变色酸2R-β-环糊精体系共振光散射光谱法测定农药氰戊菊酯

Determination of Fenvalerate by Resonance Scattering Spectrometry Based on the Reaction with Chromotropic Acid 2R and β-Cyclodextrin

在pH 2.87的B-R缓冲溶液中,氰戊菊酯与变色酸2R反应,在423nm波长处产生稍有增强而稳定的共振散射信号,而β-环糊精的加入进一步明显敏化该共振光散射信号,且散射强度与氰戊菊酯的质量浓度在0.02～0.50mg·L^(-1)范围内呈线性关系,其检出限(S/N=3)为0.016mg·L^(-1)。该方法用于地面水、果品及蔬菜等样品中氰戊菊酯的测定,测得回收率在86.0%～113.0%之间,测得结果的相对标准偏差(n=5)在1.6%～6.0%之间。

It was found that in a B-R buffer solution of pH 2. 87, intensity of the resonance scattering at 423 nm due to the reaction between fenvalerate （FVR） and chromotropie acid 2R （CTA 2R） was enhanced significantly by the presence of β-cyclodextrin （β-CD）, and that linear relationship between magnitude of intensity of the resonance scattering signal and concentration of FVR was obtained in the range of 0. 02-0. 50 mg· L^-1 , with detection limit of 0. 016 mg · L^-1. The proposed method has been applied to the determination of FVR in some samples of surface water, fruits and vegetable, giving values of recovery in the range of 86. 0%-113.0%, and of RSD＇s （n=） in the range 1.6%-6.0 %.