固相萃取-气相色谱法测定饮用水中12种农药
GC Determination of 12 Pesticides in Drinking Water with Solid Phase Extraction
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摘要: 提出了固相萃取-气相色谱法测定饮用水中12种农药残留量的方法。取水样250 mL过固相萃取柱,用乙酸乙酯、正己烷各5 mL洗脱,经无水硫酸钠脱水,采用DB-5MS毛细管色谱柱分离,电子捕获检测器检测。溴氢菊酯的线性范围为0.05~0.5 mg·L-1,其他农药的线性范围均在0.01~0.1 mg·L-1。溴氰菊酯的检出限为24.2 ng·L-1,其他农药的检出限均低于10 ng·L-1。12种农药的加标回收率在70.0%~110%之间,相对标准偏差(n=6)均小于10%。Abstract: GC with solid-phase extraction was applied to the determination of 12 pesticides in drinking water. Water sample (250 mL) was extracted on C18 solid phase extraction column (SPE). The pesticides on SPE column were eluted with ethyl acetate (5 mL) and n-hexane (5 mL) successvely. Anhydrous Na2SO4 was used for dehydration. The analytes were separated on DB-5MS capillary column and detected by ECD. Linearity range of decamethrin was 0.05-0.5 mg·L-1, and all the other pesticides′ were found between of 0.01-0.1 mg·L-1. Detection limit of the method for decamethrin was 24.2 ng·L-1 and other pesticides′ were below 10 ng·L-1. Values of average recovery of 12 pesticides in water ranged from 70.0% to 110%, and RSD (n=6) were less than 10%.