动态液相微萃取-微波衍生化-气相色谱/选择离子检测-质谱法测定毛发中的苯丙胺类毒品

建立了一种便捷的毛发中4种苯丙胺毒品的检测方法。采用动态液相微萃取法用氯仿提取毛发消解液中的苯丙胺类毒品，然后在微波加热的条件下用N-甲基-双三氟乙酰胺(MBTFA)进行衍生化处理，将反应液直接用气相色谱/选择离子检测-质谱法（GC/SIM-MS）检测。以2-甲基苯乙胺为内标，在空白毛发中添加标准品做标准曲线得到4种苯丙胺类毒品的线性相关系数均不小于0.996。衍生化后4种毒品在毛发中的最小检测限(S/N=3)均为50 pg/mg。4种苯丙胺类毒品在毛发中的添加浓度为5 ng/mg时,5次测定的相对标准偏差（RSD）分别为苯丙胺6.0%,甲基苯丙胺13.9%,3，4-(亚甲二氧基)苯丙胺10.2%,3，4(亚甲二氧基)-甲基苯丙胺9.2%。应用所建立的方法对苯丙胺类毒品吸食者的毛发进行检测,检出了这4种毒品,毛发样品的最小用量为4.6 mg (约20 cm 长)。该方法灵敏、简便、快速,可用于毛发中低含量苯丙胺类毒品的分析。

Determination of Amphetamines in Human Hair Using Dynamic Liquid-Phase Microextraction and Gas Chromatography/Selected Ion Monitoring-Mass Spectrometry After Microwave erivatization

Human hair is an important specimen for drug abuse analysis owing to its easy collection, long surveillance time window and good correlation between the "degree of addiction" and actual drug concentration. A simple method for determination of 4 amphetamines in human hair was developed. The hair was digested under basic condition, and the drugs in it were extracted using microvolume of chloroform. The organic layer was then transferred into another tube to be derivatized with N-methyl-bis (trifluoroacetamide) (MBTFA) by microwave heating. Finally the reacted solution was detected by gas chromatography/selected ion monitoring-mass spectrometry (GC/SIM-MS) directly. 2-Methyl-phenyl ethylamine was used as an internal standard. Good linearities were obtained for 4 amphetamines with correlation coefficients better than 0.996. The limits of detection, based on a signal-to-noise ratio (S/N) of 3:1, were all about 50 pg/mg for amphetamine (AM) , methamphetamine (MAM), methylenedioxy-amphetamine (MDA), and methylenedioxy-methamphetamine (MDMA) in hair. The reproducibility of the method was satisfactory, with the relative standard deviations of 6.0% for AM, 13.9% for MAM, 10.2% for MDA and 9.2% for MDMA. Some real hair from the drug abusers was analyzed with this method. The minimal hair is less than 5 mg (about 20 cm). The method is highly sensitive, easy to operate, time-saving and economic, which can be used for trace analysis of amphetamines in human hair.