称取5 g预处理好的土壤样品至索氏提取器中,以二氯甲烷为提取溶剂进行提取。提取液经HLB固相萃取小柱净化,甲醇洗脱,收集所有洗脱液,氮吹至近干,最后用甲醇定容至1 mL,于气相色谱-三重四极杆串联质谱仪中以多反应监测模式进行分析,外标法定量。结果显示:杀螨醚、虫螨畏、灭螨猛、杀螨酯和乙酯杀螨醇标准曲线的线性范围均为0.01~5.0 mg·L^-1,检出限(3S/N)依次为0.004,0.006,0.008,0.010,0.008 mg·kg^-1;在3个不同加标浓度水平下,空白土壤样品中5种杀螨剂的回收率为84.8%~99.6%,测定值的相对标准偏差(n=6)为2.1%~4.0%;方法用于5份实际土壤样品分析,其中杀螨醚、灭螨猛、杀螨酯和乙酯杀螨醇被检出,检出量为0.003~0.007 mg·kg^-1。

5 g of the pretreated soil sample was put into the Soxhlet extractor and extracted with dichloromethane as extraction solvent. The extracted solution was purified by HLB solid phase extraction small column and eluted with methanol. Then the all eluate collected was blown to nearly dry with nitrogen and made its volume up to 1 mL with methanol. The solution was analyzed by gas chromatography-tandem mass spectrometer in multi-reaction monitoring mode, and external standard method was used for quantitative analysis. As shown by the results, linear ranges of the standard curves of oxythane, methacrifos, chinomethionate, chlorfenson and chlorobenzilate were 0.01-5.0 mg·L^-1, with detection limits (3S/N) of 0.004, 0.006, 0.008, 0.010 mg·kg^-1 and 0.008 mg·kg^-1, respectively. Values of recovery of 5 acaricides at 3 spiked concentration levels were in the range of 84.8%-99.6% on the blank soil sample, and RSDs (n=6) of the determined values were ranged from 2.1% to 4.0%. This method was used to analyze the 5 actual soil samples, and oxythane, chinomethionate, chlorfenson and chlorobenzilate were detected, with detection amounts in the range of 0.003-0.007 mg·kg^-1.