances. Some recent applications of GC in the forensic sciences, including those in forensic toxicology, are presented in the article, which include alcohol and drugs in drivers, markers of alcohol abuse, volatiles and anesthetics, carbon monoxide (CO) poisoning, other poisons, drug-facilitated sexual assault (DFSA) and drug profiling, and more general application to criminalistics in areas such as fire debris, car paints, explosives, toners, fibers, inks, and fingermark analysis.
Keywords:
forensic sciences;
analytical chemistry;
gas chromatography;
forensic toxicology;
criminalistics;
trace analysis
The determination of the age of a document is a very frequent query; however, it is also one of the most challenging and controversial areas of questioned document examination. Several approaches were defined to address this problem. The first is based on the introduction date of raw constituents (like paper or ink) on the market. The second approach is based on the aging of documents, which is unfortunately not only influenced by passing time, but also by storage conditions and document composition. The third approach considers the relative age of documents and aims at reconstructing their chronology. The three approaches are equally complex to develop and the amount of problems encountered is not negligible. This article aims to expose the potential applications and limitations of current ink dating methods. Method development and validation and the interpretation of evidence prove to be essential criteria for the dating of documents.
A sketch of several analytical methods for dating documents is provided. These methods analyze items in or on documents; such items include inks, papers, and their components. These methods take two major approaches to dating: the static approach and the dynamic approach. The static approach determines when items in or on a document first came into existence. This approach depends on comparison with reference standards. The dynamic approach involves the aging process. This approach compares the relative aging of items of the same composition and, in most cases, on the same document. Both approaches, analytical and otherwise, have historical origins dating to when documents were suspected of being fraudulent.
Two methods are presented for the identification of ink, both of which are currently being used by laboratories involved in ink analysis. Both methods incorporate physical and chemical procedures. The differences are primarily in chemical methods involving spot tests and thin layer chromatographic (TLC) techniques. Furthermore, one method utilizes spectrophotometric scanning of the TLC plate whereas the other method utilizes solution spectrophotometry. It is recommended that both methods be evaluated by several laboratories.
Solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) was used to characterize the volatile components associated with U.S. currency, U.S. currency inks, and Canadian currency. Compounds that can be attributed to the ink-curing process include series of straight-chain aldehydes, alkenals, acids, alcohols, and ketones and a series of lactones and 2-alkyl furans. Solvent compounds include naphthenic and paraffinic hydrocarbons with a profile typical of petroleum products, alkyl cyclohexanes, various ethylene glycol alkyl ethers, and traces of chlorinated solvents. Trace levels of 2-phenoxyethanol, a solvent often used in ink formulations, were also detected. Environmental contaminants, those compounds found in circulating currency but not in currency ink, include 2,2'-diethyl-1,1'-biphenyl, methyl benzoate and salicylate, menthol, limonene, dimethyl and diethyl plithalate, and ionol. Not including simple hydrocarbons, over 100 compounds were identified in the headspace of currency-related samples.
The headspace profiles of eleven methamphetamine (MA) samples have been analyzed using solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS). Nine of the eleven are illicit MA seizures from the Southwest U.S. border. One sample is methamphetamine base synthesized in the Drug Enforcement Administration (DEA) Southwest Laboratory, and the remaining sample is pharmaceutical-grade methamphetamine hydrochloride that is used to make training aids for drug detecting canines. In addition, volatiles associated with 1-phenyl-2-propanone (P2P), a methamphetamine precursor, have been identified for comparison with those found in methamphetamine seizure and the two reference samples. Eighty-seven different compounds were identified from all the samples, not including simple hydrocarbons and aldehydes. Only seven occur consistently in all seizure samples, and these are: acetic acid, benzaldehyde, acetophenone, P2P, 1-phenyl-1,2-propanedione (P12P), 3-phenyl-3-buten-2-one, 1-chloro-1-phenyl-2-propanone. Dimethyl sulfone, a common cutting agent in methamphetamine, was found in six of the nine seizure materials. When the reference methamphetamine and P2P samples are included, only two compounds are common to all twelve samples, and these are benzaldehyde and P2P. As such, these two compounds are likely candidates for use in a pseudomethamphetamine (PM) formulation, and their effectiveness in eliciting a canine response is being evaluated before actual deployment.
A systematic approach to identification of writing inks is presented. This approach uses a multiple technique method for analysis of the inks to develop a large number of identifiable points for comparison. Well established methods are used for the analysis of inks, such as thin layer chromatography, spectrophotometry, and gas-liquid chromatography, in addition to traditional methods for comparison which use ultraviolet and infrared light. The inks are identified by comparing the results of the questioned inks with results obtained from a complete library of writing inks maintained by this laboratory. By using the described approach, most inks can be identified with a high degree of certainty.
Ballpoint pen inks consist primarily of a mixture of dyes, resins, and vehicle components. The vehicles are used to solubilize or suspend dyes, resins, and other components as well as to provide smooth ball movement and flow of ink onto writing surfaces. These vehicles are relatively volatile and make up approximately 50% of the ink by weight. Extraction and formulation identification of the questioned ink is performed. Once identified, the volatile components of the ink are measured quantitatively by gas chromatography. Preliminary studies show that the relative proportions of these volatile ingredients decrease as the ink ages. How long an ink has been on paper is determined by comparison of the relative concentrations of the volatile components of the questioned ink with those of known inks (age) of the same formulation. The relationship between age of ink, storage conditions, and paper will also be discussed.
A three-step thin-layer chromatographic procedure for examining colored components of printing and writing inks and other marking materials is described. The procedure uses the original stage of separating phthalocyanine pigments and other 'slightly soluble' organic pigments. Experimental conditions are given.
This paper introduces four techniques developed with the goal of estimating the age of ballpoint inks. These techniques are based on using the microspectrophotometric determination of the rates of color changing in inks as a result of the reaction with chemicals-the older the ink the less the rate (procedure 1); a combination of gas chromatographic (GC) and spectrophotometric methods for determining the masses' ratios 'volatile component/dye component' in ink that decrease with the age of inks (procedure 2); a GC method of determining the extent of extraction of ink volatile components that decreases as ink ages on paper (procedure 3); a thin-layer chromatographic method for determining age changes in resins and other colorless nonvolatile ballpoint ink components: these changes are detected by observing the resulting thin-layer chromatograms under UV illumination and can be evaluated by using scanning densitometry (procedure 4). Suggestions for further work are proposed.
Two procedures for dating ballpoint inks are considered that use gas chromatography (a combination of the technique for determining the extent of extraction of ink volatile components and of the accelerated ageing technique) and densitometric thin-layer chromatography (separation of ink components and evaluation of the resulting chromatograms using a specially developed mass-independent technique that is also a very effective tool for the comparative TLC examination of similarly coloured inks, paints, fibres and other materials of forensic interest). The procedures have been used in many real case situations and the results of the examinations were accepted as conclusive evidence by courts of law.
The headspace profiles of eleven methamphetamine (MA) samples have been analyzed using solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS). Nine of the eleven are illicit MA seizures from the Southwest U.S. border. One sample is methamphetamine base synthesized in the Drug Enforcement Administration (DEA) Southwest Laboratory, and the remaining sample is pharmaceutical-grade methamphetamine hydrochloride that is used to make training aids for drug detecting canines. In addition. volatiles associated with 1-phenyl-2-propanone (P2P), a methamphetamine precursor, have been identified for comparison with those found in methamphetamine seizure and the two reference samples. Eighty-seven different compounds were identified from all the samples, not including simple hydrocarbons and aldehydes. Only seven occur consistently in all seizure samples, and these are: acetic acid, benzaldehyde, acetophenone, P2P, 1-phenyl-1,2-propanedione (P12P), 3-phenyl-3-buten-2-one, 1-chloro-1-phenyl-2-propanone. Dimethyl sulfone, a common cutting agent in methamphetamine. was found in six of the nine seizure materials. When the reference methamphetamine and P2P samples are included, only two compounds are common to all twelve samples, and these are benzaldehyde and P2P. As such, these two compounds are likely candidates for use in a pseudomethamphetamine (PM) formulation, and their effectiveness in eliciting a canine response is being evaluated before actual deployment.
Solid-phase microextraction/gas chromatography-mass spectrometry (SPME/GC-MS) was used to characterize the volatile components associated with U.S. currency, U.S. currency inks, and Canadian currency. Compounds that can be attributed to the ink-curing process include series of straight-chain aldehydes, alkenals, acids, alcohols, and ketones and a series of lactones and 2-alkyl furans. Solvent compounds include naphthenic and paraffinic hydrocarbons with a profile typical of petroleum products, alkyl cyclohexanes, various ethylene glycol alkyl ethers, and traces of chlorinated solvents. Trace levels of 2-phenoxyethanol, a solvent often used in ink formulations, were also detected. Environmental contaminants, those compounds found in circulating currency but not in currency ink, include 2,2'-diethyl-1,1'-biphenyl, methyl benzoate and salicylate, menthol, limonene, dimethyl and diethyl phthalate, and ionol. Not including simple hydrocarbons, over 100 compounds were identified in the headspace of currency-related samples.
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United States Secret Service Forensic Services Division 950 H Street NW Washington
- Additional Information
- Reprint
- M Gerald
- M S F S Laporte
Additional information and reprint requests:
Gerald M. LaPorte, M.S.F.S.
United States Secret Service
Forensic Services Division
950 H Street NW
Washington, DC 20223
E-mail: gerry.laporte@usss.dhs.gov
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- Kr Crawford
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of writing ink. Springfield (IL): Charles C. Thomas, 2003;164.
Proposed standard methods for ink identification
- Jd Kelly
- Aa Cantu
Kelly JD, Cantu AA. Proposed standard methods for ink identification.
J AOAC Int 1975;58:122–25.
Ballpoint ink age-a new approach
- G S Beshanishvily
- E A Trosman
- P B Dallakian
- G P Voskerchian
Beshanishvily GS, Trosman EA, Dallakian PB, Voskerchian GP. Ballpoint ink age-a new approach. Proceedings of the 12th International
Forensic Scientists Symposium; 1990 Oct 15-19;
Advances in the forensic analysis and dating of writing ink. Springfield (IL): Charles C. Thomas
- R L Brunelle
- K R Crawford
Brunelle RL, Crawford KR. Advances in the forensic analysis and dating
of writing ink. Springfield (IL): Charles C. Thomas, 2003;164.
Additional information and reprint requests:
Gerald M. LaPorte, M.S.F.S.
United States Secret Service
Forensic Services Division
950 H Street NW
Washington, DC 20223
E-mail: gerry.laporte@usss.dhs.gov