基于荧光猝灭效应的催化荧光光度法测定痕量锡(Ⅳ)

Catalytic Fluorophotometric Determination of Trace Amounts of Tin(Ⅳ) Based on Fluorescence Quenching Effect

摘要: 在邻苯二甲酸氢钾-氢氧化钠介质中,痕量锡催化高碘酸钾氧化3-(3′-甲基苯基)-5-(2′-胂酸基偶氮)若丹宁而荧光猝灭存在明显的催化作用,由此提出了催化动力学荧光光度法测定痕量锡(Ⅳ)的方法.该体系的激发波长为308 nm,发射波长为411 nm,线性范围在0.01 mg·L-1以内,检出限(3S/N)为2.45×10-8g·L-1.采用巯基葡聚糖凝胶分离富集,消除了共存离子的干扰,该方法已应用于铝合金、钢铁和人发中锡的测定.

Abstract: In a phthalate buffer medium of pH 5.2,the oxidation of 3-(3′-methylphenyl)-5-(2′-arsenophenylazo)-rhodanine (MPAPAR in short) by KIO4 was significantly catalyzed by the presence of traces of Sn(Ⅳ),leading to quenching of fluorescence emitted by MPAPAR.Linear relationship between values of decrease in intensity of fluorescence ΔF(F0-F1) and concentration of Sn(Ⅳ) present was found within 0.01 mg·L-1 when measured at the wavelengths of 308 nm (λex) and 411 nm (λem).Detection limit (3S/N) of the method found was 2.45×10-8g·L-1.Traces of Sn(Ⅳ) were separated and enriched by adsorption on sulfhydryl dextrane gel.The proposed method has been used for determination of tin in aluminum alloy,carbon steel and human hair.