FIA-FAAS DETERMINATION OF TRACE AMOUNTS OF PLATINUM——ON LINE PRECONCENTRATION ON MICRO-COLUMN

The PTFE microcolumn was packed with α-aminopyridine resin (size 0.12～0.15mm) to preconcentrate trace amounts of Pt(Ⅳ) from an acetate buffer solution of pH 3～4. A mixed solution of 2mol·L -1 HCl+0 3mol·L -1 NaClO_4 was used as eluent. The concentration factor was found to be 30 when the sampling volume was 15.2ml and the eluent volume was 0.27ml. The flow-rate of the sample solution was set at 7.6ml·min -1. The sampling frequency was 28 times per hour. Pt(Ⅳ) in the eluent was finally determined by FAAS. Detection limit (3σ) of this method was found to be 5.2μg·L -1. Average RSD % obtained by testing at concentration level of 1μg·ml -1 for 11 times, was 1.4%.