Separation and Spectrophotometric Determination of Platinum (IV) in Natural Waters, Simulated Samples and Prepared Solid Complexes using 1- Phenyl-4-Ethylthiosemicarbazide.

A very simple, highly sensitive and selective spectrophotometric procedure was developed for the determination of platinum(IV). It is based on the reaction at pH . 3 between the synthesized 1-phenyl-4-ethyl thiosemicarbazide (HPETS) and Pt(IV) forming a green complex, Pt(IV): PETS (1:2), that floats quantitatively with oleic acid (HOL) surfactant. It exhibits higher absorbance at . 715 nm in both aqueous and surfactant layers. Beer s law is obeyed up to the concentration 0.39 mg L-1 for a standard aqueous solution of Pt(IV). The molar absorpitivites in aqueous and surfactant are 0.14 x 105 and 0.5 x 105 mol L-1 cm-1, respectively , It is observed that the molar absorpitivity in surfactant layer is higher than that in aqueous. The different analytical parameters affecting the floatation and determination processes were examined. The proposed procedure has been successfully applied to the analysis of Pt(IV) in natural waters, prepared solid complexes and simulated samples. The results obtained agree well with those samples analyzed by atomic absorption spectrophotometry (AAS). Moreover the flotation mechanism is suggested based on some physical and chemical studies on the solid complexes isolated from aqueous and surfactant layers.