Forensic Chemistry最新文献

Electrodeposition of redox materials with potential for enhanced visualisation of latent finger-marks on brass substrates and ammunition casings. 电沉积氧化还原材料，具有增强黄铜基材和弹壳上潜在手印可视化的潜力。

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-04-19 DOI: 10.1016/j.forc.2025.100663

Colm McKeever, Eithne Dempsey

{"title":"Electrodeposition of redox materials with potential for enhanced visualisation of latent finger-marks on brass substrates and ammunition casings.","authors":"Colm McKeever, Eithne Dempsey","doi":"10.1016/j.forc.2025.100663","DOIUrl":"10.1016/j.forc.2025.100663","url":null,"abstract":"<div><div>Electrochemical methods can play a key role in the analysis of impression evidence, specifically, latent finger-marks on brass substrates and ammunition casings, the latter being commonly encountered at crime scenes in forensic casework. In adopting such techniques, forensic investigators can potentially overcome some of the challenges associated with traditional visualisation methods, the use of aggressive reagents, preservation of evidence integrity and the need for extensive sample preparation. The spatially selective deposition of conducting/redox active polymers for visualising latent finger-marks on typically low-yield brass ammunition casings is examined here, exploiting the electrodeposition of 3,4-ethylenedioxythiophene (EDOT), together with a first-time study of phenozine vs. phenothiazine monomers, and their combinations at sheet and cartridge brass. Fine tuning of electrochemical protocols and conditions together with optimised monomer feedstocks played a key role in the finger-mark visualisation quality achieved with insights into brass electrochemistry. EDOT-thionine emerged consistently as the most effective combination upon electrochemical deposition on brass sheets, revealing latent finger-marks (groomed) at the highest level of detail (level 3), including pores within the papillary ridges, using a low energy, rapid (<em>t</em> = 120 s) constant potential (<em>E</em><sub>app</sub> = 0.1 <em>V</em> vs Ag|AgCl) approach. Successful visualisation of groomed and natural (donor) latent finger-marks was achieved following exposure of brass to temperatures of 700 °C and > 15-month room temperature aging. Bespoke electrochemical cells designed to facilitate the use of ammunition casings as working electrodes produced excellent results via potential sweeping, resulting in pristine visualised latent finger-marks (groomed) of grade 3 quality with visible level 3 (> 50 %) features.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100663"},"PeriodicalIF":2.6,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855154","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

Application of the expert algorithm for substance identification (EASI) to the electron ionization (EI) mass spectra of fentanyl isomers and analogs 物质鉴定专家算法（EASI）在芬太尼异构体和类似物电子电离质谱中的应用

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-04-09 DOI: 10.1016/j.forc.2025.100660

Alexandra I. Adeoye , Glen P. Jackson

{"title":"Application of the expert algorithm for substance identification (EASI) to the electron ionization (EI) mass spectra of fentanyl isomers and analogs","authors":"Alexandra I. Adeoye , Glen P. Jackson","doi":"10.1016/j.forc.2025.100660","DOIUrl":"10.1016/j.forc.2025.100660","url":null,"abstract":"<div><div>Fentanyl analogs (fentalogs) share many structural and mass spectral similarities that make them difficult to differentiate and accurately identify without chromatographic data. In such situations, the expert algorithm for substance identification (EASI) provides superior classification relative to conventional approaches. Using a database of >57,000 replicate electron-ionization mass spectra of 76 fentalogs from ten laboratories, three challenging sets of isomers were studied in detail. To maximize limits of detection, only the 20 most abundant ions were considered. In each case, 50 % of the data from one laboratory served as the training set. On average, the mean absolute residuals between measured and modeled abundances of known positives were five times smaller using EASI than the consensus approach, which used the means of training sets as the exemplar spectra to which all query spectra were compared. With a conservative threshold of zero false positives, EASI identified isovalerylfentanyl from its two closest isomers with an accuracy of 96.7 %, which was ∼10 % better than the consensus approach. The associated positive likelihood ratios increased from 366 for the consensus approach to more than 4,200 for EASI. When discriminating isovalerylfentanyl spectra from the other 72 fentalogs, EASI provided errorless results with a positive likelihood ratio exceeding 50,000. For all 9 fentalogs, EASI outperformed the consensus approach and the use of Mahalanobis distance as a metric for identifying outliers. In the absence of retention time information, EASI improves confidence in drug identifications, enables inter-laboratory identifications, and reduces the need for acquiring concomitant spectra of standards.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100660"},"PeriodicalIF":2.6,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815981","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

Isotope fractionation during synthesis of methamphetamine from propiophenone, NaNO2 and dimethyl carbonate 丙烯酮、NaNO2和碳酸二甲酯合成甲基苯丙胺的同位素分馏

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-04-09 DOI: 10.1016/j.forc.2025.100661

Brendan M. Miller , James F. Carter , Sarah L. Cresswell , Wendy A. Loughlin , Peter N. Culshaw

{"title":"Isotope fractionation during synthesis of methamphetamine from propiophenone, NaNO2 and dimethyl carbonate","authors":"Brendan M. Miller , James F. Carter , Sarah L. Cresswell , Wendy A. Loughlin , Peter N. Culshaw","doi":"10.1016/j.forc.2025.100661","DOIUrl":"10.1016/j.forc.2025.100661","url":null,"abstract":"<div><div>Ephedrine remains a key precursor in the production of methamphetamine. A novel ephedrine-based route to methamphetamine involved the nitrosation of propiophenone to α-isonitrosopropiophenone, followed by catalytic hydrogenation to phenylpropanolamine (± − norephedrine). Cyclization-methylation of phenylpropanolamine to 3,4-dimethyl-5-phenyl-2-oxazolidinone using dimethyl carbonate, followed by basic hydrolysis or catalytic hydrogenolysis formed ephedrine or methamphetamine, respectively.</div><div>An investigation into the stable isotope fractionation during the synthesis of methamphetamine from propiophenone, NaNO<sub>2</sub> and dimethyl carbonate was performed using isotope ratio mass spectrometry. A negative isotopic shift was observed for <em>δ</em><sup>15</sup>N upon nitrosation of propiophenone to α-isonitrosopropiophenone, and a negative isotopic shift for <em>δ</em><sup>2</sup>H during catalytic hydrogenation of α-isonitrosopropiophenone to phenylpropanolamine. Minimal change in <em>δ</em><sup>13</sup>C was observed throughout the reaction until the methylation step with dimethyl carbonate, where a negative isotopic shift was observed.</div><div>The <em>δ</em><sup>13</sup>C values for the methamphetamine presented in a similar range to methamphetamine reported in previous work where the norephedrine/norpseudoephedrine was prepared <em>via</em> different starting materials (benzaldehyde and nitroethane), confirming that similar <em>δ</em><sup>13</sup>C values will result from fractionation during methylation with dimethyl carbonate regardless of the origin of the norephedrine/norpseudoephedrine. Chiral analysis confirmed methamphetamine to be racemic.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100661"},"PeriodicalIF":2.6,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815982","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

Rescuing fluorescence with steric hindrance: Perylene diimide based powder for latent fingerprint imaging 具有空间位阻的挽救荧光：苝二亚胺基粉末用于潜在指纹成像

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-04-08 DOI: 10.1016/j.forc.2025.100662

Rajdeep Kaur, Navjot Kaur, Prabhpreet Singh

引用次数: 0

A UHPLC-(ESI)MS/MS method for the determination of the psychedelic secondary metabolite mescaline in San Pedro (Trichocereus spp.) and its applicability for screening mescaline in other cacti varieties. 建立了一种hplc -(ESI)MS/MS法测定圣佩德罗（Trichocereus spp.）致幻次级代谢物美斯卡灵的含量及其在其他仙人掌品种中筛选美斯卡灵的适用性。

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-24 DOI: 10.1016/j.forc.2025.100659

Pragna Gaur , Liam Engel , Damian Robert Hall , Cheang Khoo , Jerome Sarris , Daniel Perkins , Chun Guang Li , Mitchell Low

{"title":"A UHPLC-(ESI)MS/MS method for the determination of the psychedelic secondary metabolite mescaline in San Pedro (Trichocereus spp.) and its applicability for screening mescaline in other cacti varieties.","authors":"Pragna Gaur , Liam Engel , Damian Robert Hall , Cheang Khoo , Jerome Sarris , Daniel Perkins , Chun Guang Li , Mitchell Low","doi":"10.1016/j.forc.2025.100659","DOIUrl":"10.1016/j.forc.2025.100659","url":null,"abstract":"<div><div>Commencements of clinical trials of psychedelic therapies for intractable forms of mental illnesses have drawn increased public attention to plants containing psychedelic substances. Whilst the psychoactive alkaloid mescaline has limited clinical trials, the San Pedro (<em>Trichocereus</em> spp.) cacti from which it is found have a long history of Indigenous medical and spiritual use. Traditional use remains licit in some jurisdictions, as supervised psychedelic dosage is typically regarded as tolerable with reports of only mild intoxications and few persisting negative psychological effects. However, mescaline concentration in ornamental San Pedro is highly variable, introducing risk of unintentional low or high dosage if misdirected for illicit use. This paper reports a validated UHPLC-(ESI)MS/MS method for the convenient and rapid quantification of mescaline in San Pedro, and for screening twelve potentially untested cacti. Preliminary results indicated that there may be higher amounts of mescaline in the chlorenchyma than the parenchyma of San Pedro. While six cacti lacked detectable mescaline, our screening enabled the first quantifications of mescaline in two varieties of <em>Echinopsis subdenudata</em> from 36 μg g<sup>−1</sup> to 2.45 mg g<sup>−1</sup>. Chemotaxonomically, this amount of mescaline in a species from the traditional <em>Echinopsis</em> genus further suggests that the <em>Trichocereus</em> genus is not distinct and may support their contested combination into a single genus. Forensically, the identification of a popular ornamental cactus that was previously not known to contain mescaline demonstrates the need for routine screening of other cacti for the forensic sciences to remain ahead of emerging trends in psychedelic drug use.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100659"},"PeriodicalIF":2.6,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143760935","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}

引用次数: 0

Incorporating organic gunshot residue into the forensic workflow: A study of preservation and stability of the pGSR and OGSR 将有机射击残留物纳入法医工作流程：pGSR和OGSR的保存和稳定性研究

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-22 DOI: 10.1016/j.forc.2025.100651

Kourtney A. Dalzell , Thomas Ledergerber , Tatiana Trejos , Luis E. Arroyo

{"title":"Incorporating organic gunshot residue into the forensic workflow: A study of preservation and stability of the pGSR and OGSR","authors":"Kourtney A. Dalzell , Thomas Ledergerber , Tatiana Trejos , Luis E. Arroyo","doi":"10.1016/j.forc.2025.100651","DOIUrl":"10.1016/j.forc.2025.100651","url":null,"abstract":"<div><div>In recent years, trace evidence examiners started to assess the value of incorporating two complementing analytical measurements: primer residue (pGSR) and organic gunshot residue (OGSR) data, aiming to strengthen firearms-related investigations. Still, there is a need to understand the cost-benefit of any method's modification for collecting, analyzing, and interpreting the combined information. This study aims to answer practical questions concerning optimal storage conditions for OGSR and pGSR, the feasibility of sequential analysis on the same sample, and whether pGSR or OGSR should be analyzed first. Samples were collected from shooters (<em>n</em> = 128) using a standard carbon adhesive stub. The stability of OGSR and pGSR was evaluated at the time elapsed from collection at the scene until analysis at the laboratory (1, 2 days, 1, 2 weeks, and 1, 2, 6 months) and storage conditions (room temperature or freezer). The experimental design includes the effect of the analysis sequence by either liquid chromatography-mass spectrometry (LC-MS/MS) and scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDS) on the detection rates. The results indicate a multi-testing approach does not compromise the integrity of pGSR or OGSR evidence when following appropriate protocols. The detection of OGSR and pGSR is not significantly different at the studied storage conditions or times when samples are preserved in sealed SEM stubs. These findings may alleviate some concerns regarding the feasibility of conducting an OGSR examination on samples that cannot be submitted to the laboratory immediately after collection and assist agencies in establishing preservation, storage, and acceptance criteria for future adoption.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100651"},"PeriodicalIF":2.6,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706322","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

Extraction approaches for A-230, A-234, VX, and sarin nerve agents from surface coatings 从表面涂层中提取A-230， A-234， VX和沙林神经毒剂的方法

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-22 DOI: 10.1016/j.forc.2025.100658

Tomáš Rozsypal

{"title":"Extraction approaches for A-230, A-234, VX, and sarin nerve agents from surface coatings","authors":"Tomáš Rozsypal","doi":"10.1016/j.forc.2025.100658","DOIUrl":"10.1016/j.forc.2025.100658","url":null,"abstract":"<div><div>Nerve agents are among the most hazardous chemical warfare agents (CWAs) due to their extreme toxicity. This study optimized methods for extracting CWAs (A-230, A-234, VX, and sarin) from surface coatings, a common but chemically complex matrix in urban environments. Four types of coatings (nitrocellulose, polyurethane, acrylic, and alkyd) were tested using bulk, wipe, and scrape extraction approaches with various solvents. Versatile methods were successfully developed for all four analytes across all four matrices, and recoveries were also determined for additional CWAs (soman, cyclosarin, and sulfur mustard). Bulk extraction consistently achieved the highest recoveries, while wipe extraction offered a practical alternative with slightly reduced efficiency. Scrape extraction exhibited high variability and was unsuitable for volatile compounds like sarin. The methods were evaluated using gas chromatography with flame ionization detection, demonstrating robust analytical performance, including high sensitivity, precision, minimized matrix effects, and validated accuracy through spiking recoveries. Persistence studies revealed slow dissipation rates in surface coatings, underscoring their forensic potential when other matrices yield only degradation products. A-230 and A-234 were detectable in all coatings for up to 56 days, whereas sarin dissipated rapidly, especially in acrylic paint. VX remained primarily in surface layers due to its high viscosity and limited diffusion. These findings highlight the importance of tailoring extraction methods to specific matrices and agents. Coatings, with their prolonged retention of CWAs, not only provide significant forensic value but also emphasize the need for targeted decontamination strategies to mitigate environmental and human health risks.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100658"},"PeriodicalIF":2.6,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143706321","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

Analysis of substituted Cathinones and fentanyl analogs by gas chromatography-infrared spectroscopy (GC-IRD) using nitrogen carrier gas 氮载气气相色谱-红外光谱法分析取代卡西酮和芬太尼类似物

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-18 DOI: 10.1016/j.forc.2025.100654

Marcus L. Warner

{"title":"Analysis of substituted Cathinones and fentanyl analogs by gas chromatography-infrared spectroscopy (GC-IRD) using nitrogen carrier gas","authors":"Marcus L. Warner","doi":"10.1016/j.forc.2025.100654","DOIUrl":"10.1016/j.forc.2025.100654","url":null,"abstract":"<div><div>Substituted cathinones and fentanyl analogs that are positional isomers can produce similar mass spectra and retention times, which poses challenges for their identification. A gas chromatography-infrared spectroscopy (GC-IRD) method, developed using nitrogen as the carrier gas, was employed as a complimentary technique to gas chromatography-mass spectroscopy (GC–MS) for the accurate identification of positional isomers. Due to the global helium shortage and since Agilent helium (nitrogen switch) conservation modules were currently in use, nitrogen was selected and a novel method was developed for the analysis of controlled substances. A total method run time of 26 min for the analysis of 29 certified reference materials comprised of substituted cathinones and fentanyl analogs was achieved. A drug mixture was also analyzed to evaluate the resolution and retention time. Standards were prepared at concentrations of 100 μg/mL, 1 mg/mL and 2 mg/mL and analyzed over a 3-day period, where the 2 mg/mL concentrations of the standards were run in triplicate on day 1 and once on days 2 and 3. Twenty-seven of the standards were identified with a library match of 0.98 or higher for the 1 mg/mL concentration. Each standard experienced a retention time (RT) coefficient of variation (%CV) less than 3 %. For the drug mixture peak resolution exceeded 1.5 for each component. The GC-IRD validated method was found to be a suitable complementary analysis technique to GC–MS for analyzing substituted cathinones and fentanyl analogs, as demonstrated by the repeatable and reproducible RTs and library matches obtained during method validation.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100654"},"PeriodicalIF":2.6,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143682670","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

Chemical attribution signatures of nordiazepam for the determination of synthetic routes 用于合成路线确定的去甲地西泮的化学属性特征

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-13 DOI: 10.1016/j.forc.2025.100653

Meng Jin , Zixuan Zhang , Xiaogang Lu , Qian Wang , Runli Gao , Fengxia Sun , Hongmei Wang

引用次数: 0

Evaluating machine learning methods on a large-scale of in silico fire debris data 在大规模的计算机火灾碎片数据上评估机器学习方法

IF 2.6 3区医学

Forensic Chemistry Pub Date : 2025-03-12 DOI: 10.1016/j.forc.2025.100652

Larry Tang , Slun Booppasiri , Michael E. Sigman , Mary R. Williams

{"title":"Evaluating machine learning methods on a large-scale of in silico fire debris data","authors":"Larry Tang , Slun Booppasiri , Michael E. Sigman , Mary R. Williams","doi":"10.1016/j.forc.2025.100652","DOIUrl":"10.1016/j.forc.2025.100652","url":null,"abstract":"<div><div>A large dataset of 240,000 fire debris samples have been generated in-silico using a data augmentation method at National Center for Forensic Science. The IS samples contain balanced data with 50 % samples having ignitable liquid residue and 50 % only having substrate components. In the big data era, this large dataset is useful for researchers to develop and implement their new machine learning methods. In this paper, we split the data into a training dataset and a test dataset. We then trained seven machine learning methods including logistic regression, least discriminant analysis, quadratic discriminant analysis, support vector machine, random forest, XGBoost, and neural network on an in-silico training dataset. The predictive accuracy and area under the ROC (AUC) of the models was evaluated and compared on both an in-silico test dataset and on an experimental fire debris dataset. In addition, we analyzed both TIS and TIC datasets. For the TIS dataset, neural network provides the highest AUC in both in-silico test and experimental fire debris dataset. Random forest shows the highest performance for the TIC dataset when we binned the retention index.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"44 ","pages":"Article 100652"},"PeriodicalIF":2.6,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143619350","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