水体和甘蓝及土壤中毒死蜱残留检测方法

研究运用不同的样品前处理方式,在装配火焰光度检测器的气相色谱(GC-FPD)上检测,建立了有机磷杀虫剂毒死蜱在水样、土壤和甘蓝中的残留测定方法.研究表明,不同样品中的毒死蜱残留采用本文中介绍的前处理方法是可行的,用石油醚盐析提取和净化水样中毒死蜱,采用丙酮振荡提取甘蓝中毒死蜱,选用索氏提取法提取土壤中毒死蜱,并经液液分配净化后,采用OV-101大口径毛细管柱(30 m×0.53 mm×1.0μm),在装配火焰光度检测器(FPD和磷滤光片)的气相色谱上测定.该分析方法下,毒死蜱的保留时间为1.74 min,线性范围在1.0×10-11—1.0×10-8g之间,其线性相关系数为0.9998,最小检出量为2.0×10-12g.在设定的较低添加浓度的条件下,毒死蜱在水样、土壤与甘蓝上的添加回收率为80%—120%,变异系数均小于5%.该分析方法灵敏、准确、操作简便,适合水样、甘蓝和土壤中低浓度毒死蜱的残留检测.

Determination of chlorpyrifos residues in water,cabbage and soil by GC-FPD

Using gas chromatography-flame photometric detection(GC-FPD),a method was developed for the analysis of organophosphorus pesticide chlorpyrifos in water,soil and cabbage.The chlorpyrifos residue in water was extracted and purified by petroleum ether and liquid-liquid extraction.The chlorpyrifos residue in cabbage was extracted with acetone and the chlorpyrifos residue in soil was extracted by the Soxhlet method with acetone.After clean up by liquid-liquid distribution,it was determinated by GC-FPD equipped with OV-101(100% dimethyl polysiloxane)column(30 m×0.53 mm×1.0 μm).The retention time of chlorpyrifos was 1.74 min;the linearity range of chlorpyrifos was between 1.0×10-11 and 1.0×10-8 g;the correlation coefficient was 0.9998;the limits of detection was 2.0×10-12 g.Average recovery rates of chlorpyrifos in these samples ranged from 80% to 120% with coefficient of variation from 1.19% to 4.40%.The method is sensitive and operated easily to detect low levels of chlorpyrifos in the water,cabbage and soil.