Forensic Chemistry最新文献

{"title":"Spectroscopy and chemometrics for differentiation of sex in human head hair fibers","authors":"Drew Mueller ,&nbsp;Alexis Hecker ,&nbsp;John V. Goodpaster","doi":"10.1016/j.forc.2024.100632","DOIUrl":"10.1016/j.forc.2024.100632","url":null,"abstract":"<div><div>Human hair is one of the most common pieces of evidence in forensics, however, it lacks a non-destructive, time-efficient, methodology for qualitative information. With the already well-established method for fiber analysis in spectroscopy and the common presence of Fourier Transform Infrared (FTIR) and microspectrophotometry (MSP) instrumentation in forensics, this study proposes chemometric approach to differentiate hair fibers on the sex assigned at birth. The IR and MSP hair sample spectra from different sexes were collected and, following spectral pre-treatment and mid-level data fusion, were used to calibrate a neural network model with 99.6% accuracy and 99.4% validation accuracy through an external validation dataset. This approach provides a robust model with significant qualitative information for forensic investigations that can be easily applied in forensic labs across the world. These results represent a rather small population size which would need to be expanded for real-world forensic applications.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100632"},"PeriodicalIF":2.6,"publicationDate":"2024-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Non-targeted detection of cathinones by high-resolution mass spectrometry based on their fragmentation pattern prediction. Application to pyrrolidine analogues in a hair case of PV8","authors":"José Manuel Matey ,&nbsp;Luis Manuel Menéndez-Quintanal ,&nbsp;Félix Zapata ,&nbsp;Gemma Montalvo ,&nbsp;Carmen García-Ruiz","doi":"10.1016/j.forc.2024.100630","DOIUrl":"10.1016/j.forc.2024.100630","url":null,"abstract":"<div><div>Cathinones (<em>i.e.</em>, beta-keto phenyl ethyl amines) are one of the most numerous and widespread categories among new psychoactive substances. A selective methodology based on diagnostic fragment criteria using high resolution mass spectrometry, is comprehensively evaluated. Based on the different fragmentation spectra that have been published in public databases such as mzCloud (<span><span>www.mzcloud.org</span><svg><path></path></svg></span>) and HighResNPS (<span><span>www.highresnps.com</span><svg><path></path></svg></span>), we have coded and evaluated the different analogues and substituents in the benzyl position (R₁), in the α-alkyl chain (R₃) and N-alkyl analogues (R₄ and R₅) for existing cathinones, especially focusing on tertiary amines containing a pyrrolidine ring.<!--> <!-->The proposed fragmentation pattern allows the prediction of the expected fragments for each type of cathinone. The detection of selective diagnostic fragments ions supports the identification among different cathinone analogues. In this work, the proposed methodology is extended from the primary data to the generation of peridate, through their conceptualization and proposed SQL searches. A real case of pyrrolidine cathinones not yet present on the illicit market or recently introduced is used as an example. Using this strategy and specific software, we were able to detect cathinones such as α-pyrrolidinoheptaphenone (PV8) in hair.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100630"},"PeriodicalIF":2.6,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico created fire debris data for Machine learning","authors":"Michael E. Sigman ,&nbsp;Mary R. Williams ,&nbsp;Larry Tang ,&nbsp;Slun Booppasiri ,&nbsp;Nikhil Prakash","doi":"10.1016/j.forc.2024.100633","DOIUrl":"10.1016/j.forc.2024.100633","url":null,"abstract":"<div><div>Attacking complex forensic problems, such as the classification of fire debris data as positive or negative for ignitable liquid residue (ILR), requires large amounts of training data if machine learning approaches are to be successful. This work examines the in-silico preparation of computed fire debris data for training a machine learning method to classify gas chromatography – mass spectrometry (GC–MS) data as positive or negative for ILR, and reports the outcome of validation tests on a set of laboratory-generated fire debris samples with known ground truth. A set of 240,000 total ion chromatograms (TIC) and total ion spectra (TIS) for fire debris (FD) samples were calculated in silico (IS). The IS FD sample set was balanced with 50% of the samples containing ignitable liquid residue (ILR) and substrate pyrolysis (SUB) contributions. The remaining 50% contained only SUB components. The ignitable liquids incorporated into the samples containing ILR were digitally evaporated to simulate weathering observed in experimental fire debris. The IS FD sample TIS were treated by principal component analysis (PCA) with centering and variance scaling and retaining 90% of the variance. A set of 1,117 experimental FD samples were projected into the IS FD PCA model. The recovered experimental FD TIS were compared to the TIS before projection by calculating the residual mean squared error (RMSE) for each sample as a test of the IS FD samples representation of experimental samples. The range of the RMSE was [ 0.012, 0.127] and the median RMSE was 0.029. Experimental FD samples where the recovered TIS had the larger RMSE values were not well-represented by the IS FD samples. The IS FD samples were randomly split into balanced sets for machine learning (ML) training (90%) and validation (10%). An XGBoost ML method, trained on the IS FD training data, was validated on the testing IS FD data, giving a receiver operating curve (ROC) with area under the curve (AUC) of 0.978. Validation of the model against the experimental FD data gave a lower ROC AUC of 0.845. Limiting the experimental data to samples in the lowest quadrant of RMSE values increased the ROC AUC to 0.90.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100633"},"PeriodicalIF":2.6,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DART-HRMS analysis as a screening method for hallucinogenic mushrooms","authors":"Vanessa Braga Galhego,&nbsp;Raquel Capilla Loureiro Alves de Santana,&nbsp;Cecília de Andrade Bhering,&nbsp;Ananda da Silva Antonio,&nbsp;Gabriela Vanini","doi":"10.1016/j.forc.2024.100629","DOIUrl":"10.1016/j.forc.2024.100629","url":null,"abstract":"<div><div>The global drug abuse scene is dynamic. After COVID-19 psilocin-containing mushrooms (PCM) reemerged in the international scenario. To identify illicit drugs, multiple analytical methods must be employed including triage (e.g. colorimetric test) and confirmatory tests (e.g. GC–MS). In addition, in many cases, only samples that give positive results in the triage method are taken to the confirmatory ones. However, colorimetric methods have several drawbacks in the analysis of complex unusual samples, such as the PCM, which can produce false-negative results. This study evaluated the feasibility of the ambient ionization technique direct analysis in real time – high-resolution mass spectrometry (DART-HRMS) as a triage method for the identification of PCM seized samples. A psilocin standard, edible mushrooms, and 5 seized PCM samples were used to establish the DART-HRMS instrumental setup required for psilocin analysis. The developed DART-HRMS method was compared to the triage method recommended for PCM screening analysis (Erlich’s test). While the analysis of psilocin solutions applied 300 V at the DART grid and carrier gas at 150 °C, the analysis of solid samples applied 300 V and 375 °C. All seized PCM samples presented negative results in Erlich’s test, while all of them were positive for psilocin by DART-HRMS. Based on the quality of the HRMS data it was possible to confirm that Erlich’s test results were false-negative for the seized samples. DART-HRMS presents itself as a fast, reliable, and trustworthy triage method for the qualitative identification of raw hallucinogenic mushrooms for criminal investigation.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100629"},"PeriodicalIF":2.6,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determining extent and distribution of methamphetamine in cars: Air vs. surface vs. fabrics","authors":"Gemma L. Kerry ,&nbsp;Kirstin E. Ross ,&nbsp;G. Stewart Walker ,&nbsp;Jackie Wright","doi":"10.1016/j.forc.2024.100628","DOIUrl":"10.1016/j.forc.2024.100628","url":null,"abstract":"<div><div>Methamphetamine can be manufactured or smoked in vehicles resulting in contamination. In addition, the transportation of drugs between place of manufacture and distribution can lead to contamination. Subsequent passengers or drivers of contaminated vehicles could be exposed to thirdhand drugs. Individuals exposed to thirdhand contamination have shown adverse health symptoms including respiratory problems, headaches, and behavioural and cognitive issues. Therefore, it is important to determine the overall methamphetamine contamination extent of cars to protect public health. This study was undertaken to determine the extent and distribution of contamination on surfaces, in air and from porous materials in two cars that tested positive for methamphetamine. Air sampling was performed in two cars using two sorbent tube types, followed by solvent desorption, and analysis using liquid chromatography tandem mass spectrometry (LC–MS/MS). Additionally, surface wipe sampling and bulk material sampling was performed for one of the contaminated cars that was going to be destroyed. These results demonstrated that methamphetamine can be detected in air, on the surfaces of non-porous and porous materials and from within porous materials. Results also demonstrated that methamphetamine was still detected from a second, third and fourth wipe sampling event of a plastic surface, indicating that there is a necessity for further research on testing and remediation in cars.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100628"},"PeriodicalIF":2.6,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differentiated factor expression by chemical class in the concentration of ignitable liquid residue by dynamic vapor microextraction","authors":"Mary Gregg ,&nbsp;Jennifer Berry ,&nbsp;Kavita Jeerage","doi":"10.1016/j.forc.2024.100631","DOIUrl":"10.1016/j.forc.2024.100631","url":null,"abstract":"<div><div>Ignitable liquids (IL) are complex mixtures whose chromatographic profiles may vary considerably across chemical compound classes. Dynamic vapor microextraction (DVME) is an emerging technique with potential application for extracting and concentrating IL from fire debris. A previous study assessed the effects of 11 instrumental and debris factors on DVME performance by collecting chromatographic data from a designed experiment, but did not investigate whether factor effects had differential expression within individual chemical classes. In this study, that experimental data is reanalyzed to assess factor effects individually in each of five chemical classes relevant to IL identification (alkanes, cycloalkanes &amp; alkenes, aromatic-alkylbenzenes, indanes, and polynuclear aromatics), and effects are compared to the results previously reported from the original analysis. Two new instrument settings (capillary vapor trap coating and temperature) are found to have significant class-specific effects, providing additional avenues of improving DVME performance, while the effect of collection volume is found to be discordant in one class (alkane) compared to all others. Effects from uncontrollable debris factors on DVME performance are also found to be partially mitigated in certain classes through optimal instrument settings, though “optimal” may depend on the sample being analyzed. This analysis offers new insight into DVME optimization and robustness, and provides a discussion on how experimental conclusions drawn from aggregate chromatographic data, without consideration of class-specific effects, may be incomplete.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100631"},"PeriodicalIF":2.6,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and application of ion chromatography for analyzing explosive residues in criminal Investigations: A study of ions in ATM and residues from emulsion and pipe bomb explosions","authors":"Paula Ribeiro Junho ,&nbsp;Yuri Machado ,&nbsp;Ricardo M. Orlando","doi":"10.1016/j.forc.2024.100627","DOIUrl":"10.1016/j.forc.2024.100627","url":null,"abstract":"<div><div>The criminal use of explosives, particularly in attacks on automated teller machines (ATMs), remains prevalent in many countries, including Brazil. Ion chromatography is a leading technique for analyzing residues from post-blast materials. In this study, we developed methods to analyze 8 cations and 18 anions using suppressed ion chromatography with conductivity detection. Different collection materials and procedures were also evaluated. The chromatographic methods were assessed using various metrics and demonstrated analytical performance in line with existing literature. The methods were applied to determine the ion content in three brands of swabs commonly used for sample collection. Initial results showed significant levels of various ions, which were largely removed through a simple washing process. Our findings indicate that certain swab brands of the same type perfomed better than others, and the preferred swab was used in recovery studies. We concluded that using pre-washed swabs moistened with water results in higher recovery rates and reduces interference. An ion stability test conducted over 12 weeks suggested that swabs should be stored in a refrigerator and ideally analyzed within the first week after collection to minimize analyte loss. Background samples collected from an ATM did not contain ion levels that could be mistaken for those from explosive residues. The chromatographic and sampling methods were applied to real samples from different types of explosive residues, including those from an emulsion-based explosive and a pipe bomb containing black powder substitute. The analysis successfully identified key ions: NO3⁻ and NH₄⁺ in the emulsion, and ClO₄⁻ and K⁺ in the black powder substitute, allowing us to differentiate the explosives used. This work introduces significant methodological advancements in the analysis of explosive residues, particularly through the development of an extensive chromatographic method, the mitigation of ion interferences, improved sample preservation protocols, and the successful application to real-world scenarios, distinguishing emulsion-based explosives from gunpowder.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100627"},"PeriodicalIF":2.6,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Forensic characterization of spontaneous acetone peroxide formation from consumer-aged 2-propanol","authors":"Ryan M. Bain ,&nbsp;Andrew Hawkins ,&nbsp;Steve Linehan ,&nbsp;John R. Stutzman","doi":"10.1016/j.forc.2024.100623","DOIUrl":"10.1016/j.forc.2024.100623","url":null,"abstract":"<div><div>Numerous instances of well-aged consumer-grade 2-propanol (isopropanol) containing solid primary explosive material have been reported and turned over to the authorities. Herein, one such sample that was turned over to the Bureau of Alcohol, Tobacco, Firearms and Explosives has been analytically characterized to understand the solid primary explosive material as well as the liquid composition for forensic purposes. Upon examination by several analytical methodologies, the liquid phase of the sample contained isopropanol with measurable amounts of species indicative of isopropanol degradation and precursors to triacetone triperoxide. These species included acetone, methanol, acetic acid, isopropyl acetate, hydroxy-propanone, linear acetone peroxides, several atypical linear acetone peroxides species, and cyclic acetone peroxides (<em>e.g.,</em> triacetone triperoxide). The solid material in the container was predominately triacetone triperoxide as well as diacetone diperoxide and tetraacetone tetraperoxide. Microscopic properties and x-ray powder diffractograms of the solid material recovered from the aged isopropanol differed from traditionally synthesized triacetone triperoxide. This comprehensive analysis serves as a reference and aid in analysis for forensic laboratories when alleged samples of spontaneously formed triacetone triperoxide are encountered.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100623"},"PeriodicalIF":2.6,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142746332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of GC–MS retention index in forensic routine","authors":"Ettore Ferrari Júnior ,&nbsp;Luisa Pereira e Ferreira ,&nbsp;Rogério Araújo Lordeiro ,&nbsp;Yuri Machado","doi":"10.1016/j.forc.2024.100622","DOIUrl":"10.1016/j.forc.2024.100622","url":null,"abstract":"<div><div>Gas chromatography–mass spectrometry (GC–MS) is widely used for the identification of substances of forensic interest, but it faces challenges due to the vast diversity of available drugs. In this context, the use of the linear retention index (LRI) can help overcome difficulties associated with the identification of a large number of substances, as it is less susceptible to variations in experimental conditions compared to retention time (RT). Building an LRI database allows rapid and simultaneous identification of several compounds, including new and structurally similar substances, thus standardizing analytical identification. This study aimed to evaluate the use of the retention index (RI) in both intralaboratory and interlaboratory forensic routines. Over a 50-week period on the same GC–MS system, RI values were effectively adjusted by reinjecting an n-alkane mix after maintenance that required vacuum breaks, updating the retention times of each substance evaluated (benzocaine, caffeine, cocaine and flunitrazepam). Interlaboratory reproducibility was evaluated between two forensic laboratories using up to 104 analytes. Two oven temperature programs, three GC brands and two analytical columns were evaluated. Under the same analytical conditions, the ΔRI was ≤10 index units (i.u.) for 103 substances, with testosterone enanthate showing a ΔRI = 11 i.u.. The proposed method proved to be reproducible and selective, and the use of RI has demonstrated accuracy as a complementary technique for identifying a wide range of analytes. Furthermore, the sharing of an RI database can strengthen the analytical routine, being a way to quickly obtain information on the identification of new drugs.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"41 ","pages":"Article 100622"},"PeriodicalIF":2.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved differentiation of NPS analogs through the application of chemometric methods to GC-solid deposition-FTIR spectra","authors":"Jennifer L. Bonetti ,&nbsp;Ruben F. Kranenburg ,&nbsp;Stephen Hokanson ,&nbsp;Matthew Pothier ,&nbsp;Saer Samanipour ,&nbsp;Arian C. van Asten","doi":"10.1016/j.forc.2024.100619","DOIUrl":"10.1016/j.forc.2024.100619","url":null,"abstract":"<div><div>Novel psychoactive substances pose a significant analytical challenge for forensic laboratories. Gas Chromatography with Infrared Spectroscopy (GC-IR) is typically presented as producing visually distinct spectra. However, this is not the case for all compounds. In this study, we showcase three synthetic cathinone analogs (methylone, N-ethylpentylone, and pentylone) which produce extremely visually similar solid state IR spectra.</div><div>A primary dataset of these analogs was generated at the Amsterdam Police Laboratory. Libraries were created using two different sample preparation methods. The same compounds were also analyzed at the Virginia Department of Forensic Science (DFS). It was observed that changes in either instrument or sample preparation were enough to pose challenges to both the visual assessment and a library matching algorithm. Additionally, week-to-week variation was observed within the primary dataset. Principal Component Analysis (PCA) in combination with mahalanobis distances for objective comparison was assessed. A leave-one-sample-out cross validation accurately identified 100% of the samples in the primary dataset.</div><div>This study shows how the application of chemometrics to spectral GC-IR data can substantiate the instrument’s differentiation capabilities and provide valuable objective support for a compound identification. In addition, limitations in the consistency of GC-IR spectra over time and across instruments and sample preparation methods were observed which could affect how the forensic community utilizes these techniques. Specifically, this study shows that shared GC-IR libraries might pose selectivity limitations. Therefore, laboratories must exercise caution if shared/generic GC-IR libraries are utilized for casework, and it is recommended that instrument and solvent specific libraries are generated.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"41 ","pages":"Article 100619"},"PeriodicalIF":2.6,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142704612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}