1
|
Kalinichev AV, Kravchenko AV, Gryazev IP, Kechin AA, Karpukhin OR, Khairullina EM, Kartsova LA, Golovkina AG, Kozynchenko VA, Peshkova MA, Tumkin II. Classification of ballpoint pen inks based on selective extraction and subsequent digital color and cluster analyses. Analyst 2022; 147:3055-3064. [DOI: 10.1039/d2an00482h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Extraction and color analysis coupled with machine learning allows clustering of pen inks and realizing preliminary classification when assessing document age.
Collapse
Affiliation(s)
- Andrey V. Kalinichev
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | | | - Ivan P. Gryazev
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Arseniy A. Kechin
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Oleg R. Karpukhin
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | | | - Liudmila A. Kartsova
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Anna G. Golovkina
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | | | - Maria A. Peshkova
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| | - Ilya I. Tumkin
- Saint Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg 199034, Russia
| |
Collapse
|
2
|
|
3
|
Sabater PQ, Santana OD, Moreno DV. Determining Intersecting Ball-Point Ink Strokes with Different Aging. JOURNAL OF ANALYTICAL CHEMISTRY 2021. [DOI: 10.1134/s1061934821050166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
4
|
Lee LC, Ishak AA, Abdul Hamid N, Ravi Y, Ahmad MA, Ali N. A comparison between univariate and multivariate statistical techniques to determine source of pen inks using ultra-performance liquid chromatography (UPLC) chromatograms. J LIQ CHROMATOGR R T 2020. [DOI: 10.1080/10826076.2020.1858867] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Loong Chuen Lee
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
- Institute of IR4.0 (IIR4.0), Universiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Ab Aziz Ishak
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Nadirah Abdul Hamid
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Yaishnavee Ravi
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Muhamad Adib Ahmad
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
| | - Norazwani Ali
- Forensic Science Program, Center for Diagnostic, Therapeutic and Investigative Studies (CODTIS), Faculty of Health Sciences, Unviersiti Kebangsaan Malaysia, Bangi, Malaysia
| |
Collapse
|
5
|
Salkım İşlek D, İşat E, Cengiz S. Determination of Changes in Crystal Violet and Phenoxyethanol (Dating Ink). J Forensic Sci 2019; 65:661-663. [PMID: 31617942 DOI: 10.1111/1556-4029.14211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Revised: 08/20/2019] [Accepted: 09/16/2019] [Indexed: 11/28/2022]
Abstract
Ink dating is a significant problem in terms of forensic science. Ballpoint pens are generally used as writing tools on the documents. Aging is determination of the changes in dyes and solvents in the composition of ink over time by analytical methods. The evaporation of the solvents from the paper surface is faster than the decomposition process of the dyes. In this study, in 2017, we were asked by the court to determine whether the texts on the suspicious pages of an agenda dated 1996 were written within 2 years or earlier. Phenoxyethanol and dyes were examined in the composition of all suspected ink samples. The results show the determination of both the decomposition process of the dyes and the evaporation process of phenoxyethanol in the aging of the document entries written by ballpoint pen.
Collapse
Affiliation(s)
- Dilek Salkım İşlek
- Institute of Forensic Medicine and Forensic Sciences, Istanbul University-Cerrahpasa, Buyukcekmece Campus, Istanbul, Turkey
| | - Esra İşat
- Cerrahpaşa Faculty of Medicine, Cerrahpaşa Faculty of Medicine, Istanbul University, Fatih Campus, Istanbul, Turkey
| | - Salih Cengiz
- Institute of Forensic Medicine and Forensic Sciences, Istanbul University-Cerrahpasa, Buyukcekmece Campus, Istanbul, Turkey
| |
Collapse
|
6
|
Costa KF, Brand GD, Grobério TS, Braga JW, Zacca JJ. Document ink dye age estimation by direct injection-mass spectrometry and correlation analysis. Microchem J 2019. [DOI: 10.1016/j.microc.2019.04.034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
7
|
Gas chromatography-mass spectrometry and high-performance liquid chromatography-diode array detection for dating of paper ink. J Chromatogr A 2017; 1515:187-195. [PMID: 28807547 DOI: 10.1016/j.chroma.2017.07.093] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 07/28/2017] [Accepted: 07/31/2017] [Indexed: 11/24/2022]
Abstract
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.
Collapse
|
8
|
Sun Q, Luo Y, Zhang Q, Yang X, Xu C. How Much Can a Forensic Laboratory Do to Discriminate Questioned Ink Entries? J Forensic Sci 2016; 61:1116-21. [PMID: 27364295 DOI: 10.1111/1556-4029.13067] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Revised: 09/03/2015] [Accepted: 09/19/2015] [Indexed: 11/29/2022]
Abstract
Questioned document examiners are frequently required to determine whether the questioned ink entries on a document are written with the same ink, either for forged document identification or relative ink dating. How many methods are sufficient to discriminate potentially different inks? In this paper, 18 blue ballpoint inks were first nondestructively examined with a video spectral comparator. The ink entries were subsequently extracted with organic solvents for analysis of the volatile solvents and dyes by GC/MS, TLC, and LC-MS/MS. The 18 ink samples were divided into 10, 9, 12, and 14 categories by these four methods, respectively. With the combined results, there were only two inks that remained indistinguishable, but they were further differentiated by microscopy. Therefore, to achieve effective discrimination of ballpoint ink entries, the authors suggest that a complete examination should include an analysis of their optical features, volatile solvents, and dyes as well as the ink quality.
Collapse
Affiliation(s)
- Qiran Sun
- Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China.,Department of Forensic Science, Shanghai Medical College, Fudan University, No. 138 Yi Xue Yuan Road, Shanghai, 200032, China
| | - Yiwen Luo
- Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China
| | - Qinghua Zhang
- Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China
| | - Xu Yang
- Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China
| | - Che Xu
- Institute of Forensic Science, Ministry of Justice, No. 1347 West Guangfu Road, Shanghai, 200063, China
| |
Collapse
|
9
|
Koenig A, Magnolon S, Weyermann C. A comparative study of ballpoint ink ageing parameters using GC/MS. Forensic Sci Int 2015; 252:93-106. [DOI: 10.1016/j.forsciint.2015.03.027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Revised: 03/09/2015] [Accepted: 03/27/2015] [Indexed: 11/25/2022]
|
10
|
da Silva Ferreira P, Fernandes de Abreu e Silva D, Augusti R, Piccin E. Forensic analysis of ballpoint pen inks using paper spray mass spectrometry. Analyst 2015; 140:811-9. [DOI: 10.1039/c4an01617c] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Paper spray mass spectrometry (PS-MS) is explored as a simple, fast, and effective technique for the forensic analysis of inks in documents.
Collapse
Affiliation(s)
- Priscila da Silva Ferreira
- Departamento de Química
- Instituto de Ciências Exatas
- Universidade Federal de Minas Gerais
- Belo Horizonte 31270-901
- Brazil
| | | | - Rodinei Augusti
- Departamento de Química
- Instituto de Ciências Exatas
- Universidade Federal de Minas Gerais
- Belo Horizonte 31270-901
- Brazil
| | - Evandro Piccin
- Departamento de Química
- Instituto de Ciências Exatas
- Universidade Federal de Minas Gerais
- Belo Horizonte 31270-901
- Brazil
| |
Collapse
|
11
|
Calcerrada M, García-Ruiz C. Analysis of questioned documents: a review. Anal Chim Acta 2014; 853:143-166. [PMID: 25467455 DOI: 10.1016/j.aca.2014.10.057] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 10/24/2014] [Accepted: 10/30/2014] [Indexed: 10/24/2022]
Abstract
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.
Collapse
Affiliation(s)
- Matías Calcerrada
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Multipurpose Building of Chemistry, University of Alcalá, Ctra. Madrid-Barcelona km 33.600, 28871 Alcalá de Henares, Madrid, Spain
| | - Carmen García-Ruiz
- Department of Analytical Chemistry, Physical Chemistry and Chemical Engineering, Multipurpose Building of Chemistry, University of Alcalá, Ctra. Madrid-Barcelona km 33.600, 28871 Alcalá de Henares, Madrid, Spain.
| |
Collapse
|
12
|
Li M, Jia B, Ding L, Hong F, Ouyang Y, Chen R, Zhou S, Chen H, Fang X. Document authentication at molecular levels using desorption atmospheric pressure chemical ionization mass spectrometry imaging. JOURNAL OF MASS SPECTROMETRY : JMS 2013; 48:1042-1049. [PMID: 24078245 DOI: 10.1002/jms.3250] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 06/21/2013] [Accepted: 06/26/2013] [Indexed: 06/02/2023]
Abstract
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.
Collapse
Affiliation(s)
- Ming Li
- National Institute of Metrology, Beijing, 100013, P. R. China
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Senior S, Hamed E, Masoud M, Shehata E. Characterization and Dating of Blue Ballpoint Pen Inks Using Principal Component Analysis of UV-Vis Absorption Spectra, IR Spectroscopy, and HPTLC. J Forensic Sci 2012; 57:1087-93. [DOI: 10.1111/j.1556-4029.2012.02091.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
14
|
Lalli PM, Sanvido GB, Garcia JS, Haddad R, Cosso RG, Maia DRJ, Zacca JJ, Maldaner AO, Eberlin MN. Fingerprinting and aging of ink by easy ambient sonic-spray ionization mass spectrometry. Analyst 2010; 135:745-50. [DOI: 10.1039/b923398a] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
15
|
Wang XF, Yu J, Xie MX, Yao YT, Han J. Identification and dating of the fountain pen ink entries on documents by ion-pairing high-performance liquid chromatography. Forensic Sci Int 2008; 180:43-9. [DOI: 10.1016/j.forsciint.2008.06.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2008] [Revised: 06/03/2008] [Accepted: 06/25/2008] [Indexed: 10/21/2022]
|
16
|
Djozan D, Baheri T, Karimian G, Shahidi M. Forensic discrimination of blue ballpoint pen inks based on thin layer chromatography and image analysis. Forensic Sci Int 2008; 179:199-205. [PMID: 18639403 DOI: 10.1016/j.forsciint.2008.05.013] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 05/18/2008] [Accepted: 05/28/2008] [Indexed: 10/21/2022]
Abstract
This article aims to provide a new and fast method for differentiation of inks on a questioned document. The data acquisition was carried out by designing specific image analysis software for evaluating thin layer chromatograms (TLC-IA). The ink spot was extracted from the document using methanol and separated by TLC using plastic sheet silica gel 60 without fluorescent indicator, and a mixture of ethyl acetate, ethanol, and water (70:35:30, v/v/v) as mobile phase. To discriminate between different pen inks, new software was designed on the basis of intensity profile of red, green, and blue (RGB) characteristic. In practice, after development of chromatogram, the chromatograms were scanned by ordinary office scanner, intensity profiles of RGB characteristics on the development straight of each sample were produced and compared with the mentioned software. RGB profiles of ballpoint inks from various manufacturers showed that the patterns in most cases were distinctly different from each other. This new method allowed discriminating among different pen inks with a high reliability and the discriminating power of 92.8%. Blue ballpoint pen inks of 41 different samples available on the local market were successfully analyzed and discriminated.
Collapse
|
17
|
Ifa DR, Gumaelius LM, Eberlin LS, Manicke NE, Cooks RG. Forensic analysis of inks by imaging desorption electrospray ionization (DESI) mass spectrometry. Analyst 2007; 132:461-7. [PMID: 17471393 DOI: 10.1039/b700236j] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Desorption electrospray ionization mass spectrometry (DESI-MS) is employed in the forensic analysis of documents. Blue ballpoint pen inks applied to ordinary writing paper are examined under ambient conditions without any prior sample preparation. When coupled to an automated moving stage, two-dimensional molecular images are generated. Proof-of-principle experiments include characterization of a simulated forged number and examination of older written records. This application of DESI has advantages over extractive techniques in terms of speed and sample preservation. The effects of the desorbing solvent composition, in this case a mixture of methanol and water, and of flow rate, are evaluated. Results suggest that the solubility of the analyte (dyes Basic Blue 7, Basic Violet 3 and Solvent Blue 26) plays an important role in desorption from the paper surface.
Collapse
Affiliation(s)
- D R Ifa
- Purdue University, Department of Chemistry, West Lafayette, IN 47907, USA
| | | | | | | | | |
Collapse
|
18
|
Liu YZ, Yu J, Xie MX, Liu Y, Han J, Jing TT. Classification and dating of black gel pen ink by ion-pairing high-performance liquid chromatography. J Chromatogr A 2006; 1135:57-64. [PMID: 17028000 DOI: 10.1016/j.chroma.2006.09.031] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Revised: 08/02/2006] [Accepted: 09/15/2006] [Indexed: 11/16/2022]
Abstract
A novel approach for classification and dating of the black gel pen ink entries on document was developed based on ion-pairing high-performance liquid chromatography (IP-HPLC). Ninety-three black gel pens were collected and divided into two groups, dye-based and pigment-based, by preliminary solubility test. The chromatographic conditions for separation of the dye-based black gel pen inks were optimized and the dye components in inks were satisfactorily separated by using 40 mmol/L tetrabutylammonium bromide as ion-pairing reagent. According to the number and the chromatographic retention times of the main dye components, the 50 dye-based inks were categorized into four classes. The inks within a class can be further identified by the percentage of each dye component. The compositional changes of the dye components in the black gel pen ink entries on paper were investigated in light and natural aging conditions and it has been found that the dye components in the ink entries underwent obvious decomposition, and the decomposing extent of the dye components was related to the aging time. The results can provide scientific evidences for dating of the suspicious black gel pen ink entries on documents.
Collapse
Affiliation(s)
- Yi-Zi Liu
- Analytical & Testing Center of Beijing Normal University, Beijing 100875, China
| | | | | | | | | | | |
Collapse
|
19
|
Liu YZ, Yu J, Xie MX, Chen Y, Jiang GY, Gao Y. Studies on the degradation of blue gel pen dyes by ion-pairing high performance liquid chromatography and electrospray tandem mass spectrometry. J Chromatogr A 2006; 1125:95-103. [PMID: 16759660 DOI: 10.1016/j.chroma.2006.05.034] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2006] [Revised: 05/12/2006] [Accepted: 05/15/2006] [Indexed: 11/21/2022]
Abstract
Ion-pairing high performance liquid chromatography (IP-HPLC) was utilized to monitor the composition changes of blue gel pen ink entries on paper stored in different light conditions and natural environment. The chromatographic conditions were optimized by comparing the separation efficiencies of the blue gel pen inks using a series of ion-pairing reagents, including ammonium carbonate, ammonium acetate, triethylamine acetate, tributylamine acetate, tetrabutylammonium bromide and dihexylammonium acetate. It has been found that tributylamine acetate was a suitable ion-pairing reagent for separation of the inks on the common C18 column. The analysis results of the ink entries on paper in different aging conditions showed that the tendency of composition change in natural aging condition was similar with those in fluorescent light and UV light conditions, respectively. One main component dye of the blue gel pen ink, Acid Blue 9, and its degradation products were identified by ion-pairing high performance liquid chromatography coupled with electrospray tandem mass spectrometry. The results showed that the main degradation products originated from the Acid Blue 9. It gave a reasonable explanation for the changing rules of the relative content of the dyes in the blue gel pen ink. The results obtained can provide scientific evidences for dating of the blue gel pen ink entries on documents.
Collapse
Affiliation(s)
- Yi-Zi Liu
- Analytical & Testing Center, Beijing Normal University, Beijing 100875, PR China
| | | | | | | | | | | |
Collapse
|
20
|
Petrick LM, Wilson TA, Ronald Fawcett W. High-Performance Liquid Chromatography-Ultraviolet-Visible Spectroscopy-Electrospray Ionization Mass Spectrometry Method for Acrylic and Polyester Forensic Fiber Dye Analysis*. J Forensic Sci 2006; 51:771-9. [PMID: 16882218 DOI: 10.1111/j.1556-4029.2006.00155.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A critical point of comparison between a fiber collected from a crime scene and a fiber from a known source is the color. Fiber dye analysis using thin-layer chromatography or ultraviolet (UV)-visible (Vis) microspectrophotometry provides useful, although limited, data for comparison. High-performance liquid chromatography-electrospray ionization mass spectrometry (LC/MS) overcomes these limitations by integrating chromatography, ultraviolet-visible spectroscopy, and mass spectrometry into a single instrument. In order to evaluate the applicability of the LC/MS to forensic fiber dye analysis, a multi-stage chromatographic method using acidified water and acidified acetonitrile was developed that separated and identified a mixture of 15 basic and 13 disperse dye standards. The LC/MS also detected and analyzed dyes extracted from individual 0.5 cm acrylic and polyester fibers, demonstrating its applicability to this type of analysis. With regard to the analysis of disperse dyes in polyester fibers, the replacement of pyridine with acetonitrile in the extraction system allowed direct injection of the extracts into the LC/MS. The advantage of the LC/MS over other instrumental methods of textile dye analysis is demonstrated by the analysis and differentiation of three black acrylic fibers: two fibers had similar UV-Vis spectra but were differentiated with chromatography and two had similar UV-Vis spectra and chromatograms but were differentiated using the mass spectrometer.
Collapse
Affiliation(s)
- Lauren M Petrick
- Chemistry Department, University of California at Davis, One Shields Avenue, Davis, CA 95616, USA
| | | | | |
Collapse
|
21
|
Affiliation(s)
- T A Brettell
- Office of Forensic Sciences, New Jersey State Police, New Jersey Forensic Science and Technology Complex, 1200 Negron Road, Horizon Center, Hamilton, New Jersey 08691, USA
| | | | | |
Collapse
|