前处理过程中采用活性炭过滤对蔬菜有机磷农残测定的影响

[目的]了解活性炭对蔬菜有机磷农药残留测定的影响。[方法]在西葫芦样品中添加一定量的7种有机磷农药混合标准溶液制成一定浓度的模拟加标样品,进行活性炭过滤和不使用活性炭过滤2种前处理,气相色谱法测定蔬菜中有机磷农药残留。[结果]活性炭过滤处理的7种有机磷农药的回收率都低于不使用活性炭处理。活性炭过滤后,甲胺磷、乙酰甲胺磷、甲拌磷和毒死蜱的回收率都低于70%。不使用活性炭过滤处理的相对标准偏差为3.9%~7.7%,活性炭过滤处理的相对标准偏差为5.3%~18.2%,均符合要求。[结论]在前处理过程中采用活性炭过滤,会降低有机磷的回收率,影响测定结果,所以尽量不用活性炭。

Effect of Using Activated Carbon Filtration in Pretreatment Process on the Determination of Organophosphorus Pesticide Residue in Vegetables

[Objective] The aim was to know about the effect of activated carbon on the determination of organophosphorous pesticide residue in vegetables.[Method] The simulated samples with standard at some concn.were perpared by adding some dosage of mixed standard solution of 7 kinds of organophosphorous pesticides into summer squash samples and the prepared samples were treated by activated carbon filtration and filtration without activated carbon.The organophosphorous pesticide residue in vegetables was determined by gas chromatography(GC).[Result] The recoveries of 7 kinds of organophosphorous pesticides treated by activated carbon filtration were lower than that of them treated by filtration without activated carbon.The recoveries of methamidophos,acephate,phorate and chlorpyrifos were lower than 70% after activated carbon filtration.The relative standard deviation(RSD) of treatment by filtration without activated carbon was 3.9%-7.7% and that of treatment by activated carbon filtration was 5.3%-18.2%,both of them satisfied the requirements.[Conclusion] Using activated carbon filtration in pretreatment process would reduce organophosphorous recovery and affect determination results.So the usage of activated carbon should be avoided as possible.