单一溶剂处理-气相色谱测定杭白菊中残留含磷有机农药

GC Determination of Residual Organophosphorus Pesticides in Hangzhou White Chrysanthemum by Treatment of Samples with Single Extractant

单独用丙酮作为溶剂提取杭白菊样品中残留的含磷有机农药。所得提取液经CARB/NH2固相萃取柱净化后，在30℃旋转蒸发浓缩至1～2mL，再用吹氮方法进一步浓缩至0．4mL，最后将此丙酮溶液定容至0．5mL，供气相色谱测定用。在DB-1701石英毛细管色谱柱上，8种农药达到很好分离并用氮磷检测器进行测定。测得8种农药的工作曲线线性范围均在0．05～5．0mg·L^-1。以内，8种农药的检出限（3S／N）在0．009-0．028μg·g^-1之间。对方法的精密度和回收率作了试验，测得其相对标准偏差（n=6）在5．45％～7．27％之间，回收率在67．3％～104．0％之间。

Residual amounts of organophosphorus pesticides in samples of Hangzhou white chrysanthemum were extracted with acetone singly, and the extract obtained were purified by the CARB/NH2 SPE column. Eluate from the column was concentrated to 1 - 2 mL by rotary evaporation at 30 ℃ and then to ca. 0. 4 mL by N2- blowing. After making up to 0. 5 mL, the solution in acetone was used for GC deterrnination By using the DB-1701 quartz capillary chromatographic column, 8 organophosphorus pesticides were separated and determined by NPD. Ranges of linearity of the working curves for these 8 pesticides were kept within 5.0 mg·L^-1, and the values of detection limit （3S/N） found were in the range of 0. 009-0. 028 μg·g^-1. Precision and recovery of the method were tested, and values of RSD＇s （n=6） and of recovery found were in the ranges of 5.45%-7. 27% and 67. 3%- 104.0% respectively.