A gas chromatography–electron ionization–tandem mass spectrometric (GC–EI–MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl‐4‐carboxylic acid (ZPCA) and zolpidem 6‐carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC–EI–MS/MS. The linear ranges were 8–100 pg/mg for ZPCA and 16–200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra‐ and inter‐day precisions were within 16.9 and 11.7%, while intra‐ and inter‐day accuracies were −7.0–8.7 and −2.8–7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9–35.9 pg/mg and ZCA 16.6–21.8 pg/mg. The method proved to be suitable for picogram‐level determination of ZPCA and ZCA in human hair.

中文翻译：

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气相色谱-电子电离-串联质谱法测定头发中的唑吡坦苯基-4-羧酸和唑吡坦6-羧酸

气相色谱-电子电离-串联质谱（GC-EI-MS / MS）的方法已经开发并验证用于测定唑吡坦，唑吡坦苯基-4-羧酸（ZPCA）和唑吡坦6-羧酸的主要代谢物（ ZCA）。样品制备程序涉及去污，机械粉碎，孵育，提取和纯化，然后进行仪器分析。提取物使用六氟异丙醇和七氟丁酸酐衍生化，并通过GC-EI-MS / MS进行分析。ZPCA的线性范围为8–100 pg / mg，ZCA的线性范围为16–200 pg / mg，相关系数> 0.997。ZPCA的检出限为1.8 pg / mg，ZCA的检出限为1.7 pg / mg。回收率在77.6至111.7％之间。日内和日间精度在16.9和11.7％之间，而日内和日间准确度分别为-7.0-8.7％和-2.8-7.8％。所开发的方法用于分析从怀疑的唑吡坦滥用者获得的法医头发样品，并监测了以下浓度范围：ZPCA 11.9–35.9 pg / mg和ZCA 16.6–21.8 pg / mg。实践证明该方法适用于皮毛级人发中ZPCA和ZCA的测定。