Forensic Chemistry最新文献_第4页

Development and evaluation of a nontargeted electrochemical surface-enhanced Raman spectroscopy (EC-SERS) screening method applied to forensic seized drug casework samples 开发和评估应用于法医缉获毒品案件样本的非靶向电化学表面增强拉曼光谱（EC-SERS）筛查方法

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-10 DOI: 10.1016/j.forc.2024.100621

Colby E. Ott , Alexis Wilcox , Sharon Kalb , Amber McConnell , Edward Sisco , Luis E. Arroyo

Screening tests in forensic laboratories are a critical step in ensuring an efficient and effective analytical scheme for presumptive identification. Electrochemical surface-enhanced Raman spectroscopy (EC-SERS) represents a novel workflow that can be applied both in the laboratory and on-site as a fast, inexpensive, and selective approach to seized drug screening. Using cyclic voltammetry and a 785 nm Raman spectrometer, a nontargeted screen was developed using silver screen-printed electrodes and tested on a panel of common drugs of abuse and adulterants. Following characterization of the analyte panel, in-house binary and tertiary mixtures were assessed and the effectiveness of the developed EC-SERS method was tested using common score-based algorithms including correlation, hit-quality-index, spectral angle mapper, and correlation of the 1st derivative. For in-house blind samples, this approach allowed for positive identification of at least one compound in 100 % of samples. Identification of all compounds was lower at 52 %. Seized drug samples from adjudicated casework were tested on-site at the Maryland State Police laboratory as a fit-for-purpose study. EC-SERS provided an accurate screening result of 86 % using the 1st derivative correlation. Applying knowledge of both the local drug landscape and the prevalence of specific adulterants, this value improved to a positive screening of 93 % for the authentic samples. EC-SERS represents a novel approach to drug screening that could impact forensic laboratories, customs and border patrol, public health, and scene investigations. Future work should focus on improved data processing and chemometric tools for data generated in EC-SERS methods.

法医实验室的筛选测试是确保推定鉴定分析方案高效和有效的关键步骤。电化学表面增强拉曼光谱（EC-SERS）是一种新颖的工作流程，既可用于实验室，也可用于现场，是一种快速、廉价且具有选择性的缴获毒品筛查方法。利用循环伏安法和 785 nm 拉曼光谱仪，使用银丝网印刷电极开发了一种非靶向筛查方法，并对一组常见的滥用药物和掺杂物进行了测试。在对分析物进行表征后，对内部二元和三元混合物进行了评估，并使用常见的基于评分的算法（包括相关性、命中质量指数、光谱角度映射器和 1 次导数的相关性）对所开发的 EC-SERS 方法的有效性进行了测试。对于内部盲样，这种方法可以在 100% 的样品中鉴定出至少一种化合物。所有化合物的鉴定率较低，仅为 52%。作为一项适用性研究，马里兰州警察局实验室对从已判决的案件中缉获的毒品样本进行了现场检测。使用 1 次导数相关性，EC-SERS 提供了 86% 的准确筛选结果。利用对当地毒品状况和特定掺杂物流行情况的了解，这一数值提高到了 93%，对真实样本的筛查结果呈阳性。EC-SERS 是一种新型的毒品筛查方法，可对法医实验室、海关和边境巡逻、公共卫生和现场调查产生影响。未来的工作重点应该是改进 EC-SERS 方法所产生数据的数据处理和化学计量学工具。

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引用次数: 0

Observation of chromatographic differences by non-specialist viewers for one-dimensional gas chromatography and comprehensive two-dimensional gas chromatography output 非专业人员观察一维气相色谱和综合二维气相色谱输出的色谱差异

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-09 DOI: 10.1016/j.forc.2024.100620

Clarissa Camara , Cynthia Cheung , Katelynn A. Perrault Uptmor

In the context of forensic investigations, chromatography is used to characterize a sample’s components, providing a chemical pattern to compare with known references which is often presented to individuals without specialized training in analytical chemistry. Comprehensive two-dimensional gas chromatography (GC×GC) has recently become popular in forensic research for analyzing samples such as fire debris samples, drugs, chemical threats, human remains detection, and more. New methods are developed in forensic research regularly, which challenge our view of what may be increasingly complex to convey through scientific communication. This study investigated individuals’ ability to observe differences in images for non-chromatographic photographs, one-dimensional gas chromatography (GC) chromatograms, and comprehensive two-dimensional gas chromatography (GC×GC) contour plots. The goal was to identify whether comparative observations between two outputs were facilitated or hindered when observing GC chromatograms compared to GC×GC contour plots, using photographs as a control. Participants indicated low difficulty in finding differences between pairs of images in all categories. They scored highly at indicating when two images were distinguishable or indistinguishable, with no significant difference between control images and each category. These results support that GC×GC output can be implemented in expert testimony without challenges over traditional one-dimensional techniques. Ongoing research should avoid statements that GC×GC may facilitate or hinder juror comprehension, as the results currently indicate no significant benefit or drawback. Additional research is needed to improve understanding of how technique explanation could aid expert witness testimony to better evaluate how this increasingly common technique will fit into future forensic casework opportunities.

在法医调查中，色谱法被用来描述样品成分的特征，提供化学模式与已知参照物进行比较，这通常会呈现给没有受过分析化学专业培训的人。综合二维气相色谱法（GC×GC）最近在法医研究中非常流行，用于分析火灾残骸样本、毒品、化学威胁、人体遗骸检测等样本。法医学研究中经常会开发出新的方法，这对我们的观点提出了挑战，因为通过科学交流传达的信息可能会越来越复杂。本研究调查了个人观察非色谱照片、一维气相色谱（GC）色谱图和综合二维气相色谱（GC×GC）等高线图的图像差异的能力。目的是以照片为对照，确定在观察气相色谱色谱图与气相色谱×气相色谱等值线图时，两种输出结果之间的比较观察是有利还是有碍。参与者表示，在所有类别中发现成对图像之间的差异的难度都很低。他们在指出两幅图像可区分或不可区分方面得分很高，而对照图像与每个类别之间没有显著差异。这些结果证明，与传统的一维技术相比，GC×GC 输出可以在专家证词中使用，而不会遇到挑战。正在进行的研究应避免关于 GC×GC 可能会促进或阻碍陪审员理解的说法，因为目前的结果并未显示出明显的益处或弊端。还需要进行更多的研究，以更好地理解技术解释如何帮助专家证人作证，从而更好地评估这种日益普遍的技术将如何适应未来的法医办案机会。

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引用次数: 0

Assessment of two benzylation strategies for the analysis of nerve-agent derived ethyl- and pinacolyl methyl phosphonic acids in sandy loam soil by GC–MS 利用气相色谱-质谱法分析沙质壤土中神经毒剂衍生的乙基和频哪醇甲基膦酸的两种苄基化策略评估

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-06 DOI: 10.1016/j.forc.2024.100616

Vidia A. Gokool , Alexander K. Vu , Saphon Hok , Carlos A. Valdez

Despite their prohibition by the Chemical Weapons Convention, nerve agents (NAs) remain in use against military and civilian targets. Due to their high reactivity, NAs readily degrade to phosphonic acids, making them important markers in the inspection of areas of presumed NA use. In this work, we assess the use of benzylation to modify ethyl- and pinacolyl methylphosphonic acids, degradation products of VX and Soman respectively, for their efficient detection in a soil matrix at ∼10 and ∼1 μg/g using GC–MS. The soil matrix, Sandy Loam (SL), was chosen for its ubiquitous nature, complex composition with silica particles embedded in clay, and low organic content. In this study, we demonstrate that benzylation via benzyl bromide yields a LOD = 25.6 ng/mL for benzylated-EMPA and LOD = 30.1 ng/mL for benzylated-PMPA. This is superior to the use of p-methoxybenzyl trichloroacetimidate in providing stable phosphonic acid ester derivatives for analysis. A base-modified procedure for p-methoxybenzylation was explored in this study yielding a LOD = 29.1 ng/mL for p-methoxybenzylated-EMPA and LOD = 39.8 ng/mL for p-methoxybenzylated-PMPA. Both benzylation pathways (benzyl bromide and p-methoxybenzyl trichloroacetimidate) can be used to yield phosphonic acid derivatives that provide further confirmation of these Soman and VX degradation products in soil samples in investigative scenarios. The work herein represents the first application of benzylation methods for the analysis of these NA markers in the acidic, silicon-based SL soil.

尽管《化学武器公约》禁止使用神经毒剂，但神经毒剂仍被用于攻击军事和民用目标。由于其反应活性高，NAs 很容易降解为膦酸，这使其成为检查假定使用过 NA 的区域的重要标记。在这项工作中，我们评估了利用苄基化对乙基甲基膦酸和频哪醇甲基膦酸（分别为 VX 和索曼的降解产物）进行改性的方法，以便利用气相色谱-质谱法在土壤基质中有效检测出 10 ∼ μg/g 和 1 ∼ μg/g 的甲基膦酸。选择砂质壤土（Sandy Loam，SL）作为土壤基质是因为它无处不在，成分复杂，粘土中含有二氧化硅颗粒，而且有机物含量较低。在这项研究中，我们证明了通过苄基溴进行苄基化，苄基化-EMPA 的 LOD = 25.6 ng/mL，苄基化-PMPA 的 LOD = 30.1 ng/mL。这比使用对甲氧基苄基三氯乙酰亚氨酸来提供稳定的膦酸酯衍生物进行分析更有优势。本研究探索了对甲氧基苄基化的碱修饰程序，结果显示对甲氧基苄基化-EMPA 的检测限为 29.1 纳克/毫升，对甲氧基苄基化-PMPA 的检测限为 39.8 纳克/毫升。这两种苄基化途径（苄基溴和对甲氧基苄基三氯乙酰亚氨酸）都可用于生成膦酸衍生物，从而进一步确认调查场景中土壤样本中的这些索曼和 VX 降解产物。本研究首次将苄基化方法用于分析酸性硅基 SL 土壤中的这些 NA 标记物。

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引用次数: 0

Portable near-infrared detection to replace color tests in an analytical scheme for forensic drug identification 在法医鉴定毒品的分析方案中，用便携式近红外检测仪取代颜色检测仪

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-06 DOI: 10.1016/j.forc.2024.100615

Annique van Beek , Laura I. Stuyver , Henk-Jan Ramaker , Emile M. Mes , Arian C. van Asten , Ruben F. Kranenburg

In the ever-changing drug market the popularity and availability of substances is dynamic. In the Netherlands, ketamine and various cathinones have recently seen increased prevalence. It is crucial for law enforcement to quickly obtain an initial indication of the identity of a substance. This first test also serves as quality control for subsequent confirmation with GC–MS analysis. Traditionally, color tests have been used for these purposes. While these tests are quick and inexpensive, they have the disadvantage of reacting only to a few traditional drugs. Suitable color tests are not available for many new psychoactive substances (NPS). Near-infrared (NIR) spectroscopy is a rapid technique that provides a characteristic spectrum for organic compounds. This technique is more versatile than color tests and can adapt more quickly to market changes by incorporating reference spectra into the library. This study demonstrates the feasibility of obtaining a good quality NIR spectrum from a 20 mg sub-sample in a test tube. This was achieved by scanning the test tube through the glass bottom. In the routine analytical scheme, these test tubes were subsequently batchwise analyzed by GC–MS. From the NIR spectra, 84 % true positive and 100 % true negative results were achieved on 516 casework samples, including identification of substances without available color tests like ketamine. Missed false negatives primarily involved new substances absent from the library, emphasizing the need for continuous library updates. NIR’s adaptability to market changes is crucial, allowing the inclusion of new substances as they emerge. This method enhances law enforcement’s ability to make informed decisions, aiding in the indictment process.

在瞬息万变的毒品市场中，毒品的流行和供应是动态变化的。在荷兰，氯胺酮和各种卡西酮最近越来越流行。对于执法部门来说，快速获得某种物质的初步特征至关重要。首次检测也可作为后续气相色谱-质谱分析确认的质量控制。传统上，这些用途一直使用颜色测试。虽然这些检测方法快速而廉价，但其缺点是只能对少数传统药物产生反应。许多新型精神活性物质 (NPS) 都没有合适的颜色测试。近红外光谱（NIR）是一种快速技术，可提供有机化合物的特征光谱。与颜色测试相比，该技术用途更广，而且通过将参考光谱纳入库，可以更快地适应市场变化。本研究证明了从试管中的 20 毫克子样品中获取高质量近红外光谱的可行性。这是通过玻璃底部扫描试管实现的。在常规分析方案中，这些试管随后通过气相色谱-质谱（GC-MS）进行批量分析。通过近红外光谱分析，516 个案例样本中的阳性结果占 84%，阴性结果占 100%，其中包括对氯胺酮等无法进行颜色测试的物质的鉴定。漏检的假阴性物质主要是库中没有的新物质，这强调了持续更新库的必要性。近红外技术对市场变化的适应性至关重要，可以在新物质出现时将其纳入。这种方法提高了执法部门做出明智决定的能力，有助于起诉过程。

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引用次数: 0

Enhancing Counterfeit Banknote Analysis: Case Studies Using TOF-SIMS 加强伪钞分析：使用 TOF-SIMS 的案例研究

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-03 DOI: 10.1016/j.forc.2024.100617

Alice Bejjani , Raymond Tannous , Georges Chalhoub , Mazen Hamdan , Bilal Nsouli

Counterfeiting banknotes poses a significant threat to economies worldwide, particularly in developing countries where cash transactions remain predominant. Despite advancements in security features, counterfeiters continue to adapt, necessitating more sophisticated analysis methods. Time of flight Secondary Ion Mass Spectrometry (TOF-SIMS) offers a powerful approach to surface chemical imaging and depth profiling of counterfeit currencies. Real cases of five different counterfeit Lebanese banknotes are studied, using TOF-SIMS to address specific questions regarding the composition and placement of replicated security features, gaining insights into counterfeit banknote production and the raw materials used. The findings provide essential information to decision-makers at the national bank, supporting the design of future currencies through the selection of security features best suited to the local market, thereby enhancing protection against financial fraud..

伪造钞票对全球经济构成重大威胁，尤其是在现金交易仍占主导地位的发展中国家。尽管防伪功能不断进步，但伪造者仍在不断调整，因此需要更复杂的分析方法。飞行时间二次离子质谱法（TOF-SIMS）为伪造货币的表面化学成像和深度剖析提供了一种强大的方法。研究了五种不同的黎巴嫩伪钞的真实案例，利用 TOF-SIMS 解决了有关复制防伪特征的成分和位置的具体问题，深入了解了伪钞的生产和所使用的原材料。研究结果为国家银行的决策者提供了重要信息，通过选择最适合当地市场的防伪特征来支持未来货币的设计，从而加强对金融欺诈的防范。

引用次数: 0

Halogen-bond mediated charge transfer for visual competitive colorimetric detection of fentanyl 卤素键介导的电荷转移用于芬太尼的视觉竞争性比色检测

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-03 DOI: 10.1016/j.forc.2024.100618

Boyan Li , Qiongyao Ning , Wenyou Ye , Qianxi Wang , Haili Yu , Xuecheng Chen , Yi He

Colorimetric assays are inexpensive and attractive tools for the detection of fentanyl (FTN), yet further enhancing their sensitivity remains a major challenge. Herein, we develop a halogen-bond mediated visual competitive colorimetric assay for FTN using Erythrosine B (EB) as a probe. The addition of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide (F-127) induces the EB aggregation, strongly suppressing the background signal. Upon the introduction of FTN, the subsequent competitive reaction displaces F-127 to generate EB-FTN charge-transfer complexes via N^…I halogen bonds between electron-rich amine groups and electron-deficient iodine sites, accompanying a significant absorbance wavelength shift and pink-to-purple color change. The limits of detection of this approach for FTN are 2 mg·L⁻¹ by the naked eye and 0.19 mg·L⁻¹ by UV–vis spectroscopy, which are approximately 3.7-fold to 4 orders of magnitude more sensitive than the reported colorimetric assays. Meanwhile, the present method is well applied for FTN-spiked domestic sewage samples, and an easy-to-use smartphone-based digital image colorimetry is also fabricated. It is expected that such an assay can play a key role in alleviating the worldwide opioid overdose crisis.

比色测定法是检测芬太尼（FTN）的廉价而有吸引力的工具，但进一步提高其灵敏度仍是一项重大挑战。在此，我们以赤藓红 B（EB）为探针，开发了一种卤素键介导的视觉竞争比色法检测 FTN。加入聚（环氧乙烷）-块状-聚（环氧丙烷）-块状-聚（环氧乙烷）（F-127）可诱导 EB 聚合，从而强烈抑制背景信号。引入 FTN 后，随后的竞争反应会置换 F-127，通过富电子胺基团和缺电子碘位点之间的 N...I 卤素键生成 EB-FTN 电荷转移复合物，伴随着显著的吸光波长偏移和粉红色到紫色的颜色变化。这种方法对芴甲氧羰基的检测限为肉眼 2 mg-L-1，紫外可见光谱 0.19 mg-L-1，比已报道的比色法灵敏度高出约 3.7 倍至 4 个数量级。同时，本方法还能很好地应用于添加了 FTN 的生活污水样品，并制作了一种易于使用的基于智能手机的数字图像比色法。这种检测方法有望在缓解全球阿片类药物过量危机方面发挥关键作用。

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引用次数: 0

Use of optimized 1H selTOCSY for identification and individualization of petrol samples from fire debris 使用优化的 1H selTOCSY 对火灾残骸中的汽油样本进行识别和个性化处理

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-11-01 DOI: 10.1016/j.forc.2024.100614

Yanita Yankova , John Warren , Michael D. Cole , Silvia Cirstea

Detection and identification of ignitable liquids in fire investigation is ongoing challenge for forensics investigators. This study uses the analytical power of NMR analysis and permits the identification of trace amounts of olefinic compounds the complex mixture of petrol that aids the individualization of petrol sources. The ¹H selTOCSY NMR method has proven to be successful in the investigation of the four sets of alkenes namely: 3-methyl-1-butene (set 1), a mixture of 3-methyl-1-butene and 1-pentene (set 2), 2-methyl-2-butene (set 3) and a mixture of cis and trans-2-pentene (set 4) in petrol samples evaporated to different extents, simulating the action of weathering of actual casework samples, and still achieved significant discrimination of petrol brands at 25 % and 50 % evaporation. Discrimination of burned samples also proved possible, both of burnt petrol its own and then petrol burned on different substrates including wood, carpet, fabric, and paper materials representing common household fire debris residues. ¹H selTOCSY NMR experiments on these alkene signals remove most of the non-alkene-related signals from the spectra and thus provide additional clarity in heavily burnt and contaminated samples, increasing the capacity to discriminate between samples using the four alkene markers.

在火灾调查中检测和识别可燃液体是法医调查人员一直面临的挑战。本研究利用核磁共振分析的分析能力，对汽油复杂混合物中的痕量烯烃化合物进行鉴定，从而帮助确定汽油来源。事实证明，1H selTOCSY NMR 方法在研究以下四组烯烃方面取得了成功：在汽油样品中，3-甲基-1-丁烯（第 1 组）、3-甲基-1-丁烯和 1-戊烯的混合物（第 2 组）、2-甲基-2-丁烯（第 3 组）以及顺式和反式-2-戊烯的混合物（第 4 组）的蒸发程度不同，模拟了实际案例样品的风化作用，在蒸发 25% 和 50% 的情况下，仍能显著区分汽油品牌。事实证明，还可以对燃烧过的样品进行区分，包括燃烧过的汽油本身和在不同基质上燃烧过的汽油，这些基质包括木材、地毯、织物和代表常见家庭火灾残留物的纸质材料。对这些烯信号进行的 1H selTOCSY NMR 实验消除了光谱中大部分与烯无关的信号，从而使严重燃烧和污染的样品更加清晰，提高了使用四个烯标记对样品进行鉴别的能力。

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引用次数: 0

Detection of synthetic cathinones in seized drugs using surface-enhanced Raman spectroscopy (SERS) 利用表面增强拉曼光谱（SERS）检测缉获药物中的合成卡西酮类化合物

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-10-28 DOI: 10.1016/j.forc.2024.100613

Mario O. Vendrell-Dones, Emily Hernandez, Sevde Dogruer Erkok, Bruce McCord

There is need for a screening method to assist authorities in detecting cathinone analogs in a rapid, reliable, and sensitive fashion. This work describes the development of Ag colloidal systems for use as SERS-enhancing substrates to detect six synthetic cathinone analogs. Furthermore, specific interactions between the analyte and metal surface were probed by determining the effect of functional groups attached to the core synthetic cathinone. Initial work involved Density Functional Theory (DFT) calculations at B3LYP/6-311G** level to predict Raman frequencies of the studied compounds. Normal Raman measurements on dried solid residues of synthetic cathinone standards were next examined, and the resulting scaled spectra were used to ensure concordance of the DFT-predicted frequencies with experimental values. Subsequent work focused on the development of a SERS protocol, which included the selection of nanoparticles in solution, followed by the addition of aggregating agents such as MgCl₂ and KBr to produce high-density hot-spots on the nanometallic surface. Sample treatment conditions necessary to detect the selected synthetic cathinone analogs were also optimized. Once completed, the characterization and identification of the main peaks that make up the synthetic cathinone core structure were assigned and unique functional groups for each of the analogs were identified. Overall, the analytical process takes less than a minute, making the procedure useful for field screening. Ultimately, this procedure can aid law enforcement and first responders by providing a more specific method for rapid and sensitive on-site analysis of seized drugs.

需要一种筛选方法来协助有关部门以快速、可靠和灵敏的方式检测卡西酮类似物。这项工作描述了开发银胶体系统作为 SERS 增强底物来检测六种合成卡西酮类似物的情况。此外，还通过确定附着在核心合成卡西酮上的官能团的影响，探究了分析物与金属表面之间的特定相互作用。最初的工作包括在 B3LYP/6-311G** 水平上进行密度泛函理论（DFT）计算，以预测所研究化合物的拉曼频率。接下来，对合成卡西酮标准的干燥固体残留物进行了正常拉曼测量，并使用由此产生的缩放光谱来确保 DFT 预测频率与实验值一致。随后的工作重点是开发 SERS 方案，包括选择溶液中的纳米粒子，然后加入 MgCl2 和 KBr 等聚集剂，在纳米金属表面产生高密度热点。此外，还对检测所选合成卡西酮类似物所需的样品处理条件进行了优化。完成后，对构成合成卡西酮核心结构的主峰进行了特征描述和鉴定，并确定了每种类似物的独特官能团。总体而言，分析过程耗时不到一分钟，因此可用于现场筛选。最终，该程序可以帮助执法人员和急救人员，为快速灵敏地现场分析缉获的毒品提供更具体的方法。

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引用次数: 0

Development and validation of a forensic workflow for the complete profiling of illicit drugs and excipients 开发和验证用于非法药物和辅料完整特征分析的法医工作流程

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-10-18 DOI: 10.1016/j.forc.2024.100612

Mikaela J. Radke, Alan White, Wendy A. Loughlin, Sarah L. Cresswell

The development of a complete understanding of the societal harms of illicit drug mixtures requires a greater emphasis on the complete identification of illicit and excipient compounds. To increase the feasibility of this in practice, common and emerging analytical techniques were examined in the context of developing a non-targeted forensic workflow. The purpose of this workflow was to increase the identification of excipient compounds without compromising the quality of illicit drug identification as required for admissibility of evidence in court. This incorporated the testing of simulated compound mixtures to develop the principal avenues of analysis. These pathways were then validated through the testing of unknown compound mixtures. The techniques of focus included GCMS, FTIR, LC-HRMS for identification, and LC-HRMS for quantitation. These techniques were organised into their respective categories of techniques, according to the SWGDRUG guidelines, to produce a workflow that would ensure the admissibility of evidence no matter the pathway taken. HRMS was examined as an emerging technique not currently used in illicit drug analysis facilitating non-targeted analysis pathways. From this, and in combination with GCMS, all organic components were identifiable in simulated and unknown mixtures. Partial identification was also achieved for insoluble compounds using FTIR analysis. Identification by HRMS was facilitated by comparison to reference standards and MS/MS spectra matching to the high-resolution database MzCloud. This demonstrated the applicability of HRMS, specifically the Exploris 120 Orbitrap, to the identification and quantitation of both illicit and organic excipient compounds within Forensic Chemistry.

要全面了解非法药物混合物的社会危害，就必须更加重视非法化合物和辅料化合物的全面鉴定。为了提高这种做法在实践中的可行性，在开发非目标法医学工作流程的背景下，对常见的和新兴的分析技术进行了研究。该工作流程的目的是在不影响非法药物鉴定质量的情况下，提高辅料化合物的鉴定率，这也是法庭采纳证据的要求。其中包括对模拟化合物混合物进行测试，以开发主要的分析途径。然后通过测试未知化合物混合物来验证这些途径。重点技术包括 GCMS、FTIR、用于鉴定的 LC-HRMS 和用于定量的 LC-HRMS。根据 SWGDRUG 指南，这些技术被归入各自的技术类别，以形成一个工作流程，确保无论采用哪种途径，证据都具有可采性。HRMS 作为一种目前尚未用于非法药物分析的新兴技术，为非目标分析途径提供了便利。由此，结合 GCMS，可以识别模拟和未知混合物中的所有有机成分。利用傅立叶变换红外分析法还对不溶性化合物进行了部分鉴定。通过与参考标准的比较以及与高分辨率数据库 MzCloud 的 MS/MS 光谱匹配，促进了 HRMS 的鉴定。这表明 HRMS（特别是 Exploris 120 Orbitrap）适用于法医化学中非法和有机辅料化合物的鉴定和定量。

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引用次数: 0

Recovery and detection of ignitable liquid residues from the substrates by solid phase microextraction – direct analysis in real time mass spectrometry 通过固相微萃取--实时质谱直接分析--回收和检测底物中的可燃液体残留物

IF 2.6 3区医学 Q2 CHEMISTRY, ANALYTICAL

Forensic Chemistry

Pub Date : 2024-10-18 DOI: 10.1016/j.forc.2024.100611

Shruthi Perna , Ngee Sing Chong , Mengliang Zhang

In this study, direct analysis in real time mass spectrometry (DART-MS) was coupled to the solid phase microextraction (SPME) to extract and analyze the ignitable liquid residues (ILR) present in the sample matrices. The SPME extraction parameters, such as extraction temperature and extraction time, were optimized using a two-factor central composite design. The SPME-DART-MS setup was utilized to analyze the substrates and fire debris matrices spiked with gasoline. The results indicate that the less volatile marker compounds from gasoline were recovered from the substrates and fire debris, and their profiles matched well with the gasoline liquid samples analyzed directly by DART-MS. As expected, the effective extraction of marker compounds in gasoline required a relatively high temperature, i.e., 150 ℃. In the presence of a matrix, a higher extraction temperature and longer extraction time could benefit the extraction efficiency. The desorption of ILR on SPME fiber was performed by inserting the fiber into the DART-MS helium gas stream at 300 ℃ for 1 min with no carry-over residues being observed between successive samples. The chemical information attained with this method is typically not observed in the current GC/MS-based practice. The SPME-DART-MS was also extended to reanalyze less volatile components of ILR on substrates after the ASTM E1412 activated charcoal method, which indicates its possible application subsequent to the traditional GC/MS ILR analysis. The SPME-DART-MS has shown promise in ILR detection as an important complementary tool.

本研究将直接分析实时质谱法（DART-MS）与固相微萃取法（SPME）相结合，对样品基质中的可燃液体残留物（ILR）进行萃取和分析。采用双因素中心复合设计优化了 SPME 的萃取参数，如萃取温度和萃取时间。利用 SPME-DART-MS 装置对添加了汽油的基质和火灾残骸基质进行了分析。结果表明，从基质和火灾残骸中回收到了挥发性较低的汽油标记化合物，而且其特征与直接用 DART-MS 分析的汽油液体样品十分吻合。正如预期的那样，有效萃取汽油中的标记化合物需要相对较高的温度，即 150 ℃。在存在基质的情况下，更高的萃取温度和更长的萃取时间会提高萃取效率。将 SPME 纤维插入 300 ℃ 的 DART-MS 氦气流中 1 分钟，即可解吸 SPME 纤维上的 ILR，且在连续样品之间观察不到携带残留物。这种方法所获得的化学信息通常是目前基于气相色谱/质谱法所无法观察到的。在使用 ASTM E1412 活性炭法之后，SPME-DART-MS 还可用于重新分析基质上挥发性较低的 ILR 成分，这表明它可以在传统的 GC/MS ILR 分析之后继续使用。作为一种重要的补充工具，SPME-DART-MS 在检测 ILR 方面已显示出良好的前景。

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引用次数: 0