Three pyrethroids (bifenthrin, cypermethrin and deltamethrin) in soil were determined by hollow fiber liquid-phase microextraction (HF-LPME) coupled gas chromatography-mass spectrometry (GC-MS). The sample preparation and extraction conditions were optimized, and the optimum conditions obtained as follows; ratio of soil to water was 1:3, pH value was 4, ultrasonic time was 5 min, extraction solvent was cyclohexane, extraction temperature was 25 ℃ , stirring speed was 900 r/min, and extraction time was 20 min. After extraction, 1 μL organic solvent was introduced to GC/MS for analysis. Under the optimize condition, using selected ion mode (SIM), the linear range for bifenthrin, cypermethrin and deltamethrin was 0. 01 - 25 mg/kg, 0. 5 - 50 mg/kg and 0. 5-50 mg/kg, respectively. The limits of detection (LOD) were 0. 003, 0. 020 and 0. 040 mg/kg, and the relative standard deviations(RSD) were 4. 3%, 4. 7% and 8. 6%. The results demonstrated that the method was feasible for the determination of pyrethroids in soil.%采用中空纤维膜-液相微萃取-气相色谱/质谱法测定土壤中3种拟除虫菊酯类农药(联苯菊酯、氯氰菊酯、溴氰菊酯).实验优化的样品制备和萃取条件为:土壤与水的质量比为1:3,pH=4,超声时间为5 min,萃取剂为环己烷,萃取温度为25℃,搅拌速率为900 r/min,萃取时间为20 min.萃取后取1 μL萃取剂进行色谱分析.在此条件下,当采用SIM模式时,测得土壤中联苯菊酯、氯氰菊酯和溴氰菊酯的线性范围分别为0.01～25 mg/kg,0.5～50 mg/kg和0.5～50 mg/kg;检出限分别为0.003,0.020和0.040 mg/kg;相对标准偏差分别为4.3％,4.7％和8.6％.本方法可用于土壤中拟除虫菊酯类物质的快速测定.
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