2-mercaptobenzothiazole-bonded silica gel as selective adsorbent for preconcentration of gold, platinum and palladium prior to their simultaneous inductively coupled plasma optical emission spectrometric determination

A 2-mercaptobenzothiazole-bonded silica gel chelating adsorbent(MBTSG) was synthesised by the Mannich reaction between 2-mercaptobenzothiazole and aminopropyl silica gel, and its adsorption characteristics were studied in detail, An(III), Pt-IV and Pd-II can be quantitatively adsorbed by the adsorbent from aqueous solution at pH less than or equal to 5.0 and C-H(+) less than or equal to 6 M. The adsorption capacities of Au-III, Pt-IV and Pd-II were >4.5, >6.5 and >18 mg per gram of dry MBTSG, respectively, The adsorbed metal ions can be readily desorbed with 3% thiourea in 3 M HCl solution, Other metal ions caused little interference in the preconcentration and simultaneous determination of Au-III, Pt-IV and Pd-II by ICP-OES. Concentrations of 2 ppb of An, Pt and Pd can be determined reliably with a preconcentration factor of 250.