EVALUATION OF THE ANALYTICAL PERFORMANCE OF FLOW-INJECTION - FLAME ATOMIC-ABSORPTION SPECTROMETRY

Analytical performance of flow injection - flame atomic absorption spe ctrometry was evaluated in terms of precision and sensitivity. For dir ect aqueous-solution introduction and alcoholic-eluate introduction af ter on-line sorbent extraction, the influence of the interfacing param eters was investigated, including the nebulizer uptake rate, sample-in troduced 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 opti mum precision better than 2% for peak-height measurements, the optimum rates being dependent on the nebulization characteristics of the solv ent used. Precision and sensitivity deteriorate with increasing length of the coupling tube.