On-line 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 discussed. On-line preconcentration is followed by flame atomic absorption spectrometry (FAAS), and off-line preconcentration by graphite furnace atomic absorption spectrometry (GFAAS). The preconcentration factors were 600 for FAAS (25 μl elution volume) and 30 for GFAAS (500 μl elution volume), both with a 15-ml sampling volume. The detection limits in these conditions were 0.02 mg l−1, and relative standard deviation (R.S.D.) of 9% (0.1 mg l−1 solution, n = 5) for FAAS and 0.33 μg l−1, and a R.S.D. of 7% (5 μg l−1 solution n = 5) for GFAAS. The proposed method is suitable for platinum determination in natural water samples.