土壤中痕量水胺硫磷的微波辅助萃取-固相微萃取-GC-MS法测定

Determination of Isocarbophos in Soil Sample by Gas Chromatography-Mass Spectrometry with Combination of Microwave-assisted Extraction and Solid Phase Microextraction

研究了微波辅助萃取 (MAE) -固相微萃取 (SPME)联合萃取、气相色谱 -质谱法 (GC -MS)测定土壤中水胺硫磷的分析方法 ;采用正交设计试验优化了微波升温程序、萃取温度、萃取时间、萃取溶剂体积等MAE条件 ;研究了SPME萃取涂层、萃取时间、解吸温度等对萃取效率的影响 ;方法的线性范围在1.0～20μg/L之间 ,检出限为0.49ng/g;测定25、100ng/g加标土壤样品 ,回收率分别为79 %和107 % ,RSD分别为2.6%和6.5 % ;方法综合了MAE快速高效和SPME富集浓缩的优点 ,以水为萃取溶剂。

A method for the determination of isocarbophos in soil sample was developed by gas chromatography-mass spectrometry with combination of microwave _ assisted extraction(MAE)and solid phase microextraction(SPME).The conditions of MAE including water volume,time of raised temperature,extraction temperature and holding time were optimized by an orthogonal layout design of4factors at3levels.Factors affecting the efficiency of SPME such as type of extraction coating,extraction time,desorption temperature and time were evaluated.The linearity of the method was good over the range of1.0to20μg/L for isocarbophos with the detection limit of0.49ng/g.Two soil samples with spiked concentration of isocarbophos at levels of25ng/g and100ng/g were deterˉmined with recoveries of79%and107%,the RSDs were2.6%and6.5%(n=6),respectively.The method combines the advantages of high speed and efficiency for MAE and enrichment of sample for SPME.It is organoˉsolvent_free,and suitable for the determination of trace organic compounds in soil sample.