气相色谱法测定尿液中可卡因及其代谢物爱冈宁甲基酯

建立了尿样中可卡因（COC）及其代谢物爱冈宁甲基酯（EME）的气相色谱检测方法。 采用液液萃取法提取尿样中可卡因和爱冈宁甲基酯，考察了萃取剂种类和用量、试样pH值以及萃取时间等因素对提取效果的影响。 结果表明，尿样中COC和EME的最佳液液萃取条件是：以V(氯仿)∶V(异丙醇)=9∶1为提取溶剂，调节样品溶液pH=9.5，在40 ℃ 水浴振荡提取6 min。 COC和EME日内精密度分别为1.73%和1.44%，日间精密度分别为2.57%和2.89%，最低检出限（LOD）为0.040 mg/L。 此法无需衍生化、快速、准确、灵敏度高，可同时检测尿样中COC和EME的含量。

Determination of Cocaine and Its Metabolite Ecgonine Methyl Ester in Human Urine by Gas Chromatography

A facile method has been set up for the determination of cocaine(COC) and its metabolite ecgonine methyl ester(EME) in human urine by means of gas chromatography(GC) with a flame ionization detector(FID). The urine samples were prepared by liquid-liquid extraction(LLE). To improve the extraction efficiency, the experimental parameters of LLE, including extraction solvent and its amount, pH value of the urine sample and extraction time were investigated. The optimized conditions are:8.0 mL of chloroform-isopropanol(volume ratio 9∶1), was used extractant, the pH value of urine sample is around 9.5, the extraction temperature and time are 40 ℃ and 6 min, respectively. The intra-day precisions of COC and EME were 1.73% and 1.44% while the inter-day precisions of COC and EME were 2.57% and 2.89%, respectively. The limits of detection(LOD) for both were 0.04 mg/L. The derivatization of COC and EME in traditional detection process could be bypassed in this protocol. The results indicate that the developed method is rapid, accurate and sensitive, which can be used for the simultaneous determinations of COC and EME in urine samples for forensic applications.