本文建立胃内容物中乙蒜素的气相色谱-质谱联用（GC-MS）的分析检测方法,通过GC-MS分析确定乙蒜素的特征离子碎片和保留时间。取胃内容物2.0 g,匀浆化后,加入0.5 mL磷酸氢二钠-柠檬酸缓冲溶液（pH=3.0）,再加入二氯甲烷6.0 mL,高速（8 000 r/min）离心10 min,提取有机相。再加入6.0 mL二氯甲烷,涡旋振荡5 min重复提取一次,合并两次提取的有机相,氮气吹干后,加入0.1 mL乙醇定容,进行GC-MS (EI)分析。分析测试采用RTX-5MS弹性石英毛细管柱（30 m×0.25 mm×0.25 μm）,质谱采集模式为全扫描模式。结果显示,胃内容物中乙蒜素浓度在0.5~50 μg/g范围内,目标物检测峰面积与浓度呈良好线性关系（ R²=0.999 8）,最低检出限为0.5 μg/g,回收率在87.0%~89.9%之间,RSD≤4.5 ( n=5)。本方法简易快速、定性准确、回收率高、灵敏度高,能对胃内容物中的乙蒜素进行检测,填补了国内对乙蒜素进行GC-MS定性分析方法的空白,为侦查破案和案件定性提供技术支持。

A gas chromatography-mass spectrometry (GC-MS) analytical method was here established for determining both ethylicin in gastric contents and the rendered characteristic mass-spectral fragments from extracted compound at the specific retention time. Gastric contents (2.0 g) were homogenized and transferred into a 15 mL plastic tube where the additions were first done with 0.5 mL buffer solution (pH=3) of disodium hydrogen phosphate and citric acid then with 6 mL dichloromethane. The 15 mL plastic tube was shaken vigorously for 5 min and successively centrifμged at 8 000 r/min for 10 min, having the resultant organic phase tranferred into a new 15 mL plastic tube. The second extraction was repeated again with another 6.0 mL dichloromethane to have one more organic phase delivered from the gastric contents. The two-time obtained organic phases were combined together and transferred into another new 15 mL plastic tube, undergone with blowing to dry via a nitrogen stream. The dried sample was dissolved with ethanol (0.1 mL) and then analyzed by GC-MS under EI. Through optimal conditions of extraction and analysis, the analyte (ethylicin) was finally detected out from Rtx-5ms elastic quartz capillary column (30 m×0.25 mm×0.25 μm) under 140 °C at both the sampling inlet and transmission line, with the ion source temperature being at 200 °C plus the full scan (ranges among 45~200 amu) mode for ms collection. A good linear relationship was present between peak area and concentration of ethylicin in the range of 0.5~50 μg/g ( R²=0.999 8) spiked into the blank gastric content, demonstrating the related limit of detection (LOD) as 0.5 μg/g and the average recoveries among 87.0 %~89.9 %, RSD≤4.5 ( n=5). The method established here is simple, rapid, accurate, and high of sensitivity and recovery, capable of being used for determination of ethylicin in gastric contents, leaving it likely as the first attempt to conduct qualitative analysis of ethylicin by GC-MS in China. Therefore, the method should be able to provide technical support for relevant cases’ investigation and solving.