Study on solid phase extraction and spectrophotometric determination of platinum with 2-(p-carboxylphenylazo) benzothiazole

Based on the color reaction of 2-(p-carboxylphenylazo) benzothiazole(CPABT) with platinum(Ⅳ) and the solid phase extraction of its colored complex with C8 cartridge,a new method for the determination of platinum was studied.In the presence of Tween-80 and HAc-NaAc buffer solution(pH 3.8～5.5).CPABT reacts with platinum(Ⅳ) to form a stable 1∶1 complex.The colored complex was extracted by C8 cartridge and the retained chelate was eluted from cartridge with DMF,then determined by spectrophotometry at 508 nm.Beer′s law is obeyed in range of 0.1～1.2 μg/mL and e is 2.29×105 L·mol-1·cm-1.The method was applied to determination of the trace platinum in the catalysts with a satisfactory result.