Combined Collection and Analysis of Inorganic and Organic Gunshot Residues

Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid^® ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method.     

三七破壁饮片质量分析

目的 建立三七破壁饮片的质量控制方法。方法 参考2015年版《中华人民共和国药典》相关检测方法，对10批三七破壁饮片的性状、显微特征、薄层鉴别、指纹图谱及其水分、灰分、浸出物、重金属、粒径分布以及人参皂苷Rb1、人参皂苷Rg1、三七皂苷R1的含量等进行检测，建立三七破壁饮片的质量控制方法。结果 三七破壁饮片为灰褐色至灰黄色的颗粒，气微，味苦回甜。显微镜下可见淀粉粒甚多，单粒圆形、半圆形或圆多角形，直径4~30 μm，脂道碎片含黄色分泌物，导管碎片较少。薄层鉴别显示，10批样品在与对照品色谱相应的位置上，均显示相同颜色的斑点。水分范围为5.05%～9.82%，总灰分范围为2.96%～3.20%，酸不溶性灰分范围为0.52%～1.19%，浸出物含量范围为21.03%～27.78%，每0.01 g样品中未破壁细胞数为46~81。指纹图谱显示，各批次三七破壁饮片的色谱图相似度为0.879~0.996。粒径分析显示，各样品D90为34.09~38.93 μm。10批样品中人参皂苷Rg1、人参皂苷Rb1、三七皂苷R1总含量为6.9%～8.3%。结论 建立的方法可用于三七破壁饮片的质量控制。     

超高效液相色谱法比较鲜川芎和 川芎药材中6种成分含量

目的 采用超高效液相色谱法(ultra-high performance liquid chromatography, UPLC)比较鲜川芎和川芎药材中6种活性成分(川芎嗪、阿魏酸、洋川芎内酯I、洋川芎内酯H、洋川芎内酯A、藁本内酯)的含量差异，为该药材的产地加工提供实验依据。方法 采用75%甲醇超声提取，UPLC测定鲜川芎和川芎药材中6种活性成分，根据样品处理条件计算质量分数并进行比较。流动相为乙腈(A)-0.1%甲酸水溶液(B)，梯度洗脱，流速为0.2 mL/min，检测波长为294 nm，柱温30 ℃，进样体积2 μL。结果 经检测，阿魏酸、藁本内酯、洋川芎内酯A为鲜川芎和川芎药材的共有成分，鲜川芎中未检测到洋川芎内酯I及洋川芎内酯H。鲜川芎样品中各成分的质量分数为阿魏酸0.003 9%、洋川芎内酯A 0.006 4%、藁本内酯0.54%；川芎药材中各成分的质量分数为阿魏酸0.088%、洋川芎内酯I 0.20%、洋川芎内酯H 0.031%、洋川芎内酯A 0.76%、藁本内酯 1.3%。结论 川芎药材与鲜川芎中化学成分存在差异，推测在川芎的产地加工及贮藏过程中存在成分的转化。     

血府逐瘀汤辅助治疗重症闭合性胸外伤临床观察

目的 观察血府逐瘀汤辅助治疗重症闭合性胸外伤的疗效。方法 将60例重症闭合性胸外伤患者随机分为治疗组和对照组，每组30例。对照组在西医常规对症治疗的基础上进行纤维气管镜肺泡灌洗，治疗组在对照组疗法的基础上加服血府逐瘀汤。采用视觉模拟量表(visual analogue scale，VAS)评价患者的胸痛程度，通过检测外周血白细胞(white blood cell, WBC)及血清C-反应蛋白(C-reactive protein, CRP)水平评价炎症程度，采用血气分析评价肺通气和换气功能。结果 治疗组患者治疗后VAS评分降低程度显著大于对照组（P<0.05）。治疗组患者住院时间较对照组明显缩短（P<0.05）。治疗第3、7、12天末，治疗组患者血pH值、动脉血氧分压、血氧饱和度均显著高于对照组（P<0.05），动脉血二氧化碳分压、外周血WBC计数、血清CRP水平均显著低于对照组（P<0.05）。治疗组临床疗效明显优于对照组（P<0.05）。结论 血府逐瘀汤能提高重症闭合性胸外伤患者肺泡的通透性，改善肺组织的通气及换气功能，降低炎症反应。     

Organic impurity profiling of fentanyl samples associated with recent clandestine laboratory methods

Nearly a decade ago, fentanyl reappeared in the United States illicit drug market. In the years since, overdose deaths have continued to rise as well as the amount of fentanyl seized by law enforcement agencies. Research surrounding fentanyl production has been beneficial to regulatory actions and understanding illicit fentanyl production. In 2017, the Drug Enforcement Administration (DEA) began collecting seized fentanyl samples from throughout the United States to track purity, adulteration trends, and synthetic impurity profiles for intelligence purposes. The appearance of a specific organic impurity, phenethyl-4-anilino-N-phenethylpiperidine (phenethyl-4-ANPP) indicates a shift in fentanyl production from the traditional Siegfried and Janssen routes to the Gupta-patent route. Through a collaboration between the DEA and the US Army's Combat Capabilities Development Command Chemical Biological Center (DEVCOM CBC), the synthesis of fentanyl was investigated via six synthetic routes, and the impurity profiles were compared to those of seized samples. The synthetic impurity phenethyl-4-ANPP was reliably observed in the Gupta-patent route published in 2013, and its structure was confirmed through isolation and structure elucidation. Organic impurity profiling results for illicit fentanyl samples seized in late 2021 have indicated yet another change in processing with the appearance of the impurity ethyl-4-anilino-N-phenethylpiperidine (ethyl-4-ANPP). Through altering reagents traditionally used in the Gupta-patent route, the formation of this impurity was determined to occur through a modification of the route as originally described in the Gupta patent.     

Characterization of an odor permeable membrane device for the storage of explosives and use as canine training aids

The storage and use of explosives is regulated at the state and federal level, with a particular focus on physical security and rigorous accounting of the explosive inventory. For those working with explosives for the training and testing of explosive-detecting canines, cross-contamination is an important concern. Hence, explosives intended for use with canine teams must be placed into secondary storage containers that are new, clean, and airtight. A variety of containers meet these requirements and include screw-top glass jars (e.g., mason jars). However, an additional need from the explosive-detecting canine community is secondary containers that can also be used as training aids whereby the volatiles emitted by explosives are emitted in a predictable and stable manner. Currently, a generally accepted method for the storage of explosives and controlled emission of explosive vapor for canine detection does not exist. Ideally, such containers should allow odor to escape from the training aid but block external contaminates such as particulates or other volatiles. One method in use places the explosive inside a permeable cotton bag when in use for training and then stores the cotton bag inside an impermeable nylon bag for long-term storage. This paper describes the testing of an odor permeable membrane device (OPMD) as a new way to store and deploy training aids. We measured the evaporation rate and flux of various liquid explosives and volatile compounds that have been identified in the headspace of actual explosives. OPMDs were used in addition to traditional storage containers to monitor the contamination and degradation of 14 explosives used as canine training aids. Explosives were stored individually using traditional storage bags or inside an OPMD at two locations, one of which actively used the training aids. Samples from each storage type at both locations were collected at 0, 3, 6, and 9 months and analyzed using Fourier Transform Infrared (FTIR) Spectroscopy and Gas Chromatography–Mass Spectrometry (GC–MS) with Solid-Phase Microextraction (SPME). FTIR analyses showed no signs of degradation. GC–MS identified cross-contamination from ethylene glycol dinitrate (EGDN) and/or 2,3-dimethyl-2,3-dinitrobutane (DMNB) across almost all samples regardless of storage condition. The contamination was found to be higher among training aids that were stored in traditional ways and that were in active use by canine teams.     

Evaluating the discriminating power of amino acid ratios on distinguishing dark colored hair samples

Human hairs are one of the most commonly encountered items of trace evidence. Currently, conventional methods for hair analysis include microscopic comparison and DNA analysis (nuclear and mitochondrial). Each approach has its own drawbacks. Hair proteins are stable and offer an alternative to DNA testing, as demonstrated with proteomics for distinguishing humans. However, proteomics is complicated and requires identifying peptides to remain intact following harsh sample preparation methods. Alternatively, the actual amino acid content of a hair sample may also offer important identifying information and actually requires proteins and peptides to be broken down completely rather than remaining intact. This study evaluated the discriminating power of using hair amino acid ratios to differentiate hair samples from 10 unrelated individuals with dark colored hair. Hair proteins were digested, derivatized, and analyzed using gas chromatography–mass spectrometry. Amino acid ratios were calculated for each individual and comparisons using ANOVA and post-hoc pairwise t-test with Bonferroni correction were made with amino acid ratios for individuals. Overall, out of the 45 possible pairwise comparisons between all hair samples, 38 (84%) were differentiable. Out of the 36 possible pairwise comparisons between brown haired individuals, 32 (89%) were considered differentiable using univariate statistics. Multivariate statistics were also attempted but, overall, univariate models were sufficient for exclusionary purposes. These results indicate that amino acid ratio analysis can potentially be used as an exclusionary method using hair if DNA analysis cannot be performed, or to corroborate conclusions made following microscopic analysis.     

Fatal Intoxication with Toluene Due to Inhalation of Glue

Two cases of fatal intoxications with toluene due to glue sniffing are described. In case 1, the autopsy did not indicate cause of death, while in case 2, the cause of death was determined to possibly be due to mechanical asphyxia by drowning. As the decedents had a history of glue sniffing, toxicological analyses were performed. Using gas chromatography with flame ionization detector and gas chromatography/mass spectrometry (GC/MS) with headspace method, toluene was detected in biological samples. Toluene ranged from 3.81 to 20.97 μg/g, with the highest concentrations observed in liver and brain (13.82–20.97 μg/g) in both cases. Based upon this data, the cause of death in both cases was determined to be toluene poisoning. Toxicological investigations are extremely important and should be considered mandatory in all deaths thought to be due to volatile substance abuse, as well as all deaths that are thought to be due to poisoning in young people.     

液化石油气中毒死亡兔的法医病理学研究

目的观察新西兰兔在液化石油气中毒后不同组织的病理学特征,探讨其在日常法医鉴定工作中的应用价值。方法健康新西兰兔42只,随机分为3组:轻度中毒组6只,中毒死亡组30只,窒息死亡组6只。在中毒和致死过程中进行行为学观察,分析心血中液化石油气浓度,中毒死亡组和窒息死亡组进行大体解剖形态学和组织病理切片观察及心血检验。结果轻度中毒组在吸入少量液化石油气后会表现为呼吸加快、站立、伸舌、磨牙等兴奋的状态;中毒死亡组尸体解剖主要表现皮肤、肌肉呈土黄色,气管、支气管出血明显,肺气肿明显;中毒死亡组心血中可检验出液化石油气成分。结论新西兰兔液化石油气中毒的特征主要表现为皮肤、肌肉呈土黄色,气管、支气管出血明显,心血可检出液化石油气成分。我们推断液化石油气的神经毒性与缺氧可能是液化石油气中毒死亡的机制。     

反相HPLC法同时测定大麻植物中的三种有效成分

目的建立同时测定大麻植物中四氢大麻酚(tetrahydrocannabinol,THC)、大麻二酚(cannabidiol,CBD)和大麻酚(cannabinol,CBN)三种有效成分的高效液相色谱(HPLC)法。方法采用通用C_(18)色谱柱,以乙腈-磷酸盐缓冲液(0.015 mol/L KH_2PO_4)为流动相,流速为1.0 m L/min,检测波长为220 nm,同时收集波长190~400nm的紫外光谱图,并以此光谱图及保留时间作为定性依据。结果所建方法能良好地分离THC、CBD和CBN,三种成分在0.4~40μg/m L范围内线性关系良好(R~2≥0.999 3),回收率大于87%,最低检出限分别为1.8、2.0和1.3 ng,日内精密度与日间精密度均小于5%。结论反相HPLC法简便、快速、准确,适用于大麻植物中THC、CBD和CBN的定性定量检测。