蔬菜中有机磷农药辛硫磷的化学发光分析研究

Chemiluminescence Assay of Organophosphorous Pesticides Phoxim in Vegetable

研究发现，在碱性介质中，无机盐氯化钠显著增强有机磷农药辛硫磷在鲁米诺-H2O2体系中的化学发光信号，据此建立了测定辛硫磷的化学发光新方法并探讨了该化学发光反应的可能机理。在鲁米诺分析液浓度为5×10^-4mol／L，H2O2溶液浓度为0．3mol／L，NaCl浓度为4mol／L，pH值为13的条件下，辛硫磷的浓度在1．0×10^-5～1．0×10^-3g／L范围内与化学发光强度呈良好的线性关系；检出限为5．4×10^-6g／L；对浓度为5．0×10^-4g,／L的辛硫磷进行11次平行测定，相对标准偏差为4．6％；添加3水平（0．01～1．0mg／kg）的回收率为86％～106％。本方法用于蔬菜中辛硫磷残留量的测定，结果与气相色谱法基本一致。

A novel chemiluminescence （CL） method for the determination of phoxim has been developed. It is based on the reaction of phoxim with luminal-H2O2 in alkaline medium with sodium chloride being enhancer. Under the optimal conditions （ the concentration of lumionl was 5 × 10^-4 mol/L , the concentration of H2O2 was 0.3 mol/L, the concentration of NaCl was 4 mol/L and pH was 13 ）, the CL intensity was linear to the concentration of phoxim in the range of 1.0 × 10^-5 - 1.0 × 10^-3 g/L, with a detection limit of 5.4 × 10^-6 g/L. The relative standard deviation was 4.6% for 5.0 × 10^-4g/L phoxim （n = 11 ） and the recovery was between 86% - 106%. This method has been successfully applied to the determination of phoxim residue in vegetable samples and the results were almost identical with the GC method results.