ONLINE PRECONCENTRATION AND DETERMINATION OF TRACE PLATINUM BY FLOW-INJECTION ATOMIC-ABSORPTION SPECTROMETRY

The analytical performance of a platinum preconcentration method using a 0.01 M HNO3 carrier solution and an alumina microcolumn is discusse d. On-line preconcentration is followed by flame atomic absorption spe ctrometry (FAAS), and off-line preconcentration by graphite furnace at omic absorption spectrometry (GFAAS). The preconcentration factors wer e 600 for FAAS (25 mu l elution volume) and 30 for GFAAS (500 mu l elu tion volume), both with a 15-ml sampling volume. The detection limits in these conditions were 0.02 mg l(-1), and relative standard deviatio n (R.S.D.) of 9% (0.1 mg 1(-1) solution, n = 5) for FAAS and 0.33 mu g l(-1), and a R.S.D. of 7% (5 mu g l(-1) solution n = 5) for GFAAS. Th e proposed method is suitable for platinum determination in natural wa ter samples.