Evaluation of the analytical performance of flow injection-Flame atomic absorption spectrometry

Analytical performance of flow injection-flame atomic absorption spectrometry was evaluated in terms of precision and sensitivity. For direct aqueous-solution introduction and alcoholic-eluate introduction after on-line sorbent extraction, the influence of the interfacing parameters was investigated, including the nebulizer uptake rate, sample-introduced flow rate and coupling tube length. High sensitivity could be achieved by the exploitation of the synergetic effect of both sample pumping and aspirating processes. A low nebulizer uptake rate combined with a high flow rate of the introduced sample zone produced the optimum precision better than 2% for peak-height measurements, the optimum rates being dependent on the nebulization characteristics of the solvent used. Precision and sensitivity deteriorate with increasing length of the coupling tube.