Separation and Detection of Smokeless Powder Additives by Ultra Performance Liquid Chromatography with Tandem Mass Spectrometry (UPLC/MS/MS),

A reversed phase gradient ultra performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS) method has been developed for the analysis of smokeless powders. A total of 20 different components were separated by UPLC and detected by MS/MS in multiple reaction monitoring (MRM) mode. These compounds included diphenylamines, centralites, nitrotoluenes, nitroglycerin, and various phthalates. Simultaneous positive and negative electrospray ionization (ESI) was used along with negative atmospheric pressure chemical ionization (APCI) to detect all compounds in a single analysis. Analysis times were under 8 min with a gradient of 10–73% organic at a flow rate of 0.500 mL/min. With this method, ultraviolet and MRM limits of detection ranging from 0.08 to 2.6 ng and 0.4–64 ng injected were achieved. Commercially available smokeless powders were also extracted with methylene chloride and characterized using the developed UPLC/MS/MS method. The procedure permits the determination of compositional differences between different brands as well as lot‐to‐lot variations.     

Α Simple Method for the Determination of Lacosamide in Blood by GC-MS

Lacosamide is a functionalized amino acid with antiepileptic function. Therapeutic drug monitoring (TDM) in patients for lacosamide is critical as it allows clinicians to control epileptic seizures. A single liquid–liquid extraction step was applied for the extraction of lacosamide from whole blood samples which were thereafter analyzed by GC-MS. Optimum extraction conditions were selected on the basis of experiments with various solvents at different pHs, indicating ethyl acetate at pH 12 as the most efficient parameters for the extraction of lacosamide. Method exhibited linearity from 2 to 100 μg/mL with R² = 0.998. Accuracy and precision were evaluated at three concentrations and found to be within acceptable limits. LOD and LOQ were determined at 0.1 and 0.5 μg/mL, respectively. Lacosamide was found to be stable at storage conditions. The developed method was applied successfully in clinical samples and postmortem blood sample from an overdose case.     

A fatal case of suspected anaphylaxis with cefoperazone and sulbactam: LC-MS analysis

Cefoperazone and sulbactam are prescribed in combination and used in the treatment of moderate to severe bacterial infections. Serious anaphylaxis is a rare side effect. This report describes a fatal case of suspected anaphylaxis after intravenous administration of a combination of the two drugs. Heart blood was analyzed for cefoperazone by protein precipitation with acetonitrile and by liquid-liquid precipitation for sulbactam after protein precipitation with aqueous acetonitrile, followed by tandem mass spectrometry in the product ion scan mode for identification and by liquid chromatography mass spectrometry in the selected ion monitoring mode for quantitation. Calibration curves for cefoperazone and sulbactam were linear over the range 0.07 to 1.93 and 0.046 to 0.914 microg/ml respectively. The decedent's blood concentrations of cefoperazone and sulbactam were 0.368 and 0.143 microg/ml respectively. As these concentrations were below concentrations reported after single dosing studies and below those considered to be minimally inhibitory, death was presumed to have been caused by hypersensitivity and not an overdose. In conclusion, this procedure is useful for detecting and quantitating cefoperazone and sulbactam in postmortem blood and may be useful in the evaluation of anaphylaxis.     

Blood versus bone marrow pentobarbital concentrations

Postmortem pentobarbital levels in rabbit heart blood and bone marrow were determined and compared. The average ratio of femur marrow/blood pentobarbital concentrations in 24 rabbits was 1.06 +/- 0.05. The average percent difference between actual plasma pentobarbital concentrations and calculated plasma pentobarbital concentrations was 5.82 +/- 1.96. Concentrations were determined by gas chromatography of extracted, derivatized pentobarbital.     

液氯运输泄漏的应急救援行动预案实例

本文以液氯运输过程中发生泄漏这一典型事故为例，针对液氯的物理化学特性，制定专项的应急救援行动预案，详细阐述了应急的程序、战术对策、行动准则和伤员救治方法，为液氟等化学危险品的现场应急行动提供了指南。     

HPLC测定豨莶片剂中奇壬醇的含量

目的:建立豨莶片剂中奇壬醇的含量测定方法.方法:采用HPLC,色谱条件为:Phenomenex C18柱,乙腈-0.05 mol/L KH2PO4(125∶75)为流动相,流速1.0 ml/min,检测波长215 nm.结果:奇壬醇在0.133～2.660 μg范围内呈良好的线性关系(r=0.999 9),平均回收率为99.4%,RSD=2.12%;测定3批豨莶片剂中奇壬醇的含量分别为109.46,105.91,107.41 μg/片.结论:HPLC简便、准确、可控,可作为豨莶片剂的定量检测方法.     

应用低离子强度溶液提高血痕MN血型测定的灵敏度

应用低离子强度溶液能提高凝集试验的灵敏度。本实验采用低离子强度溶液及蛋清薄膜固定解离法对保存1～6年的258份血痕进行MN血型盲测。结果总正确率94.57％。证明应用低离子强度溶液解离法的灵敏度明显优于盐水解离法。     

大鼠死后不同组织电导率与死亡时间关系的研究

目的测定不同死亡时间大鼠脑、肺、肝和骨骼肌电导率,研究不同组织器官EC与PMI的关系。方法 SD大鼠处死后,保存于25℃恒温条件下,于死后即刻(0d)、1d、2d、3d、4d、5d、6d和7d提取大鼠脑、肺、肝和骨骼肌,四种组织器官与去离子水按照一定比例制成浸渍液,测定各组织器官浸渍液EC值;分析其EC值与PMI的关系,建立与PMI关系的回归方程;比较大鼠死后四种组织器官EC变化规律,探讨不同组织器官腐败进程。结果死后1d内骨骼肌与脑组织EC无显著变化,2~7d快速增加;而肝、肺EC值在1d内已开始增加,且2~7d内均快速上涨。四种组织器官EC与PMI的关系用三次方程拟合较好,其中肝的相关系数最高,R~2=0.96,且四种组织器官的EC值在不同的PMI区段之间呈现出不同的增长规律。结论大鼠脑、肺、肝和骨骼肌EC与PMI相关性均较好,测定尸体组织器官EC有望成为法医实践中PMI推断的有效方法。     

Characterization and Differentiation of Geometric Isomers of 3‐methylfentanyl Analogs by Gas Chromatography/Mass Spectrometry,Liquid Chromatography/Mass Spectrometry,and Nuclear Magnetic Resonance Spectroscopy

The cis and trans isomers of 3‐methylfentanyl and its three analogs were chemically synthesized, and these compounds were characterized and differentiated by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), and nuclear magnetic resonance (NMR) spectroscopy. The cis and trans isomers of the 3‐methylfentanyl analogs were completely separated by GC/MS. Although the high temperature of the GC injection port caused thermal degradation of β‐hydroxy‐3‐methylfentanyl, the degradation was completely suppressed by trimethylsilyl derivatization. The isomers were also well separated by LC/MS on an octadecylsilyl column with 10 mM ammonium acetate and methanol as the mobile phase. The proton NMR signals were split when the hydrochloride salts of the 3‐methylfentanyl analogs were dissolved in deuterated chloroform because stereoisomers were formed by the coordination of the hydrochloride proton to the nitrogen of the piperidine ring of the 3‐methylfentanyl analogs.     

Photo‐ and Thermal‐Degradation Studies of Select Eccrine Fingerprint Constituents

Abstract: Photo‐ and thermal‐degradation studies on eccrine fingerprint components are presented herein. Dilute distinct solutions of urea, lactic acid, and seven amino acids were deposited on steel coupons and Teflon^® disks, exposed to artificial sunlight or heat, extracted, and analyzed. This aim of this study was to determine whether the investigated eccrine components, previously determined to be Raman active for a parallel study, experienced photo‐ or thermally induced degradation, and if so, to determine the rate and identify any detectable products. Neither the amino acids nor urea exhibited photo‐degradation; however, when heated for a period of three minutes, the onset of thermal‐degradation was initiated at 100°C for the amino acids and 100°C for urea. Lactic acid, the major polymerization initiator of superglue fuming, showed photochemical and thermal‐degradation. These results could be used for future development of new latent fingerprint visualization methods, especially when lactic acid is degraded.