Low-temperature sorption-luminescence determination of platinum using silica chemically modified with dithiocarbamate groups

Application of silica chemically modified with dithiocarbamate groups (DTCS) has been proposed for the low-temperature sorption-luminescence determination of platinum. The establishment of a sorption equilibrium in the platinum(IV) and platinum(II) extraction with DTCS from hydrochloric acid solutions takes 20 and 2 min, respectively. If the duration of the phase contact is optimal, the recovery achieves 99% in the acidity range from 4 M of HCl to pH 5. The sorption of platinum(IV) and platinum(II) results in the formation of coordination compounds of platinum(II) on the surface of the adsorbent which are luminescent in ultraviolet light when frozen (77 K). A procedure has been developed for low-temperature sorption-luminescence determination of platinum with the detection limit of 0.5 mu g of platinum per 0.1 g of the adsorbent and linearity of the calibration curve to 25 mu g/0.1 g. The developed procedure has been applied to the determination of platinum in the samples of alumoplatinum catalyst.