Abstract
The determination of platinum by inductively coupled plasma atomic emission spectrometry (ICP-AES) after solvent extraction with potassium O-alkyl dithiocarbonate(KRX) was investigated. The optimum conditions of ICP-AES were as follow: incident power, observation height of measurement, coolant gas flow rate, plasma gas flow rate, carrier gas flow rate and wavelength were 1.0 kW, 13 mm above the coil, 16.0, 1.6, 0.6 l/min and 214.42 nm respectively. Among KRX examined, potassium O-butyl dithiocarbonate (KBuX) was the most suitable complexing reagent. The platinum-O-alkyl dithiocarbonate complex was quantitatively extracted into xylene. The optimum pH was between 5.2 and 6.2. KBuX concentration more than 0.001 mol·dm-3 was required. The coexistence of 5 mg of Ni(II) decreased the emission signal intensity of platinum, but 1000 mg of Na(I), 100 mg of Al(III), 20 mg of Mg(II), 5 mg of Ce(IV), O.5 mg of K(I), Cu(II), Ni(II), Pd(II), Rh(II), Ir(III), Au(III) and Si(IV) showed no significant interference on the determination of platinum. The relative standard deviation for ten measurements in this method ranged from 1.4 to 1.5% in the determination of 10.0, 30.0 and 50.0 μg of platinum.
This method was applied to the determinatio n of platinum in catalysts and the analytical results were in excellent agreement with the reference'Avalues.
