变色酸2R共振光散射光谱法测定农药甲氰菊酯

Determination of Fenpropathrin with Chromotrope 2R by Resonance Light Scattering Method

在pH1.7的HCl-NaAc缓冲溶液中,变色酸2R在421 nm波长处产生共振散射信号,甲氰菊酯的加入使该波长处的散射强度明显增强。当变色酸2R用量为1.2 mL时,甲氰菊酯-变色酸2R反应体系的共振散射信号最强,且散射强度增加值与甲氰菊酯的质量浓度在0.03～0.66μg.mL-1范围内呈线性关系,甲氰菊酯的质量浓度检出限为0.025μg.mL-1。据此,建立共振散射光谱法测定甲氰菊酯,该方法用于白菜和苹果等样品中甲氰菊酯的测定,结果满意。

It was found that in a HCl-NaAc buffer solution of pH 1.7,the intensity of the resonance light scattering（RLS） at 421nm was enhanced significantly due to the reaction of fenpropathrin with chromotrope 2R.When the amount of chromotrope 2R was 1.2 mL in the solution,the maximum resonance scattering signal appeared in the reaction system of fenpropathrin with chromotrope 2R,and the increasing value of RLS intensity was proportional to the concentration of fenpropathrin.The linear range was 0.03-0.66 μg·mL-1,and the limit of detection was 0.025 μg·mL-1.The method was simple,rapid and sensitive.The proposed method was applied successfully for the determination of fenpropathrin in the apple and cabbage samples.