催化动力学荧光法测定环境水样中As(Ⅲ)

Determination of trace As(Ⅲ) in environmental water samples by catalytic fluorescence method

目的:建立环境水样中痕量As(Ⅲ)的动力学荧光测定法。方法:基于硫酸介质中,As(Ⅲ)能催化高碘酸钾氧化藏红T的反应,导致体系的荧光强度急剧减弱,在一定条件下,荧光强度减小值与溶液中As(Ⅲ)浓度成线性,据此建立了一种催化动力学荧光法测定As(Ⅲ)的新方法。结果:方法的线性范围为0.00~0.24μg/ml,检出限4.68×10^(-4)μg/ml,相对标准偏差为1.24%~2.83%(n=11),样品加标回收率93.2%~101.9%。结论:方法灵敏度高、精密度好,用于环境水样中痕量As(Ⅲ)的测定,结果满意。

Objective： To establish a rapid and sensitive method for the analysis of trace As（ Ⅲ） by catalytic fluorescence method. Methods： The results showed that there was a evident catalytic effect of As（Ⅲ ） on the oxidation reaction of Safranine T by Potassium periodate in sulphuric acid medium. The decreased intensity of fluorescence was directly proportional to the concentration of As（ Ⅲ ） under certain conditions. Results： The linear range was 0.00--0.24μg/ml, the detection limit was 4.68 ×10^-4μg/ml, the relative standard deviation was between 1.24 %- 2.83 % （ n = 11 ）, and the recovery were 93.2 %- 101.9 %. Conclusion： The method has the advantage of simplicity, high sensitivity, and had been applied to the determination of trace As（ Ⅲ ） in water to achieve satisfactory results.