Separation and Concentration of Tin(IV) by Co-precipitation with Gallium Phosphate for Electrothermal Atomization Atomic Absorption Spectrometry

Abstract

Abstract Gallium phosphate co-precipitates quantitatively 0.5—5.0 μg of tin(IV) from 100 to 500 cm3 of a sample solution at pH 3.0—6.0. After co-precipitation, tin(IV) can be sensitively determined by electrothermal atomization atomic absorption spectrometry. The atomic absorbance of tin(IV) increases by about 1.7 times in the presence of gallium. Although many ions interfere with the determination, interference from the majority can be eliminated by using a graphite furnace impregnated with hafnium, which also improves the sensitivity and reproducibility of the determination. Tellurium(IV) and zirconium(IV) interfere seriously. The calibration curve is linear from 0.02 to 0.20 μg cm−3 for tin(IV), and the detection limit (signal/noise = 2) is 0.23 ng cm−3 of tin(IV) in 500 cm3 of the initial sample solution. This method is applicable to the analyses of water samples for tin(IV).