Forensic Chemistry最新文献

{"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":"2025-03-01","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":"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":"2025-03-01","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":"Modification of screen-printed electrodes using gold nanostructures for SERS detection of low explosives","authors":"Thinnapong Wongpakdee ,&nbsp;Duangjai Nacapricha ,&nbsp;Bruce McCord","doi":"10.1016/j.forc.2024.100636","DOIUrl":"10.1016/j.forc.2024.100636","url":null,"abstract":"<div><div>This study explores a novel application of surface-enhanced Raman spectroscopy (SERS) as a highly sensitive analytical tool for forensic analysis. We utilized a screen-printed gold electrode (SPGE) as a SERS active material, integrated with a portable Raman instrument for the rapid detection of low explosives. To enhance sensitivity while ensuring ease of handling, we conducted ex situ electrodeposition of gold nanostructures on the SPGE surface prior to analysis. The targeted molecules, comprising potassium nitrate (KNO₃), potassium perchlorate (KClO₄), sodium benzoate (C₆H₅COONa), diphenylamine (DPA) with its nitro derivatives, methyl centralite (MC) and ethyl centralite (EC), were studied using the proposed methodology. The developed system successfully provided distinctive SERS spectra fingerprints for low explosives (black powder, black powder substitutes, and smokeless powder) within seconds of analysis time. This approach holds promise for rapid, efficient, and accurate forensic analysis in real-world scenarios.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100636"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145515","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":"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":"2025-03-01","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":"Characterizing nitrocellulose by nitration degree and molecular weight: A user-friendly yet powerful forensic comparison method for smokeless powders","authors":"Rick S. van den Hurk ,&nbsp;Ids B. Lemmink ,&nbsp;Jade R. van Schaik ,&nbsp;Annemieke W.C. Hulsbergen ,&nbsp;Ron A.H. Peters ,&nbsp;Bob W.J. Pirok ,&nbsp;Arian C. van Asten","doi":"10.1016/j.forc.2024.100637","DOIUrl":"10.1016/j.forc.2024.100637","url":null,"abstract":"<div><div>Smokeless powders (SPs) are commonly used as propellant for ammunition but are also used as explosive component in improvised explosive devices. Therefore, its chemical characterization is of high importance when reporting forensic explosives investigations to a court of law. While conventional analytical strategies focus on the characterization of the additives in SPs, only few methods consider the main explosive component in SP, nitrocellulose (NC).</div><div>In this study, a user-friendly analytical method was developed for characterizing NC in SPs. The method employs size-exclusion chromatography combined with ultraviolet (UV) and refractive index (RI) detection. Through the size separation, the SP additives are separated from the polymeric NC because of their lower molecular weight. The novel part of the system lies in the simultaneous measurement of the molecular-weight distribution (MWD) and the nitration degree, thus boosting the discriminating power obtained from a single analysis. The combined use of two detectors enables a highly specific analysis, because the ratio between the UV and RI signal intensities is directly correlated with the nitration degree of NC. Characterizing the nitrocellulose demonstrated high discriminating powers of 98.95 % for the MWD and 92.65 % for the nitration degree using a set of 20 SP products. Combined, all sample pairs in our sample set could be distinguished.</div><div>The proposed method is not limited to product classification that is obtained from additive profiles, and potentially offers individualization at batch level. This method provides high discriminating power while requiring little financial investment with regards to instrumentation and maintenance.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100637"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145514","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":"Quantitative analysis of cannabinoids by zone heat-assisted DART-MS with in-situ flash derivatization","authors":"Wen Dong ,&nbsp;Junxiaohan Yuan ,&nbsp;Xin Yang ,&nbsp;Ning Zhang ,&nbsp;Mengliang Zhang","doi":"10.1016/j.forc.2025.100641","DOIUrl":"10.1016/j.forc.2025.100641","url":null,"abstract":"<div><div>Accurate quantitation of cannabinoids, particularly Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), is essential for regulatory compliance, forensic investigations, and cannabis product development. Traditional methods, such as liquid chromatography (LC) and gas chromatography (GC) coupled with mass spectrometry, provide reliable results but are time-consuming and resource-intensive. This study introduces a rapid and high-throughput analytical method using zone heat-assisted direct analysis in real time mass spectrometry (DART-MS) combined with in-situ flash derivatization. The method employs trimethylphenylammonium hydroxide (TMPAH) for efficient derivatization, allowing for the differentiation of THC, CBD, and their acidic precursors, Δ9-tetrahydrocannabinolic acid (THCA) and cannabidiolic acid (CBDA). A custom heated transfer zone was implemented to enhance derivatization efficiency and reduce carryover effects. The method was optimized for reagent concentration and gas stream temperature, achieving high specificity by minimizing interference from isomeric cannabinoids. Validation studies demonstrate good accuracy (relative error within ±15.9 %) and precision (relative standard deviation ≤15 %), with limits of quantitation of 7.5 µg/mL for THC/CBD and 0.5 µg/mL for THCA/CBDA. Comparative analysis of cannabis samples showed a strong correlation with reference LC/MS results, highlighting the reliability of the proposed method. DART-MS offers a significant time advantage, requiring only 10 s per analysis, making it a promising tool for high-throughput screening of cannabis samples in forensic laboratories.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100641"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144617","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":"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":"2025-03-01","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":"The comparison of volatile organic compound profiles between human and non-human bones and its application to human remains detection dogs","authors":"Marissa Tsontakis ,&nbsp;Darshil Patel ,&nbsp;Frédérique Ouimet ,&nbsp;Clifford Samson ,&nbsp;Wesley S Burr ,&nbsp;Shari L. Forbes","doi":"10.1016/j.forc.2025.100642","DOIUrl":"10.1016/j.forc.2025.100642","url":null,"abstract":"<div><div>Human Remains Detection (HRD) dogs are specifically trained to aid law enforcement agencies in search operations for deceased victims. Their olfactory sensitivity and specificity highlight the importance of choosing target odor sources for HRD training. While HRD dogs rely on olfactory cues to locate human remains, it is important to identify which volatile organic compounds (VOCs) they are alerting to among those released during the various stages of the human decomposition process. In this study, VOC profiles from human and non-human bones were collected and analyzed using thermal desorption coupled to comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (TD-GC × GC-TOFMS). The non-human decomposition VOC profiles were compared to human VOC profiles obtained from sections of amputated human limbs used as HRD training aids. These limb sections were previously decomposed to the dry remains/skeletonization stage. The olfactory responses of HRD dogs in the presence of these training aids and non-human remains were subsequently investigated with results demonstrating their capability in distinguishing human from non-human remains. Highlighting the differences in VOC profiles between human and non-human decomposition may help to enhance the sensitivity of HRD dogs to human remains while recognizing the importance of using human cadaveric material for training purposes.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100642"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143144618","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":"Evaluation of the incorporation of µ-XRF SDD systems in analytical workflows of black electrical tapes","authors":"Lacey Leatherland ,&nbsp;Ruthmara Corzo ,&nbsp;Charlotte Vogler ,&nbsp;Addio Fiordigigli ,&nbsp;Cedric Neumann ,&nbsp;Tatiana Trejos","doi":"10.1016/j.forc.2024.100638","DOIUrl":"10.1016/j.forc.2024.100638","url":null,"abstract":"<div><div>Micro-X-ray Fluorescence Spectrometry (µ-XRF) is a technique widely adopted in forensic laboratories that has recently experienced a significant improvement with silicon drift detectors (SDDs). However, the research lag in this area has not caught up with the emergent instrumental modernization. This study expands the current body of knowledge by addressing this gap and evaluating the optimal workflow to incorporate µ-XRF SDD methods in electrical tape examinations. The experimental design evaluates sample handling and chemical data interpretation when the tape needs to undergo latent fingerprint development. The dataset includes contemporary electrical tape from 45 rolls produced in four countries, seven manufacturers, ten brands, and various quality grades (high, medium, low); ten sections are sampled per roll. Pairwise comparisons (990) evaluate between-source discrimination and false inclusions. Also, the set contains five same-source rolls with 20 sections per roll to evaluate within-source variability and false exclusions (950 pairwise comparisons). Samples are examined by µ-XRF SDDs and three other conventional methods. Performance rates are reported for each technique alone and when used together to evaluate optimal combinations and analytical sequences. Due to high discrimination and classification abilities, it is recommended that µ-XRF analysis moves to the forefront of the analytical scheme after microscopic examination to optimize turnaround times, costs, and resources. Also, the study utilizes elemental ratio comparison intervals and quantitative similarity metrics that offer complementary information to reduce subjectivity in XRF spectral comparisons. The findings of this study are anticipated to assist forensic laboratories with improved protocols.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100638"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145517","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":"GC-VUV spectroscopy of synthetic cannabinoid isomers, diastereomers and homologs: Increasing differentiation by derivative spectral processing","authors":"Annika Dombrowski,&nbsp;Diana Le,&nbsp;Ira S. Lurie","doi":"10.1016/j.forc.2024.100635","DOIUrl":"10.1016/j.forc.2024.100635","url":null,"abstract":"<div><div>The increased prevalence of synthetic drugs has led to a rise in isomeric compounds on the market, resulting in a need for analysis techniques capable of distinguishing between these analytes. Previous research has investigated the potential of gas chromatography – vacuum ultraviolet spectroscopy (GC-VUV) for this purpose, demonstrating its complimentary nature to the more traditional gas chromatography – mass spectrometry (GC–MS). This work reinforces the value of GC-VUV and demonstrates its potential for GC–MS-like specificity through the application of derivative analysis to VUV spectra. Seventeen JWH 018 positional isomers and six diastereomers, including two homologs, were analyzed by GC-VUV and derivative analysis. Library searches and principal component analysis (PCA) were used to compare the specificity of non-, first, and second derivative spectra. Derivative analysis was found to increase specificity in library searches by lowering the frequency of false hits, and in PCA by improving separation and clustering. This demonstrates the potential value of GC-VUV analysis in general, as well as of the implementation of derivative analysis for isomer identification.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"42 ","pages":"Article 100635"},"PeriodicalIF":2.6,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145518","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}