Forensic Chemistry最新文献

Simultaneous analysis of opioid drugs used for pain in whole blood using liquid chromatography/time-of-flight mass spectrometry coupled with dried blood spots and solid-phase dispersive extraction 用液相色谱/飞行时间质谱联用干血斑和固相分散萃取法同时分析全血中用于止痛的阿片类药物

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-12-09 DOI: 10.1016/j.forc.2025.100717

Koichi Saito, Rika Nishiyama, Rie Ito

This study targeted 11 opioid analgesics with a high potential for dependence and abuse—morphine, fentanyl, oxycodone, methadone, pethidine, codeine, tramadol, pentazocine, buprenorphine, naloxone, and O-desmethyltramadol—to develop a rapid, simple, and sensitive screening method for whole blood analysis. A pretreatment procedure was established that combines dried blood spot (DBS) extraction with solid-phase dispersive extraction (SPDE) cleanup using Captiva ND ^Lipids to remove phospholipids effectively. Analysis was performed by liquid chromatography coupled with time-of-flight mass spectrometry (LC/TOF-MS). The combined DBS–SPDE approach improved the precision of the recovery tests, and peaks likely originating from phospholipids observed with DBS extraction alone disappeared, indicating efficient phospholipid removal. The limits of detection and quantification for the 11 opioids were 0.02–0.05 ng/mL and 0.05–0.1 ng/mL, respectively. Validation results showed good trueness for most opioids (83.6–115.7 %), although morphine, buprenorphine, and naloxone exhibited lower values (24.2–49.0 %). Precision was satisfactory, with repeatability below 15 % and intermediate precision below 20 % for most analytes, except for morphine and buprenorphine, which showed slightly higher variability. These findings demonstrate that the proposed LC/TOF-MS method achieves sufficient sensitivity and reproducibility for screening purposes. The method offers a practical tool for identifying opioids and monitoring therapeutic drug levels in forensic and clinical applications.

本研究针对吗啡、芬太尼、羟考酮、美沙酮、哌替啶、可待因、曲马多、戊唑嗪、丁丙诺啡、纳洛酮、o -去甲基曲马多等11种依赖性和滥用可能性高的阿片类镇痛药，建立一种快速、简便、灵敏的全血筛查方法。建立了一种将干血斑（DBS）萃取与固相分散萃取（SPDE）清洗相结合的预处理工艺，使用Captiva ND Lipids有效地去除磷脂。采用液相色谱-飞行时间质谱法（LC/TOF-MS）进行分析。DBS - spde联合方法提高了回收率测试的精度，DBS单独提取观察到的磷脂可能产生的峰消失，表明有效的磷脂去除。11种阿片类药物的检出限和定量限分别为0.02 ~ 0.05 ng/mL和0.05 ~ 0.1 ng/mL。验证结果显示，大多数阿片类药物的正确率为83.6 ~ 115.7%，吗啡、丁丙诺啡和纳洛酮的正确率较低（24.2 ~ 49.0%）。精密度令人满意，大多数分析物的重复性低于15%，中间精密度低于20%，但吗啡和丁丙诺啡的变异性略高。这些结果表明，LC/TOF-MS方法具有足够的灵敏度和可重复性。该方法为鉴定阿片类药物和监测法医和临床应用中的治疗药物水平提供了实用工具。

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引用次数: 0

From on-site color change to forensic evidence: Smartphone-operated tristimulus evaluation of detection tubes for chemical warfare agent vapors 从现场颜色变化到法医证据：智能手机操作的化学战剂蒸汽检测管的三刺激评估

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-11-27 DOI: 10.1016/j.forc.2025.100714

Tomas Rozsypal , Victor Bocos-Bintintan

Rapid, objective, and defensible detection of chemical warfare agents .CWAs) at incident scenes remains a critical challenge in forensic chemistry. Detector tubes, widely used by military and emergency services, are low-cost and simple but traditionally provide only subjective yes/no results. Here, we demonstrate the first field-deployable approach that upgrades these tubes into semi-quantitative forensic tools by coupling them with an inexpensive portable tristimulus colorimeter that can be operated either directly on-device or via a free Android application.

Using tubes for sarin (GB), hydrogen cyanide (AC), and sulfur mustard (HD), color responses were evaluated in CIE-L*a*b* space. Analytical parameters—including repeatability at fixed spots, intra−/interday precision, calibration models, stabilization times, and colorimetric detection thresholds (CDTs)—were systematically characterized. Instrumental colorimetry reduced CDTs by approximately one order of magnitude (5–20×) compared to conventional naked-eye inspection, providing faster, more reproducible, and quantifiable results. Calibration was linear for AC and HD and followed a power-law model for GB, with uncertainties ≤15 % except for heterogeneous AC layers (≤40 %).

This workflow converts subjective visual inspection into objective, archivable digital records suitable for forensic documentation. Compared to advanced field instruments such as ion mobility spectrometers, it delivers actionable semi-quantitative data at a fraction of the cost and logistical burden. While the method is inherently limited by the heterogeneity of indicator layers and possible matrix effects, these factors do not outweigh its forensic advantages, particularly its enhanced sensitivity, reproducibility, and trace-level applicability for both military and civilian chemical incident response.

快速、客观、可防御的化学战剂探测。在事故现场的CWAs仍然是法医化学的一个关键挑战。探测管广泛用于军事和应急服务，成本低且简单，但传统上只能提供主观的是/否结果。在这里，我们展示了第一种可现场部署的方法，将这些管升级为半定量法医工具，通过将它们与廉价的便携式三刺激色度计相结合，可以直接在设备上操作，也可以通过免费的Android应用程序操作。使用沙林（GB）、氰化氢（AC）和芥子气（HD）的色谱管，在CIE-L*a*b*空间中评价颜色反应。分析参数-包括定点重复性，日内/日间精度，校准模型，稳定时间和比色检测阈值(CDTs) -系统表征。与传统的裸眼检测相比，仪器比色法将CDTs降低了大约一个数量级（5 - 20倍），提供了更快、更可重复性和可量化的结果。AC和HD的校准是线性的，GB的校准遵循幂律模型，除异质AC层（≤40%）外，不确定性≤15%。该工作流程将主观的视觉检查转换为客观的、可归档的数字记录，适用于法医文件。与先进的现场仪器（如离子迁移谱仪）相比，它可以以很小的成本和后勤负担提供可操作的半定量数据。虽然该方法受到指示层的异质性和可能的矩阵效应的固有限制，但这些因素并没有超过其法医优势，特别是其增强的灵敏度、可重复性和对军用和民用化学事件响应的痕量水平适用性。

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引用次数: 0

Performance of fentanyl test wipes based on eosin Y dye 基于伊红Y染料的芬太尼试验湿巾性能研究

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-11-13 DOI: 10.1016/j.forc.2025.100713

Christian Gabriel El Azar, Anita Amate, Marya Lieberman

Fentanyl test wipes (FTW) based on the color reaction between fentanyl and the dye Eosin Y have been advertised for use in detecting fentanyl in neat powders, pills, liquids and for detection of fentanyl on contaminated surfaces such as tabletops. This study explores the functionality and accuracy associated with FTW. The sensitivity of the wipes was tested with fentanyl and fentanyl analogs in concentrated solutions, solids with relatively high weight percentages of fentanyl and with fentanyl in dilute solutions or solids with relatively low w/w percentages of fentanyl. Specificity was evaluated by applying the wipes to a wide range of pharmaceuticals and common household products. The FTW gave the expected orange-to-pink color change only in the presence of relatively concentrated fentanyl and fentanyl analogs. Application of FTW to 94 pharmaceuticals and common household products revealed many false positives. As foreshadowed by literature uses of Eosin Y for the detection of various amines, false positive results were observed for 36% of substances containing amine groups. False positives were also observed for common household substances that do not contain amine functional groups, such as talc and Vitamin C. The high rate of false positives with common substances and the low sensitivity for fentanyl of these Eosin Y-based test wipes should be taken into account when selecting presumptive tests for forensic and public health applications.

基于芬太尼与染料伊红Y之间颜色反应的芬太尼测试湿巾（FTW）已被宣传用于检测纯粉末、药丸、液体中的芬太尼，以及检测受污染表面（如桌面）上的芬太尼。本研究探讨了与FTW相关的功能和准确性。用芬太尼和芬太尼类似物的浓溶液、芬太尼质量百分比相对较高的固体、芬太尼的稀溶液或芬太尼w/w百分比相对较低的固体对湿巾进行敏感性测试。通过将湿巾应用于广泛的药品和普通家用产品来评估特异性。只有在相对浓度的芬太尼和芬太尼类似物存在的情况下，FTW才会出现预期的橙色到粉红色的变化。将FTW应用于94种药品和普通家用产品，发现许多假阳性。正如文献中使用伊红Y检测各种胺所预示的那样，对含有胺基的物质观察到36%的假阳性结果。对于不含胺官能团的普通家用物质，如滑石粉和维生素c，也观察到假阳性。在为法医和公共卫生应用选择推定测试时，应考虑到普通物质的高假阳性率和这些基于伊红的测试湿巾对芬太尼的低敏感性。

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引用次数: 0

Assessing the expanded capacity of modern μ-XRF SDD systems for forensic analysis through an interlaboratory study: Part II—Vehicle glass 通过实验室间研究评估用于法医分析的现代μ-XRF SDD系统的扩展能力：第二部分-车辆玻璃

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-11-13 DOI: 10.1016/j.forc.2025.100712

Zachary Andrews , Cedric Neumann , Troy Ernst , John Chester , Kris Gates , Christine Gregory , Susan Gross , Anne Kisler-Rao , James Marano , Tatiana Trejos

Forensic laboratories have widely adopted micro-X-ray fluorescence (μXRF) spectrometry for glass examinations and benefit from its scientific validity and standard test methods. Recently, modern silicon drift detectors (SDD) started replacing traditional silicon-doped lithium (SiLi) detectors. This interlaboratory study addresses the need to adapt protocols designed for SiLi detectors to modern systems. Eight participants received two standard reference glasses and 100 fragments from ten sets of windshield glass. Although performance varied by instrument configuration, generally, the μXRF-SDD offered improved sensitivity (2–10 times), faster acquisition (1200 Ls to 300 Ls), and allowed lower sample sizes (spot sizes from 100–300 μm to 20–30 μm) compared to older SiLi systems. Each participant conducted 45 known-to-questioned pairwise comparisons without knowing the ground truth of the samples' origin. Of these, 28 were from the same source, and 17 from different sources. Overall, 800 spectral files were compared using spectral overlay and comparison intervals of elemental ratios (3 s and modified 3 s). Spectral overlay provided correct inclusions and exclusions for all comparisons across participants. The comparison intervals did not produce false inclusions. The modified 3 s interval accounted for the improved precision, reducing false exclusions from 16.3 % to 4.7 % compared to the 3 s criteria. Increasing the number of fragments of the known sample may compensate for heterogeneities derived from analyzing smaller areas. Additionally, spectral contrast angle ratios (SCAR) and Score Likelihood Ratios (SLR) assisted with data interpretation and comparisons across laboratories, offering a complementary tool to enhance objectivity in spectral comparisons.

显微x射线荧光（μXRF）光谱法已广泛应用于玻璃检测，并受益于其科学有效性和标准的测试方法。近年来，现代硅漂移探测器（SDD）开始取代传统的掺硅锂探测器（SiLi）。这个实验室间的研究解决了需要适应为硅离子探测器设计的协议，以适应现代系统。8名参与者获得了两副标准参考眼镜和10套挡风玻璃的100块碎片。虽然性能因仪器配置而异，但总体而言，与旧的SiLi系统相比，μXRF-SDD提供了更高的灵敏度（2-10倍），更快的采集速度（1200 l到300 l），并且允许更小的样品尺寸（光斑尺寸从100-300 μm到20-30 μm）。每个参与者在不知道样本来源的基本真相的情况下进行了45次已知问题的两两比较。其中28份来自同一来源，17份来自不同来源。利用光谱叠加和元素比比较间隔（3 s和修改后的3 s）对800个光谱文件进行了比较。光谱覆盖为所有参与者之间的比较提供了正确的包含和排除。比较间隔没有产生假包含。修改后的3秒间隔提高了精度，与3秒标准相比，将误排除率从16.3%降低到4.7%。增加已知样品的碎片数量可以弥补分析较小区域产生的不均匀性。此外，光谱对比角比（SCAR）和评分似然比（SLR）有助于实验室间的数据解释和比较，为提高光谱比较的客观性提供了补充工具。

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引用次数: 0

Estimating post-mortem interval (PMI) through purine analysis in muscle tissue using extreme gradient boosting 通过使用极端梯度增强对肌肉组织进行嘌呤分析来估计死后时间间隔

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-11-10 DOI: 10.1016/j.forc.2025.100711

Claudio Tersaruolo , Orla Howe , Jesus Frias

Post-mortem biochemical changes in muscle tissue can serve as valuable indicators for estimating the post-mortem interval (PMI), following time and temperature-dependent patterns. This study focused on purine compounds: adenosine, inosine, hypoxanthine, and xanthine as potential biochemical markers of PMI.

Muscle tissue samples were collected from Sus scrofa domesticus (domestic pigs) and were stored at 10 °C, 20 °C, and 30 °C and then analysed over 8 consecutive days. Concentrations of four purines were measured throughout this period to examine their post-mortem kinetics. Using these data, we developed predictive machine learning model to assess PMI based on Extreme Gradient Boosting (XGBoost), a machine learning algorithm capable of modelling complex temporal trends.

Among the compounds, inosine, hypoxanthine, and xanthine showed clear and consistent degradation patterns, while adenosine remained relatively stable. Our results show that by using multiple consecutive post-mortem measurements, it significantly improved the model's predictive accuracy, highlighting the value of short-term repeated sampling.

These findings support the potential of combining purine analysis with machine learning to estimate PMI and demonstrate that short sequential sampling of those compounds can be useful for forensic applications even though validation under more variable post-mortem conditions is still needed.

死后肌肉组织的生化变化可以作为估计死后间隔（PMI）的有价值的指标，遵循时间和温度依赖模式。本研究的重点是嘌呤化合物：腺苷、肌苷、次黄嘌呤和黄嘌呤作为PMI的潜在生化标志物。从家猪（Sus scrofa domesticus，家猪）身上采集肌肉组织样本，分别于10°C、20°C和30°C保存，然后连续8天进行分析。在此期间测量了四种嘌呤的浓度，以检查它们的死后动力学。利用这些数据，我们开发了基于极端梯度增强（XGBoost）的预测机器学习模型来评估PMI， XGBoost是一种能够模拟复杂时间趋势的机器学习算法。其中，肌苷、次黄嘌呤和黄嘌呤的降解模式清晰一致，而腺苷则保持相对稳定。我们的研究结果表明，通过使用多个连续的死后测量，它显著提高了模型的预测精度，突出了短期重复采样的价值。这些发现支持了将嘌呤分析与机器学习相结合来估计PMI的潜力，并证明了这些化合物的短序列采样对于法医应用是有用的，尽管仍然需要在更可变的死后条件下进行验证。

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引用次数: 0

Differentiation of methyl-substituted fentanyl analogs using optimized weighting within the inverted library search algorithm (ILSA) 利用反向文库搜索算法（ILSA）优化加权区分甲基取代芬太尼类似物

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-11-09 DOI: 10.1016/j.forc.2025.100710

Christany Liggins , Alleigh N. Couch , Arun S. Moorthy , J. Tyler Davidson

The ongoing opioid epidemic in the United States is predominantly driven by fentanyl and its analogs. The structural similarity of these analogs makes them difficult to differentiate using traditional seized drugs screening techniques, such as colorimetric testing or gas chromatography-electron ionization-mass spectrometry (GC-EI-MS). Direct analysis in real time-mass spectrometry (DART-MS) is an alternative rapid screening technique; however, the resulting mass spectra can be challenging to interpret. The National Institute of Standards and Technology (NIST) developed the Data Interpretation Tool (DIT) to address this challenge. The DIT utilizes the inverted library search algorithm (ILSA) to assist analysts with mixture interpretation. Unfortunately, both similarity scoring metrics, the reverse match factor (RevMF) and fraction of peak intensity explained (FPIE), struggle with isomer differentiation.

This research evaluates optimized weighting of the scoring metrics used by the ILSA to improve the differentiation of isobaric methyl-substituted fentanyl analogs. Characterization of eight methyl-substituted fentanyl analogs led to the differentiation of analogs with different R-group substitution locations. This research demonstrates improved differentiation of isobaric fentanyl analogs when utilizing the RevMF score. In comparison to the FPIE score, the RevMF score demonstrated improved performance with equal weighting of the higher fragmentation spectra (i.e., RevMF 50:50) and target identification with the low fragmentation spectrum. A 0.80 RevMF 50:50 threshold was established that yielded reduced false positives. Overall, this study highlights potential improvements for the ILSA through optimized weighting, providing enhanced isomer differentiation, as demonstrated for methyl-substituted fentanyl analogs.

美国持续的阿片类药物流行主要是由芬太尼及其类似物驱动的。这些类似物的结构相似性使得它们难以使用传统的缉获药物筛选技术进行区分，例如比色测试或气相色谱-电子电离-质谱（GC-EI-MS）。直接实时质谱分析（DART-MS）是一种替代的快速筛选技术；然而，由此产生的质谱可能很难解释。美国国家标准与技术研究所（NIST）开发了数据解释工具（DIT）来应对这一挑战。DIT利用倒文库搜索算法（ILSA）来辅助分析人员进行混合解释。不幸的是，两个相似度评分指标，反向匹配因子（RevMF）和峰强度解释分数（FPIE），都难以区分异构体。本研究评估了ILSA用于改善等压甲基取代芬太尼类似物分化的评分指标的优化加权。表征八种甲基取代芬太尼类似物导致类似物具有不同的r -基团取代位置的分化。本研究表明，当使用RevMF评分时，可改善等压芬太尼类似物的分化。与FPIE分数相比，RevMF分数在高碎片谱（即RevMF 50:50）和低碎片谱的目标识别权重相等的情况下表现出更好的性能。建立了一个0.80 RevMF 50:50的阈值，产生了减少的假阳性。总的来说，本研究强调了通过优化加权对ILSA的潜在改进，提供了增强的异构体分化，如甲基取代芬太尼类似物。

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引用次数: 0

Detection of TATP in vapour phase: Influence of the packaging 气相中TATP的检测：包装的影响

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-10-28 DOI: 10.1016/j.forc.2025.100708

L. Jeunieau, L. Brion, S. Chantrain, B. Simoens

The threat posed by improvised explosive devices (IEDs) remains significant, making early detection a security priority. Among available detection techniques, explosive detection dogs (EDD) are still considered one of the most effective tools for detecting explosives in the vapour phase. However, packaging materials can significantly influence the availability of explosive vapours thereby affecting their detection. This study investigates the diffusion behaviour of triacetone triperoxide (TATP), a common homemade explosive, through various packaging materials.

TATP diffusion was analysed using Solid Phase Microextraction (SPME) and Getxent tubes. Experiments were conducted using up to four successive polyethylene (PE) bags. The results demonstrated that most of the TATP vapour diffuses through the bag's seal rather than through the polymer matrix itself. Furthermore, the quantity of TATP inside the packaging did not influence the diffusion rate, as the vapour concentration is governed by TATP's vapour pressure, which is independent of the sample mass.

Diffusion through a plastic bottle was also evaluated and found to be slower than through PE bags. In contrast, no diffusion of TATP was detected through sealed aluminium-coated polymer bags, indicating a complete barrier effect.

Detection tests with trained EDDs corroborated with the analytical results: dogs consistently detected TATP stored in PE bags and plastic bottles but failed to do so when the explosive was sealed in aluminium-coated bags. These findings confirm that packaging plays a crucial role in the detectability of explosives by EDD.

简易爆炸装置（ied）构成的威胁仍然很大，因此早期发现是安全工作的重点。在现有的探测技术中，爆炸物探测犬仍然被认为是探测气相爆炸物最有效的工具之一。然而，包装材料可以显著影响爆炸性蒸汽的可用性，从而影响其检测。本文研究了一种常见的自制炸药三过氧化三丙酮（TATP）在不同包装材料中的扩散行为。采用固相微萃取（SPME）和Getxent管对TATP扩散进行了分析。实验使用多达四个连续的聚乙烯（PE）袋进行。结果表明，大部分TATP蒸汽通过袋的密封扩散，而不是通过聚合物基体本身。此外，包装内TATP的数量并不影响扩散速率，因为蒸气浓度由TATP的蒸气压决定，而蒸气压与样品质量无关。通过塑料瓶的扩散也进行了评估，发现比通过PE袋的扩散要慢。而密封的包铝聚合物袋则没有检测到TATP的扩散，表明有完全的阻隔作用。用训练有素的EDDs进行的检测试验证实了分析结果：警犬始终能检测到储存在PE袋和塑料瓶中的ttp，但当炸药被密封在镀铝袋中时却无法检测到。这些发现证实了包装在EDD检测爆炸物的可探测性中起着至关重要的作用。

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引用次数: 0

Multimodal analytical approach applied to whisky labels for authenticity determination 多模态分析方法在威士忌标签真实性测定中的应用

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-10-28 DOI: 10.1016/j.forc.2025.100709

Veronika Tibljas , Simona Francese , Jef Clark , Ian Goodall , Frazer Birch , Robert Bradshaw

Alcohol counterfeiting presents a significant global challenge, posing serious health risks and economic losses. Whisky, a leading UK commodity export, is a common target for counterfeiting due to its high value and global demand. Counterfeit detection of this and similar products most often involves analysis of the liquid content, which requires opening of the products. This study explores a multimodal analytical workflow for whisky label authentication, integrating Raman spectroscopy, desorption electrospray ionisation mass spectrometry imaging (DESI MSI), and matrix-assisted laser desorption/ionisation mass spectrometry imaging (MALDI MSI). Raman spectroscopy provides a rapid, non-invasive method that can be used as initial testing. The subsequent application of DESI MSI and MALDI MSI in sequence maximises the chemical intelligence obtained from the labels and strengthens confidence in counterfeit identification, with additional potential presented for quality control (QC) in label printing and design.

假酒是一项重大的全球挑战，造成严重的健康风险和经济损失。威士忌是英国主要的出口商品，由于其高价值和全球需求，是假冒的共同目标。这种产品和类似产品的假冒检测通常涉及分析液体含量，这需要打开产品。本研究探索了威士忌标签认证的多模态分析工作流程，整合了拉曼光谱、解吸电喷雾质谱成像（DESI MSI）和基质辅助激光解吸/电离质谱成像（MALDI MSI）。拉曼光谱提供了一种快速，非侵入性的方法，可用于初始测试。随后依次应用DESI MSI和MALDI MSI，最大限度地提高了从标签中获得的化学情报，增强了对假冒识别的信心，并为标签印刷和设计中的质量控制（QC）提供了额外的潜力。

引用次数: 0

Evaluation of fingerprint aging using near infrared hyperspectral imaging with partial least squares-discriminant analysis 基于偏最小二乘判别分析的近红外高光谱指纹老化评价

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-10-27 DOI: 10.1016/j.forc.2025.100707

Caroline R. Carneiro , Carolina S. Silva , Jez W.B. Braga , Ingrid T. Weber

Fingerprints are forensic evidence commonly found at crime scenes. In addition to being widely used for human identification purposes, they can also be used for dating, contributing information to criminal investigations. Despite the enormous gain that can be obtained with this type of approach, there is no reliable analytical method to estimate the age of a fingerprint. Aging is a complex and uncontrolled process, and changes are affected by factors such as time and environmental conditions. This study sought to evaluate the possibility of dating fingerprints using near-infrared hyperspectral images (NIR-HSI) using the chemometric tool Discriminant Analysis by Partial Least Squares (PLS-DA). Fingerprints from 6 volunteers were analyzed over an 8-week aging period, with this period divided into distinct time intervals for further classification. This resulted in three PLS-DA models that were compared: the first one with 8 classes, the second one with 4 classes and the last with only 2 classes. In the first model, 5.56 % of the prediction samples were correctly classified, while in the second model, a success rate of 30.56 % was obtained and the third model achieved a 63.89 % success rate. This highlights the difficulty of creating an effective fingerprint dating model, especially with a narrow period of accuracy.

指纹是犯罪现场常见的法医证据。除了广泛用于人类身份识别之外，它们还可以用于约会，为刑事调查提供信息。尽管这种方法可以获得巨大的收益，但目前还没有可靠的分析方法来估计指纹的年龄。老化是一个复杂的、不受控制的过程，其变化受时间和环境条件等因素的影响。本研究试图利用偏最小二乘法判别分析（PLS-DA）的化学计量学工具，评估利用近红外高光谱图像（NIR-HSI）测定指纹年代的可能性。研究人员对6名志愿者的指纹进行了为期8周的分析，并将这段时间划分为不同的时间间隔，以便进一步分类。结果得到了三种PLS-DA模型：第一种有8个类，第二种有4个类，最后一种只有2个类。在第一个模型中，5.56%的预测样本被正确分类，而在第二个模型中，成功率为30.56%，第三个模型的成功率为63.89%。这突出了创建一个有效的指纹测年模型的困难，特别是在一个狭窄的准确度时期。

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引用次数: 0

Synthesis and isotopic characterization of 1,3,5-trinitroso-1,3,5-triazine (R-Salt) 1,3,5-三硝基-1,3,5-三嗪（R-Salt）的合成及同位素表征

IF 2.2 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2025-10-25 DOI: 10.1016/j.forc.2025.100706

Yinghua Wang , Tony Peter , James F. Carter

Hexamine is a precursor chemical for commercial explosives such as RDX and HMX and homemade explosive such as HMTD and R-Salt. Although now controlled in some jurisdictions, hexamine was still available in Australia in the form of solid fuel tablets. The other ingredient of R-Salt, sodium nitrite, was available with few restrictions.

We report the isotopic compositions of hexamine derived from solid fuel tablets and sodium nitrite available in 2024. The isotopic compositions for 18 samples of hexamine spanned wider ranges than previously reported: δ²H from −179 to +104 ‰, δ¹³C from −49.7 to −25.0 ‰ and δ¹⁵N from −6.5 to +3.7 ‰. The nitrogen isotopic compositions of 17 samples of sodium nitrite ranged from −166.9 to +3.1 ‰ representing some of the most ¹⁵N depleted values reported for natural materials.

32 batches of R-Salt were synthesised from selected samples of hexamine and sodium nitrite. Progressing from hexamine to R-Salt, δ²H values became more positive by between +5.2 and + 18 ‰ and δ¹³C values became more positive by between +12.3 and + 14.6 ‰. A combination of these data presents a means to associate samples of R-Salt with precursor hexamine.

The contributions of hexamine and sodium nitrite to the nitrogen isotopic compositions of R-Salt were combined by a simple mass-balance equation. Using this model the δ¹⁵N values of R-Salt were more negative than the combined precursors by between −2.0 and − 1.1 ‰. This presents an additional means to associate samples of R-Salt with both precursor chemicals.

Hexamine是商用炸药（如RDX和HMX）和自制炸药（如HMTD和R-Salt）的前体化学品。虽然现在在一些司法管辖区受到控制，但在澳大利亚仍然可以以固体燃料片剂的形式获得。r -盐的另一种成分亚硝酸钠几乎没有限制。我们报告了2024年从固体燃料片和亚硝酸钠中提取的氢的同位素组成。18个样品的同位素组成范围比以往报道的更宽：δ2H在−179 ~ +104‰，δ13C在−49.7 ~−25.0‰，δ15N在−6.5 ~ +3.7‰。17个亚硝酸钠样品的氮同位素组成范围在- 166.9 ~ +3.1‰之间，代表了一些天然材料中最具15N耗尽值。以亚硝酸钠为原料，合成了32批R-Salt。从hexamine到R-Salt， δ2H值增加了+5.2 ~ + 18‰，δ13C值增加了+12.3 ~ + 14.6‰。这些数据的组合提供了一种将R-Salt样品与前体hexamine相关联的方法。用一个简单的质量平衡方程结合了亚硝酸钠和亚硝酸钠对r -盐氮同位素组成的贡献。在此模型下，R-Salt的δ15N值比组合前驱体负- 2.0 ~ - 1.1‰。这提供了另一种将R-Salt样品与两种前体化学品相关联的方法。

{"title":"Synthesis and isotopic characterization of 1,3,5-trinitroso-1,3,5-triazine (R-Salt)","authors":"Yinghua Wang , Tony Peter , James F. Carter","doi":"10.1016/j.forc.2025.100706","DOIUrl":"10.1016/j.forc.2025.100706","url":null,"abstract":"<div><div>Hexamine is a precursor chemical for commercial explosives such as RDX and HMX and homemade explosive such as HMTD and R-Salt. Although now controlled in some jurisdictions, hexamine was still available in Australia in the form of solid fuel tablets. The other ingredient of R-Salt, sodium nitrite, was available with few restrictions.</div><div>We report the isotopic compositions of hexamine derived from solid fuel tablets and sodium nitrite available in 2024. The isotopic compositions for 18 samples of hexamine spanned wider ranges than previously reported: <em>δ</em><sup>2</sup>H from −179 to +104 ‰, <em>δ</em><sup>13</sup>C from −49.7 to −25.0 ‰ and <em>δ</em><sup>15</sup>N from −6.5 to +3.7 ‰. The nitrogen isotopic compositions of 17 samples of sodium nitrite ranged from −166.9 to +3.1 ‰ representing some of the most <sup>15</sup>N depleted values reported for natural materials.</div><div>32 batches of R-Salt were synthesised from selected samples of hexamine and sodium nitrite. Progressing from hexamine to R-Salt, <em>δ</em><sup>2</sup>H values became more positive by between +5.2 and + 18 ‰ and <em>δ</em><sup>13</sup>C values became more positive by between +12.3 and + 14.6 ‰. A combination of these data presents a means to associate samples of R-Salt with precursor hexamine.</div><div>The contributions of hexamine and sodium nitrite to the nitrogen isotopic compositions of R-Salt were combined by a simple mass-balance equation. Using this model the <em>δ</em><sup>15</sup>N values of R-Salt were more negative than the combined precursors by between −2.0 and − 1.1 ‰. This presents an additional means to associate samples of R-Salt with both precursor chemicals.</div></div>","PeriodicalId":324,"journal":{"name":"Forensic Chemistry","volume":"46 ","pages":"Article 100706"},"PeriodicalIF":2.2,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474201","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}

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