Forensic Chemistry最新文献

SPME–GC–MS analysis of fire debris: assessing sample transfer viability for automated analysis and the influence of sooty materials 火灾碎片的SPME-GC-MS分析：评估自动分析的样品转移可行性和煤烟材料的影响

IF 2.2 3区医学

Forensic Chemistry Pub Date : 2025-07-28 DOI: 10.1016/j.forc.2025.100688

Lúcio Paulo Lima Logrado , Jez Willian Batista Braga

{"title":"SPME–GC–MS analysis of fire debris: assessing sample transfer viability for automated analysis and the influence of sooty materials","authors":"Lúcio Paulo Lima Logrado , Jez Willian Batista Braga","doi":"10.1016/j.forc.2025.100688","DOIUrl":"10.1016/j.forc.2025.100688","url":null,"abstract":"<div><div>Abstract</div><div>Arson investigation poses unique challenges in forensic science due to the destructive nature of fires, which can compromise physical evidence. It is one of the most challenging areas of forensic chemistry, frequently applied to identify flammable liquids in fire debris. SPME–GC–MS is one of the most applied techniques for this purpose. Automated SPME–GC–MS systems offer various advantages over manual versions, such as increased efficiency, reproducibility, precision, and reduced analysis time. However, samples are often not sent to the laboratory in vials appropriate for automated SPME, raising questions about the feasibility of transferring them to these headspace vials in the laboratory to take advantage of this automation. Another significant issue with this analytical technique is how highly adsorbent materials in the sample, such as sooty materials, can hinder SPME analyses by affecting analyte desorption and subsequent detection. This study addresses these crucial questions by evaluating sample losses and assessing the impact of sooty materials on results. It demonstrates that transferring fire debris samples is feasible, with minimal impact on chromatographic profiles even for unburned gasoline when exposed to the atmosphere for short periods. Burned gasoline can still be identified, despite some losses, even after more than 24 h. The study also demonstrated that the presence of sooty material can hinder analyte detection in direct SPME analysis, but this can be mitigated using nonpolar solvent extractions followed by analyses of the dried extract using the same analytical technique.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100688"},"PeriodicalIF":2.2,"publicationDate":"2025-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144724699","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}

引用次数: 0

2D NMR detection and quantification of heroin in a street sample 街头样本中海洛因的二维核磁共振检测与定量

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-07-20 DOI: 10.1016/j.forc.2025.100687

Kathryn M. James , Samantha V. Boni , Kayla Gratton , Mallory J. Stopko , Michael Cipoletti , Timothy Gilbert , Alexander K. Goroncy , Takashi L. Suyama

{"title":"2D NMR detection and quantification of heroin in a street sample","authors":"Kathryn M. James , Samantha V. Boni , Kayla Gratton , Mallory J. Stopko , Michael Cipoletti , Timothy Gilbert , Alexander K. Goroncy , Takashi L. Suyama","doi":"10.1016/j.forc.2025.100687","DOIUrl":"10.1016/j.forc.2025.100687","url":null,"abstract":"<div><div>Two-dimensional nuclear magnetic resonance (2D NMR) spectroscopy was evaluated for the identification and quantification of compounds in an unknown street drug sample. Using 2D COSY and HSQC techniques, heroin was successfully quantified, and the presence of 6-monoacetylmorphine (6-MAM), xylazine, and caffeine was confirmed through partial structural elucidation. These methods demonstrated the ability to differentiate structurally similar opioid analogues without reliance on reference library databases. While gas chromatography–mass spectrometry (GC–MS) remains the standard in forensic laboratories, it has limitations in de novo structural analysis and in detecting emerging analogues absent from spectral libraries. In this study, heroin and fentanyl were quantified in both simulated and actual street samples at concentrations ranging from 0.97 to 1.80 mg/mL, with errors between 0 % and 34 % using a 400 MHz NMR instrument. A benchtop 60 MHz NMR system also detected and quantified 56 mg/mL of heroin with a 24 % error in a simulated sample. These findings support the complementary role of 2D NMR spectroscopy in forensic drug analysis in light of the opioid epidemic and the evolving drug market.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100687"},"PeriodicalIF":2.6,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144702415","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}

引用次数: 0

Analytical identification of ergot alkaloids in Ipomoea species: Resolving historical, forensic, and legal ambiguities 麦角生物碱的分析鉴定：解决历史、法医和法律上的歧义

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-07-18 DOI: 10.1016/j.forc.2025.100686

Enrico Greco , Andrea Farci , Fiorella Florian , Alberto Pallavicini , Alessandro Miani , Pierluigi Barbieri , Giorgio Samorini

{"title":"Analytical identification of ergot alkaloids in Ipomoea species: Resolving historical, forensic, and legal ambiguities","authors":"Enrico Greco , Andrea Farci , Fiorella Florian , Alberto Pallavicini , Alessandro Miani , Pierluigi Barbieri , Giorgio Samorini","doi":"10.1016/j.forc.2025.100686","DOIUrl":"10.1016/j.forc.2025.100686","url":null,"abstract":"<div><div>This study addresses the longstanding taxonomic confusion between two plant species within the Convolvulaceae family: <em>Ipomoea tricolor</em> Cav. and <em>Ipomoea violacea</em> L., historically mistaken as synonymous. Employing advanced analytical methods including LC-MS/MS (Orbitrap), coupled with genetic barcoding, we provide clear biochemical differentiation between the two species based on the presence or absence of psychoactive ergoline alkaloids. Our analyses confirm that seeds of <em>I. tricolor</em> consistently contain significant levels of psychoactive compounds structurally similar to LSD, while <em>I. violacea</em> seeds lack these alkaloids entirely. This distinction is critical, as current legislative documents frequently misclassify non-psychoactive <em>I. violacea</em> as a controlled substance, inadvertently omitting the psychoactive <em>I. tricolor</em>. The analytical method is robust and precise, providing an effective forensic tool for the accurate identification of these botanically similar but chemically distinct species. Correct taxonomic and biochemical identification of these plants is essential to law enforcement and policy-makers for accurate legal scheduling and preventing regulatory misinterpretation regarding plant-derived psychoactive substances.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100686"},"PeriodicalIF":2.6,"publicationDate":"2025-07-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144665694","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}

引用次数: 0

Machine learning-enhanced traceability and particle analysis of pyrotechnic post-explosion residues using SEM/EDS 机器学习增强了烟火爆炸后残留物的可追溯性和颗粒分析

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-07-17 DOI: 10.1016/j.forc.2025.100685

Xing Li , Zhen-Wen Sun , Yan-Wu Yu , Gao-Qin Zhang , Guan-Nan Zhang , Yao Liu

{"title":"Machine learning-enhanced traceability and particle analysis of pyrotechnic post-explosion residues using SEM/EDS","authors":"Xing Li , Zhen-Wen Sun , Yan-Wu Yu , Gao-Qin Zhang , Guan-Nan Zhang , Yao Liu","doi":"10.1016/j.forc.2025.100685","DOIUrl":"10.1016/j.forc.2025.100685","url":null,"abstract":"<div><div>Mordern techniques such as spectroscopic and chromatographic techniques have advanced pyrotechnic precursor analysis, yet the forensic investigation methods of post-detonation residues remains limited, thereby constraining the identification of explosive sources. Pyrotechnic post-explosion residues (PPERs) retain stoichiometric signatures that can be linked to precursor formulations through machine learning-enhanced scanning electron microscopy / energy-dispersive X-ray spectroscopy (SEM/EDS) analysis, offering a foundation for further forensic study. This study presents a systematic approach to PPERs analysis with three key components: (1) the development of a test vessel and particles collection system for PPERs; (2) the employment of an automated SEM/EDS protocol incorporating the Particle X Perception System for high-throughput elemental and morphological characterization (15,000–38,000 particles per sample), and a data pretreatment analytical protocol that included morphometric screening criteria and multivariate statistical methods; (3) the construction of a machine learning framework integrating t-distributed Stochastic Neighbor Embedding (t-SNE) for dimensionality reduction and Random Forest Regression (RFR) for predictive modeling. The hybrid model demonstrated excellent clustering performance (Normalized Mutual Information (NMI) > 0.80) and high predictive accuracy (R<sup>2</sup> > 0.95, Root Mean Squared Error (RMSE) < 0.07), supporting the potential for pyrotechnical traceability from SEM/EDS data of PPERs.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100685"},"PeriodicalIF":2.6,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144685991","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}

引用次数: 0

Electron ionization fragmentation studies of ethoxy and methoxymethyl substituted phenylacetones 乙氧基和甲氧基甲基取代苯丙酮的电子电离破碎研究

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-07-09 DOI: 10.1016/j.forc.2025.100684

C. Randall Clark , Younis Abiedalla

{"title":"Electron ionization fragmentation studies of ethoxy and methoxymethyl substituted phenylacetones","authors":"C. Randall Clark , Younis Abiedalla","doi":"10.1016/j.forc.2025.100684","DOIUrl":"10.1016/j.forc.2025.100684","url":null,"abstract":"<div><div>The EI mass spectral fragmentation pathways and products were compared for substituted benzaldehydes and phenylacetones containing ethoxy and methoxymethyl substituents. The methoxymethylbenzene group is the only ether regioisomeric possibility with the ethoxybenzene group (and each have an isobaric relationship with the methylenedioxybenzene group) and are substituted in all three aromatic ring positions relative to the aldehyde and acetone moieties. The phenylacetones were synthesized from the corresponding precursor benzaldehydes. Stable isotope deuterium labeling in the ether substituents as well as product ion spectra and accurate mass time-of-flight analysis confirmed the structure of major fragments and allowed for prediction of the mechanisms of formation.</div><div>The methoxymethylbenzaldehydes yield a major fragment at <em>m/z</em> 135 via loss of the methyl radical. The ethoxy substituted isomers however have a base peak at <em>m/z</em> 121 via rearrangement loss of ethene followed by elimination of the aldehyde hydrogen radical. The EI mass spectra of ethoxyphenylacetones show the major ethoxybenzyl cation at <em>m/z</em> 135 via loss of the acetyl radical and the <em>m/z</em> 107 cation via elimination of ethene from the ethoxybenzyl cation. The EI mass spectra of methoxymethylphenylacetones are dominated by the radical cation at <em>m/z</em> 104 [C<sub>8</sub>H<sub>8</sub>]<sup>+•</sup>. Unique <em>meta</em>- specific radical cations at <em>m/z</em> 136 and <em>m/z</em> 108 were observed in 3-ethoxyphenylacetone. An <em>ortho</em> effect in methoxymethylphenylacetones yielded the unique fragments at <em>m/z</em> 121, <em>m/z</em> 146 and <em>m/z</em> 145. The results of this study identify <em>m/z</em> 107 and <em>m/z</em> 104 as unique marker ions for the differentiation of the regioisomeric ethoxy and methoxymethyl substituted phenylacetones.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100684"},"PeriodicalIF":2.6,"publicationDate":"2025-07-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144623866","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}

引用次数: 0

Characterization and classification of organic gunshot residue from neat smokeless powder, cartridge cases, and the hands of known shooters 从干净的无烟火药、弹壳和已知射手的手中提取的有机射击残留物的特征和分类

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-07-01 DOI: 10.1016/j.forc.2025.100683

Thomas D. Ledergerber , Liliana Barbosa , Kourtney Dalzell , Luis Arroyo , Tatiana Trejos

{"title":"Characterization and classification of organic gunshot residue from neat smokeless powder, cartridge cases, and the hands of known shooters","authors":"Thomas D. Ledergerber , Liliana Barbosa , Kourtney Dalzell , Luis Arroyo , Tatiana Trejos","doi":"10.1016/j.forc.2025.100683","DOIUrl":"10.1016/j.forc.2025.100683","url":null,"abstract":"<div><div>This study encompasses the detection, characterization, and classification of organic gunshot residue (OGSR) through the analysis of three forensically relevant sample types, including neat smokeless powders recovered from live ammunition, extracts from fired cartridge cases, and the hands of known shooters. Liquid chromatography-tandem mass spectrometry is used as an analytical tool for five manufacturer-grade ammunition brands. The relative detection and quantification of Akardite II, ethyl centralite, methyl centralite, diphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine is used for chemical characterization and to reveal main chemical changes during deflagration. Classification via discriminant analysis methods is effective for neat smokeless powders and spent cartridge cases, reaching correct classification rates as high as 83.7 %. Alternative chemometric techniques, including k-nearest neighbors and support vector machine algorithms, are more appropriate for residues recovered from the shooter's hands that exhibit greater inter-sample variability. The more challenging traces of hand residues yield correct classification rates of up to 62.7 %, partly due to significant changes in the formation of nitro-diphenylamines and Akardite II in some organic gunshot residue. The findings presented in this study demonstrate that analyzing OGSR can offer valuable insights into the discrimination of manufacturer-spent cartridges and, to some extent, hand residues, assisting in forensic investigations and shooting reconstructions when limited evidence is available.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100683"},"PeriodicalIF":2.6,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534856","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}

引用次数: 0

Development and comparison of reversed-phase ultra high-performance liquid chromatography (RP-UHPLC) and hydrophilic interaction liquid chromatography (HILIC) approaches to the analysis of regioisomeric fluorofentanyl derivatives and related compounds 反相高效液相色谱法（RP-UHPLC）与亲水性相互作用液相色谱法（HILIC）在氟芬太尼区域异构体衍生物及相关化合物分析中的应用及比较

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-06-29 DOI: 10.1016/j.forc.2025.100682

Jennifer K. Field , Benjamin S. Barrett , Erika Sitch , Ryan E. Mewis , William H. Campbell , Melvin R. Euerby , Oliver B. Sutcliffe

{"title":"Development and comparison of reversed-phase ultra high-performance liquid chromatography (RP-UHPLC) and hydrophilic interaction liquid chromatography (HILIC) approaches to the analysis of regioisomeric fluorofentanyl derivatives and related compounds","authors":"Jennifer K. Field , Benjamin S. Barrett , Erika Sitch , Ryan E. Mewis , William H. Campbell , Melvin R. Euerby , Oliver B. Sutcliffe","doi":"10.1016/j.forc.2025.100682","DOIUrl":"10.1016/j.forc.2025.100682","url":null,"abstract":"<div><div>This study describes the development and comparison of low, intermediate and high pH gradient RP-UHPLC-MS/MS with that of gradient HILIC-MS/MS analysis for a range of fluorofentanyl derivatives including four families of <em>ortho-</em>, <em>meta-</em> and <em>para</em>-regioisomers. High pH RP-UHPLC-MS/MS using an ammonium hydroxide and methanol gradient on a high pH stable SuperC18 column at low temperature was demonstrated to be the most successful chromatographic mode for separating 26 analytes including: regioisomeric fluorofentanyls (<em>n</em> = 10); fentanyl analogues (n = 10), despropionyl precursors (<em>n</em> = 4) and two commonly encountered related substances (heroin and xylazine). Low and intermediate pH RP-UHPLC failed to afford separation of many of the fluorofentanyl regioisomers on stationary phases possessing complementary selectivity with either acetonitrile or methanol over a wide temperature range. HILIC on a bare silica column using an acetonitrile and ammonium acetate / acetic acid gradient provided good separation of fluorofentanyl regiosiomers except for the despropionyl series. High pH gradient RP-UHPLC was demonstrated to provide orthogonal chromatographic selectivity to that of HILIC in the gradient analysis of 18 fentanyl and related substances. Seven isobaric fluorofentanyl structural isomers could be readily discriminated from the unique fragmentation ions obtained using positive electrospray ionization MS/MS. The optimum high pH RP-UHPLC chromatographic conditions for the separation of the fluorofentanyls was equally successful for the rapid separation of a wide range of fentanyl regio- and structural isomers.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100682"},"PeriodicalIF":2.6,"publicationDate":"2025-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144633796","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}

引用次数: 0

Exploiting a gold leaf-based voltammetric sensor for the estimation of firing distance 利用金箔伏安传感器估算射击距离

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-06-21 DOI: 10.1016/j.forc.2025.100681

Thinnapong Wongpakdee , Supatana Buking , Prapin Wilairat , Kanchana Uraisin , Nuanlaor Ratanawimarnwong , Duangjai Nacapricha

{"title":"Exploiting a gold leaf-based voltammetric sensor for the estimation of firing distance","authors":"Thinnapong Wongpakdee , Supatana Buking , Prapin Wilairat , Kanchana Uraisin , Nuanlaor Ratanawimarnwong , Duangjai Nacapricha","doi":"10.1016/j.forc.2025.100681","DOIUrl":"10.1016/j.forc.2025.100681","url":null,"abstract":"<div><div>In this study, we present a novel electrochemical approach for firing distance estimation using a gold leaf-based sensor integrated with screen-printed electrodes. This is the first report of employing a gold leaf-based sensor for the voltammetric estimation of firing distance by detecting Pb in gunshot residue (GSR) on fabric targets. The sensor consists of a gold leaf sheet as the working electrode, with carbon and silver/silver chloride screen-printed electrodes serving as the counter and reference electrodes, respectively. Pb(II), a key component of GSR, was extracted from 15 mm fabric discs using manual shaking in nitric acid for 3 min. The extracted solution was analyzed by anodic stripping voltammetry (ASV) with a portable electrochemical system. The Pb(II) signal was then correlated with the firing distance to construct an analytical curve for estimation of shooting distance in the range of 5–60 cm. The resulting mathematical model enables accurate distance estimation. This cost-effective, reagent-free, and field-deployable electrochemical sensor offers a rapid and accessible alternative for forensic firearm investigations.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100681"},"PeriodicalIF":2.6,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144490675","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}

引用次数: 0

Discovery of selective markers for chlorine gas exposure in concrete 发现混凝土中氯气暴露的选择性标记物

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-06-18 DOI: 10.1016/j.forc.2025.100680

Mirjam de Bruin-Hoegée , Bence Dallos , Tomas van Groningen , Jelle de Koning , Latifa Lamriti , Marcel J. van der Schans , Arian C. van Asten

{"title":"Discovery of selective markers for chlorine gas exposure in concrete","authors":"Mirjam de Bruin-Hoegée , Bence Dallos , Tomas van Groningen , Jelle de Koning , Latifa Lamriti , Marcel J. van der Schans , Arian C. van Asten","doi":"10.1016/j.forc.2025.100680","DOIUrl":"10.1016/j.forc.2025.100680","url":null,"abstract":"<div><div>Chlorine gas (Cl<sub>2</sub>) is still being used as a chemical weapon in modern war zones. After an attack with this toxic chemical, verifying its use is challenging due to its reactivity and rapid evaporation. Additionally, only a limited number of selective markers relating to the use of chlorine gas are found. For forensic purposes it is necessary to discriminate Cl<sub>2</sub> from other chlorine containing chemicals. Therefore, the current study aims to use gas chromatography–mass spectrometry (GC–MS) and liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS) together with machine learning methods to discover selective markers for chlorine gas exposure. Four types of concrete originating from Europe or the Middle East were exposed to various levels of Cl<sub>2</sub> as well as to some commonly used chlorine containing chemicals. After extraction with various solvents, the samples were analyzed. Based on the tentative identification of 32 chlorinated markers with GC–MS and 146 markers with LC-HRMS/MS, principal component analysis (PCA) and linear discriminant analysis (LDA) models were constructed. A clear distinction between concrete samples exposed to bleach and chlorine gas was apparent. For forensic classification, a Bayesian likelihood ratio (LR) model was applied that showed limited rates of misleading evidence and maximum LRs of 0.038 to 93. The markers chloroacetone, dichloroacetone, tetrachlorophenol, and 5-chloro-8-quinolinol were found to be selective for chlorine gas exposure. Their identity was verified by GC–MS/MS and LC-MS/MS in comparison with commercially available reference standards. In conclusion, this study demonstrates the feasibility of chemical profiling in concrete to differentiate among various chlorinating agents.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100680"},"PeriodicalIF":2.6,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144320787","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}

引用次数: 0

Improving inter-laboratory comparability of tooth enamel carbonate stable isotope analysis (δ13C, δ18O) 提高牙釉质碳酸盐稳定同位素分析（δ13C, δ18O）的实验室间可比性

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-06-14 DOI: 10.1016/j.forc.2025.100679

Chris Stantis , Lesley A. Chesson , Daniel L. Johnson , Thuan H. Chau , Kirsten A. Verostick , Gregory E. Berg , Gabriel J. Bowen

{"title":"Improving inter-laboratory comparability of tooth enamel carbonate stable isotope analysis (δ13C, δ18O)","authors":"Chris Stantis , Lesley A. Chesson , Daniel L. Johnson , Thuan H. Chau , Kirsten A. Verostick , Gregory E. Berg , Gabriel J. Bowen","doi":"10.1016/j.forc.2025.100679","DOIUrl":"10.1016/j.forc.2025.100679","url":null,"abstract":"<div><div>Carbon and oxygen isotope ratios of human tooth enamel carbonate are frequently used for reconstruction of past diet, movement, and environmental conditions. Despite a long legacy of research, samples are prepared and analyzed using a remarkably broad range of protocols, and this methodological heterogeneity raises questions about the comparability of isotopic data across studies. We report a systematic comparison of isotope delta (δ) values for 10 “modern” faunal teeth (obtained from field recoveries) measured in two different laboratories. Our tests included comparisons of enamel powder subsamples that were chemically pretreated using commonly adopted protocols and subsamples that received no pretreatment. We also evaluated δ values generated with and without (1) standardizing the reaction temperature used for sample acidification and (2) baking the samples and vials to remove moisture before analysis. The results showed that δ values from the two laboratories were systematically different when samples were chemically pretreated, but that differences were smaller or negligible for untreated samples. Standardization of acid reaction temperature and baking also improved comparability. We suggest that the widely adopted practice of chemical pretreatment of enamel samples is largely unnecessary and may compromise the accuracy of stable isotope analyses.</div><div><strong>Technology Readiness Level</strong>: TRL 4.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"45 ","pages":"Article 100679"},"PeriodicalIF":2.6,"publicationDate":"2025-06-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338893","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}

引用次数: 0