鲁米诺-过氧化氢体系流动注射化学发光法测定乐果

The Determination of Dimethoate by Flow Injection Chemiluminescence Method in Luminol-H_2O_2 System

基于有机磷农药乐果与碱性鲁米诺-过氧化氢体系的化学发光反应,直接对乐果进行检测,并对反应条件进行优化,据此建立了快速测定微量乐果的流动注射化学发光分析法.该方法的线性范围为1.0×10-8-1.0×10-5g/mL,对1.0×10-6g/mL的乐果标准溶液平行测定11次,相对标准偏差为2.1%,3σ检出限为8.0×10-9g/mL,加标回收率为96.4%-103.5%.此法用于大米中乐果残留量的测定,结果令人满意.

A simple and fast flow-injection chemiluminescence （CL） method for the direct determination of dimethoate is described in this paper. It is based on the reaction of dimethoate with luminol-H2O2 in the alkaline medium（ pH 12.0-12.5 ）. And the reaction conditions are optimized. Under the optimal conditions, there is a linear relation between the CL intensity aud the concentration of dimethoate in the range of 1. 0× 10^-8-1.0 ×10^-5 g/mL （r = 0. 999 1 ）. The relative standard deviation（RSD） is 2.1% in 1.0 ×10^-6 g/ mL dimethoate solutions （n = 11 ） with a detection limit （3σ） of 8.0× 10^-9 g/mL, and the satisfactory recovery is between 96.4%- 103.5%. This method has been successfully applied to the determination of trace dimethoate residue in rice sample. The result is satisfactory.