2′,7′-二氯荧光素荧光光谱法测定饲料中微量总砷

Fluorimetric Determination of Trace Amount of Arsenic in Feed with 2′,7′-Dichlorofluorecein

在 p H=7.5缓冲溶液中 ,I2 与 2′,7′-二氯荧光素反应 ,引起荧光猝灭 ,加入 As3 + 与 I2 反应 ,体系荧光增强 ,基此建立了荧光光谱法间接测定微量As3 + 的新方法。荧光发射波长为 λem=5 2 0 nm。砷含量在 1 0— 1 0 0 .0 μg/L范围内呈现良好的线性关系 ,回归方程为 ΔIF=0 .4 92 0 + 0 .70 0 5 C(C:μg/L) ,相关系数 r=0 .9980 ;检出限为 1 .0 μg/L。本法用于饲料样品中微量总砷的测定 ,获得满意的结果。

A new fluorimetric method was developed for the determination of trace amounts of arsenic based on the inhibition of As 3+ to fluorescence quenching of I_2 and 2′,7′-dichlorofluorecein as fluorogenic reagent(λ_ em=520nm) in pH=7.50 buffer solution.The linear range of the calibration curve is 10.0—100.0μg/L with equation of ΔI_F=0.7005C(C:μg/L)+0.4920,r=0.9980.The method was applied to the determination of arsenic in feed with satisfactory results.