分光光度法测定果蔬中残杀威残留量

Spectrophotometric Determination of Residual Amount of Propoxur in Fruit and Vegetable

在碱性条件下残杀威水解生成酚盐,在盐酸介质中对氨基苯磺酸与亚硝酸根发生重氮化反应,上述所得酚盐和重氮化产物在氨性溶液中偶联生成偶氮染料,此偶联产物的最大吸收波长为427nm,据此提出了分光光度法测定果蔬中残杀威含量的方法。残杀威的质量浓度在0.17～2.04mg·L-1范围内与其吸光度呈线性关系,检出限(3s/k)为0.03mg·L-1。方法用于测定果蔬中残杀威的含量,相对标准偏差(n=5)在0.3%～0.7%之间,加标平均回收率为96%。

In an ammoniaeal solution, azo dye was formed between phenate （produced by hydrolysis of propoxur in an alkaline medium） and diazo compound （produced by diazotization between sulfanilic acid and nitrite）, with its absorption max. at the wavelength of 427 nrn, Based on these facts, a spectrophotometric method for determination of propoxur in fruit and vegetable was proposed. Linear relationship between the values of absorbance and mass concentration of propoxur was obtained in the range of 0. 17-2. 04 mg · L-1 , with detection limit （3s/k） of 0. 03 mg · L^-1. The present method was used in the analysis of samples of fruit and vegetable, giving values of RSD＇s （n=5） in the range of 0. 30%-0. 7%. Test for recovery was performed by standard addition method, result of average recovery obtained was 96 %.