UPLC-MS/MS法检测血痕中常见烟草、毒品和药物成分

目的建立UPLC-MS/MS测定血痕中尼古丁、可替宁、甲基苯丙胺、氯胺酮、吗啡、O6-单乙酰吗啡、地西泮、三唑仑、艾司唑仑、佐匹克隆和利血平的方法。方法以甲醇为提取液,采用基质提取溶液配制标准溶液制作定量曲线。采用超高效液相色谱柱对待测样品进行分离;以电喷雾离子源正离子（ESI＋）模式和多反应监测（MRM）模式进行质谱分析。优化实验条件,并进行方法学评价。结果选择UPLC HSS T3色谱柱,乙腈-5mmol/L甲酸铵＋0.1%（v/v）甲酸作为流动相,甲醇作为提取溶剂。11种检测物检出限（S/N=3）和定量限（S/N=10）分别为0.04~2.82ng和0.13~7.64ng,1~500ng/mL范围内的线性关系良好。除利血平、吗啡外的检测物回收率为（53.8±5.3）%~（107.2±12.6）%。结论采用本文UPLC-MS/MS方法对血痕中11种常见烟草、毒品和药物成分进行检测,能够满足实际检案的要求,可在相关检验中选用。     

用dHPLC技术检测线粒体DNA编码区单核苷酸多态性

目的研究线粒体DNA(m tDNA)编码区单核苷酸多态性,建立检测m tDNA编码区单核苷酸多态性(SNP)的变性高效液相色谱(dHPLC)方法。方法设计针对线粒体DNA编码区nt10287-10679及nt8507-8805引物,应用dHPLC技术检测其序列多态性。结果100例中国汉族无关个体中,m tDNA nt10287-10679检出13个SNP位点,13种单倍型,基因多样性(H)为70.79%,偶合概率(P)为29.92%;m tDNA nt8507-8805检出10个SNP位点,12种单倍型,H为70.42%,P为30.28%;两段序列联合起来共检出23个SNP位点,23种单倍型,H为84.14%,P为16.70%。结论所建立的dHPLC方法可用于快速、准确地检测m tDNA编码区序列多态性;m tDNA编码区多态性位点作为m tDNA控制区多态性位点的补充,联合应用可以提高m tDNA的个体识别能力。     

Detection of Cutting Agents in Drug‐Positive Seized Exhibits within the United States

The following report summarizes a study performed on seized drug exhibits collected in two U.S. states to evaluate the presence and identification of cutting agents. Aliquots of seized drug materials from Kentucky (n = 200) and Vermont (n = 315) were prepared using a dilute‐and‐shoot procedure. Initial analysis was performed using gas chromatography–mass spectrometry (GC‐MS) followed by analysis using liquid chromatography quadrupole time‐of‐flight mass spectrometry (LC‐QTOF). Active compounds detected overall included caffeine (31.0%), quinine/quinidine (24.7%), levamisole (11.6%), acetaminophen, (8.2%) and procaine (8.2%). These compounds were found with several drugs of abuse, such as heroin, fentanyl, methamphetamine, and cocaine. This novel information about cutting agents used to dilute or alter drugs of abuse is important to criminal investigations and in the management of acute intoxications at health centers. However, common methodologies for analysis and standard reporting practices frequently do not include cutting agents, resulting in lacking or inadequate information regarding prevalence of these substances.     

液相色谱-三重四极杆质谱法同时检测生物检材中百草枯及其代谢物

目的建立生物检材中同时检测百草枯(paraquat,PQ)及其主要代谢物单季铵盐(monoquat)、百草枯-单吡啶酮(paraquat-monopyridone,MP)、百草枯-联吡啶酮(paraquat-dipyridone,DP)、4-羧基-1-甲基吡啶盐(4-Carboxy-1-methylpyridinium ion,MINA)的液相色谱-串联质谱(LC-MS/MS)检测方法。方法以百草枯氘代内标(Paraquat-d8 Dichloride,PQ-D8)作为内标,检材样品调节pH后,经乙腈沉淀蛋白,使用不同色谱柱洗脱,在多反应监测模式下检测。结果百草枯PQ、monoquat、MP、DP、MINA的线性范围分别是5~800ng/mL、0.5~80ng/mL、5~800ng/mL、2.5~400ng/mL、2~320ng/mL(r均高于0.993),日内、日间精密度(RSDs)分别在5%~14%、3%~13%、3%~15%、5%~13%、2%~15%之间,准确度(RE)分别在91%~116%、80%~100%、80%~111%、85%~114%、91%~114%之间。生物样品处理后自动进样器上室温放置72h,各物质的准确度分别在90%~119%、56%~125%、60%~110%、78%~98%、83%~117%之间。结论本测定方法前处理过程简便,分离效果好,提取效率高,可使用本方法对疑似百草枯中毒的检材进行原体及代谢物的检测,为案件提供法律依据;本实验优化了课题组前期建立的生物样品中百草枯及monoquat、MP的检测方法,参考其案例结果,检测相应检材,对比分析,该检测方法在原体含量大幅下降时,痕量代谢物仍可检出。     

Availability of target odor compounds from seized ecstasy tablets for canine detection

The aim of this study was to compare seized samples of 3,4-methylenedioxy-N-methylamphetamine (MDMA) pills, used to train law enforcement detection canine teams, to determine what differences exist in the chemical makeup and headspace odor and their effect on detectability. MDMA solutions were analyzed by liquid chromatography-mass spectrometry. Analysis of these samples showed a wide variance of MDMA (8-25%). Headspace SPME-GC/MS analysis showed that several compounds such as 3,4-methylenedioxyphenylacetone and 1-(3,4-methylenedioxyphenyl)-2-propanol are common among these MDMA samples regardless of starting compound and synthesis procedure. However, differences, such as the level of the various methylenedioxy starting compounds, were shown to affect the overall outcome of canine detection, indicating the need for more than one MDMA training aid. Combinations of compounds such as the primary odor piperonal in conjunction with a secondary compound such as MDP-2-OH or isosafrole are recommended to maximize detection of different illicit MDMA samples.     

Development and validation of a simple GC-MS method for the simultaneous determination of 11 anticholinesterase pesticides in blood--clinical and forensic toxicology applications

Anticholinesterase pesticides are widely used, and as a result they are involved in numerous acute and even fatal poisonings. The aim of this study was the development, optimization, and validation of a simple, rapid, specific, and sensitive gas chromatography-mass spectrometry method for the determination of 11 anticholinesterase pesticides (aldicarb, azinphos methyl, carbofuran, chlorpyrifos, dialifos, diazinon, malathion, methamidophos, methidathion, methomyl, and terbufos) in blood. Only 500 μL of blood was used, and the recoveries after liquid-liquid extraction (toluene/chloroform, 4:1, v/v) were more than 65.6%. The calibration curves were linear (R(2) ≥ 0.996). Limit of detections and limit of quantifications were found to be between 1.00-10.0 and 3.00-30.0 μg/L, respectively. Accuracy expressed as the %E(r) was found to be between -11.0 and 7.8%. Precision expressed as the percent relative standard deviation was found to be <9.4%. The developed method can be applied for the investigation of both forensic and clinical cases of accidental or suicidal poisoning with these pesticides.     

The Characterization of 3,4-Dimethylmethcathinone (3,4-DMMC)

Analogs and derivatives of traditional illicit drugs are ever increasing in variety and creativity. Staying abreast of the new developments is a constant challenge for every forensic laboratory. Recently, a seizure from Australian Customs Service presented our laboratory with the designer cathinone 3,4-dimethylmethcathinone (3,4-DMMC). Gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy, and ultraviolet (UV) spectrophotometry were employed to analyze the spectroscopic characteristics of this cathinone. As an analog, 3,4-DMMC exhibits similar if not identical IR and UV profiles to mephedrone (4-MMC) and methcathinone; however, the retention time from GC is unique as expected, and the electron impact fragmentation pattern is consistent with the fragmentation pattern of other cathinones. The chemical shifts of the carbons and hydrogens were assigned by both one- and two-dimensional NMR techniques, while the molecular weight was confirmed by LC/MS.     

高效液相色谱法鉴别染料型黑色喷墨打印字迹

目的建立液相色谱分析方法,对市售的30种不同厂家牌号（原装）染料型黑色喷墨打印字迹进行区分鉴别。方法通过选择最佳的提取条件、流动相,考察纸张、字迹形成方式等的影响,及样品及仪器的稳定性实验,确定实验条件。结果选择了最佳的反相高效液相色谱（RP-HPLC）分析方法：固定相为X-bridge Shield RP18（3.5μm,4.6×100mm）,流动相为乙腈-NH4HCO3溶液（10mmol/L）,梯度洗脱,检测波长为585nm、475nm;用该方法,根据字迹染料成分的差异将30种样品分为四大类17小类。结论该方法可以为鉴别区分不同厂家染料型黑色喷墨打印字迹提供依据。     

液相色谱-串联质谱法分析生物检材中的河豚毒素

目的建立血液、尿液以及肝中河豚毒素(tetrodotoxin,TTX)的液相色谱-串联质谱分析方法,并进行方法学验证。方法血液、尿液和肝用1%乙酸甲醇溶液去蛋白后,上清液用固相萃取法净化,LC-MS/MS检测。结果血液、尿液和肝中TTX检出限分别为2ng/mL、2ng/mL和4ng/g。血液和尿液在4～100ng/mL、肝在5～100ng/g的范围内线性关系良好,相关系数r≥0.9973;日内精密度和日间精密度均在12.80%以内;回收率大于47.2%。结论所建方法高效、灵敏、准确,可以为河豚毒素中毒的法医学鉴定、临床诊治以及食品安全的监控提供技术保障。     

Analysis of Gunshot Residue and Associated Materials—A Review

Abstract: A comprehensive review of the scientific literature on gunshot residue (GSR) is presented. Aspects of both inorganic and organic GSR are discussed, from formation and distribution, to sample collection, preparation, and analysis using a variety of techniques. The interpretation of GSR results is also considered including issues surrounding the contamination, distribution, and transfer of GSR. Potential problems with ulterior sources of GSR like particles have been reported in the literature. For example, particles from environmental and occupational sources have been highlighted as exhibiting similar chemical and morphological characteristics to GSR. These findings are put into context with regard to interpreting samples. A move toward a “case by case” approach is argued to be more preferable to a “formal” classification system where possible. The analysis of both inorganic and organic compositions of residue samples as well as morphological considerations is considered to be a more ideal approach to GSR analysis, whereever practicable.