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

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.