顶空单滴液相微萃取与气相色谱-质谱联用分析食品中挥发性的有机硒

Quantification of Volatile Organic Seleno Compounds in Food Samples by Headspace Single Drop Liquid Phase Microextraction Combined with Gas Chromatography-mass Spectrometry

建立了顶空单滴液相微萃取与气相色谱-质谱联用同时测定食品中挥发性有机硒的新方法。对影响顶空单滴液相微萃取萃取效率如萃取溶剂、萃取时间、萃取温度、搅拌速度及离子强度等进行了详细考察和优化。最佳的萃取条件：以正辛醇为萃取溶剂，样品在室温25℃，1000rpm的搅拌速度下，萃取5min。该方法对二甲基硒和二甲基二硒的检出限分别为0．26和0．22μg／kg，富集倍数为270和262倍；各物质的线性范围达3个数量级：相对标准偏差（RSDs，n=7）为8．7%-12．3％。将该方法应用于矿泉水、橙汁和大蒜中二甲基硒和二甲基二硒的分析，其加标回收的回收率为90．6％-97．8％。方法具有操作简单方便快速、灵敏度高、无交叉污染和环境友好等优点。

A method based on headspace single drop liquid phase microextraction combined with gas chromatography-mass spectrometry was developed for the determination of trace volatile organic seleno compounds in food stuff samples. Type of extraction solvent, extraction time, extraction temperature, stirring rate and ionic strength were investigated and optimized to obtain the best extraction efficiency for target analytes. Under the optimal conditions, the limits of detection （LODs, S/N=3） for the dimethylselenide and dimethyldiselenide were in the range of 0.22,4）.26 μg/kg with the enrichment factors （EFs） of 262-270 folds. To validate the proposed method, food samples collected from local supermarkets were analyzed and the recoveries of 90.6 %-97.8% were obtained. The method was found to be simple, fast, efficient and inexpensive.