基于在盐酸溶液中,乐果在氢氧化钠介质中的水解产物被铈(Ⅳ)氧化而产生强烈的化学发光,并结合应用顺序注射技术,提出了SI-CL法测定环境水样中痕量乐果的方法。采用三区带进样模式,将试剂按以下方式组合:(a) 0.3 mol·L-1氢氧化钠溶液与8 g·L-1 HPC溶液混合,(b) 水样及(c) 0.035 mol·L-1硫酸铈铵溶液与1.2 mol·L-1盐酸溶液混合。其进样体积依次为(a) 200 μL,(b) 200 μL和(c) 80 μL。化学发光强度与乐果的质量浓度在1~100 μg·L-1和100~800 μg·L-1两个范围内呈线性关系。检出限(3σ)为0.17 μg·L-1。回收率在85.7%~119%之间。

Based on the fact that in an acidic medium of HCl, intense chemiluminescence (CL) was induced by the oxidative reaction between Ce(Ⅳ) and the hydrolyzate of dimethoate produced in an alkaline solution of NaOH, and on the application of sequential injection (SI) technique, a method of SI-CL for determination of traces of dimethoate in environmental water samples was proposed. The tri-zone injection mode was used and the related reagents and water sample were combined in 3 portions as follws: (a) 0.3 mol·L-1 NaOH solution and 8 g·L-1 HPC solution, (b) water sample and (c) 0.035 mol·L-1 Ce(Ⅳ) solution and 1.2 mol·L-1 HCl solution, with their injection volumes of (a) 200 μL, (b) 200 μL and (c) 80 μL. Values of intensity of CL was found to keep linear relationship with mass concentration of dimethoate in 2 ranges of 1 to 100 μg·L-1 and 100 to 800 μg·L-1, with detection limit (3σ) of 0.17 μg·L-1. Values of recovery found were in the range of 85.7% to 119%.