Evaluation of Internal Standards for the Analysis of Ignitable Liquids in Fire Debris

Abstract:  An evaluation of eight compounds for use as an internal standard in fire debris analysis was conducted. Tests were conducted on tetrachloroethylene, chlorobenzene, n-octylbenzene, 3-phenyltolune, and deuterated compounds toluene-d8, styrene-d8, naphthalene-d8, and diphenyl-d10 to measure the extraction efficiency of each compound in the presence of an interfering volatile compound (carbon disulfide). Other tests were conducted to evaluate whether or not the presence of an ignitable liquid or pyrolysis/combustion products from fire debris would interfere with the identification of these compounds when used as an internal standard. The results showed that while any of the eight compounds could be used as an internal standard in fire debris analysis, the more volatile compounds (toluene-d8, tetrachloroethylene, chlorobenzene, and styrene-d8) showed better extraction efficiencies at room temperature than when heated to 60°C. Each of the less volatile compounds (naphthalene-d8, diphenyl-d10, n-octylbenzene, and 3-phenyltolune) performed well during extraction at 60°C, while naphthalene-d8 showed better extraction efficiency in the presence of competing volatiles when extracted at room temperature.     

Detection of Acute Diazepam Exposure in Bone and Marrow: Influence of Tissue Type and the Dose‐Death Interval on Sensitivity of Detection by ELISA with Liquid Chromatography Tandem Mass Spectrometry Confirmation*

Abstract: Enzyme‐linked immunosorbent assay (ELISA) and liquid chromatography tandem mass spectrometry (LC/MS/MS) were used to detect diazepam exposure in skeletal tissues of rats (n = 15) given diazepam acutely (20 mg/kg, i.p.), and killed at various times postdose. Marrow, epiphyseal, and diaphyseal bone were isolated from extracted femora. Bone was cleaned, ground, and incubated in methanol. Marrow underwent ultrasonic homogenization. Extracts and homogenates were diluted in phosphate buffer, and then underwent solid‐phase extraction and ELISA. Relative sensitivity of detection was examined in terms of relative decrease in absorbance (ELISA) and binary classification sensitivity (ELISA and LC/MS/MS). Overall, the data showed differences in relative sensitivity of detection of diazepam exposure in different tissue types (marrow > epiphyseal bone > diaphyseal bone), which is suggestive of heterogenous distribution in these tissues, and a decreasing sensitivity with increasing dose‐death interval. Thus, the tissue type sampled and dose‐death interval may contribute to the probability of detection of diazepam exposure in skeletal tissues.     

Thiodicarb and methomyl tissue distribution in a fatal multiple compounds poisoning

Abstract:  Thiodicarb is a nonsystemic carbamate insecticide whose acetylcholinesterase activity is related to its main methomyl degradation product. A 40-year-old woman was found dead in her car. Empty packages of medicines and an open bottle of Larvin^® containing thiodicarb were found near her body. No signs of violence nor traumatic injuries were noticed upon autopsy, and police investigations strongly suggested a suicide. Systematic toxicological analysis performed on postmortem specimens revealed the presence of various sedatives, hypnotics, and antipsychotic drugs in blood, urine, and gastric content. Some of the compounds identified were determined at blood concentrations well above the known therapeutic concentrations: zolpidem (2.87 mg/L), bromazepam (2.39 mg/L), nordazepam (4.21 mg/L), and levopremazine (0.64 mg/L). Specific analysis of thiodicarb and of its methomyl metabolite was then performed on all fluids and tissues collected during autopsy by liquid chromatography ion trap tandem mass spectrometry (LC-MS-MS). The anticholinesterase capacity of blood, urine, and gastric content collected at autopsy was 83%, 82%, and 32%, respectively (normal value: 0%). The presence of thiodicarb in the bottle found near the body corroborates the hypothesis of an intake of that compound. Although thiodicarb was only detected in gastric content (24.3 mg/L), its methomyl metabolite was quantified in most postmortem tissues and fluids: gastric content (19.9 mg/L), peripheral blood (0.7 mg/L), urine (8.5 mg/L), bile (2.7 mg/L), liver (0.7 mg/kg), kidney (1.7 mg/kg), lung (1.5 mg/kg), brain (9.3 mg/kg), and heart (3.6 mg/kg).     

Morbidity Involving the Hallucinogenic Designer Amines MDA and 2C‐I*

Abstract: A case is presented of a 39‐year‐old woman who suffered severe debilitation because of a hemorrhagic stroke in the context of substance abuse. The patient presented to the emergency room with rapidly diminishing mental status, hypertension, and vasoconstriction; her friends provided a history of ingestion of cocaine, 3,4‐methylenedioxymethamphetamine (MDMA), and 2C‐I, a novel designer amine. A multi‐targeted LC‐MS/MS method for sympathomimetic amines and related drugs in urine detected and quantified 2C‐I and MDA, while ruling out MDMA. The cause of the stroke was determined to be an underlying cerebrovascular abnormality called Moyamoya, secondary to substance abuse. In clinical laboratories, gas chromatography–mass spectrometry or liquid chromatography–tandem mass spectrometry (LC‐MS/MS) confirmation of a positive amphetamine immunoassay is usually directed only towards amphetamine, methamphetamine, MDMA and MDA. This report demonstrates the utility of testing for a wider menu of compounds using LC‐MS/MS in order to better characterize the prevalence and toxicities of novel amines such as 2C‐I.     

LC-MS/MS同时测定人血浆中氯氮平、奥氮平和米氮平

目的 建立人血浆中氯氮平、奥氮平、米氮平的液相色谱-串联质谱(LC-MS/MS)检测方法.方法 血浆中的氯氮平、奥氮平、米氮平用乙醚液-液萃取,采用Agilent Zorbax SB-C18柱(2.1mm×l50mm,5 μm),电喷雾离子源,正离子检测,多反应监测方式进行定量分析,卡马西平作为内标.结果 氯氮平、奥氮平和米氮平的检测限为0.41～0.92ng/mL,质量浓度在10.0～2000.0ng/mL范围内线性良好(r≥0.9924),平均萃取回收率在65.7%～94.2%,日内、日间精密度RSD≤6%(n=5).结论 该方法专属性强、灵敏及准确,可以适用于法庭与临床毒物分析.     

HPLC法测定百草枯急性中毒大鼠的体内分布

目的 应用高效液相色谱法对口服百草枯急性中毒大鼠体内分布进行测定。方法以200mg／kg剂量百草枯给予Wister大鼠灌胃,4h后脱臼处死,解剖取脑、心、肝、脾、肺、肾、胃、盲肠、肌肉等组织,应用固相萃取法提取,液相色谱法测定各器官组织中百草枯含量。结果各组织经检验,均检出百草枯;组织间百草枯含量（μg／g）相差明显,其中最高为胃（231．47±129．10）,其次为盲肠（87．08±39．86）、肺（22．73±10．20）,最低为心（2．01±0．36）。结论百草枯口服给药后组织分布较为广泛,除胃、肠外各脏器中以肺浓度最高。     

苯二氮卓类新精神活性物质去氯依替唑仑的定性检验方法研究

目的建立苯二氮卓类新精神活性物质去氯依替唑仑的气相色谱-质谱(GC-MS)和超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)定性检验方法。方法未知样品用甲醇和水提取,取上清液,采用GC-MS和UPLC-Q-TOF MS进行分析。结果经GC-MS检测,保留时间为17.73 min的未知组分的质谱碎片主要特征离子峰有m/z 279,308,239,252,225,77,126。经UPLC-Q-TOF MS检测,保留时间为4.781 min的未知组分的准分子离子峰为309.1173,碰撞诱导解离(CID)模式下二级质谱主要离子有m/z 280.0776,255.0952,240.0719,225.0604,206.0748。经缴获毒品分析科学工作组(Scientific Working Group for the Analysis of Seized Drugs,SWGDRUG)分析谱库检索和文献查询获得的信息资料进行比对,鉴定为去氯依替唑仑。结论该方法具有分析简便、快速的特点,可以用于实际案件的检测。     

离子液体分散液相微萃取-HPLC检测血浆中溴敌隆

目的建立离子液体分散液相微萃取-HPLC检测血浆中溴敌隆的方法。方法以1-己基-3-甲基咪唑六氟磷酸盐([HMIM]PF6)为萃取剂,甲醇为分散剂,提取血浆中的溴敌隆,用HPLC分析其含量;考察了萃取剂和分散剂体积、样品pH值、NaCl浓度、萃取时间和离心时间等因素对萃取效率的影响。结果优化的溴敌隆分散液相微萃取操作条件为:萃取剂[HMIM]PF650μL,分散剂甲醇100μL,样品pH值5.0,萃取时间5min,离心时间8 min。方法的线性范围:0.01～5.0μg/mL,检测限:1.1 ng/mL(S/N3)。该法低、中、高浓度的平均加标回收率分别为76.4%,82.6%,92.1%,RSD分别为4.17%,2.99%,1.67%(n=6)。结论本方法检测血浆中的溴敌隆,简便快速、准确实用,满足中毒检测及临床诊断治疗的需要。     

凤丹皮总苷高效液相色谱特征指纹图谱研究

目的 建立凤丹皮总苷的指纹图谱,为科学评价及有效控制其质量提供可靠依据。方法 采用Agilent TC-C18(2)（250 mm×4.6 mm,5 μm）色谱柱;乙腈（A）-0.05%磷酸水（B）为流动相,梯度洗脱,流速1.0 mL/min,检测波长230 nm,进样容积20 μL。结果 建立了凤丹皮总苷高效液相色谱特征指纹图谱的共有模式,指定18个共有峰,统计结果显示,11批凤丹皮总苷样品高效液相色谱特征指纹图谱相似度均大于0.80。结论 建立的特征指纹图谱方法快速、准确、简便,可用于凤丹皮总苷的质量控制。     

反向高效液相色谱法测定覆盆子中3种三萜酸的含量

目的 采用反相高效液相色谱法建立覆盆子中三萜类成分（山楂酸、科罗索酸和齐墩果酸）的测定方法,为中药覆盆子的质量评价提供依据。方法 色谱柱：WondaSil C18-WR（250 mm×4.6 mm,5 μm）,流动相为乙腈（A）-0.2%磷酸水溶液（B）（9∶1）,等度洗脱,柱温为25 ℃,流速0.6 mL/min,检测波长205 nm,进样量10 μL。结果 山楂酸、科罗索酸、齐墩果酸分别在0.156～3.900 μg、0.102～2.55 μg、2.04～51 μg范围内与峰面积呈现良好的线性关系。平均加样回收率分别为95.0%、91.7%、93.8%,RSD分别为2.59%、3.25%、2.86%。结论 该方法简单、可行,可作为覆盆子药材中单一三萜类成分含量的测定方法。