Trace level determination of lead by flame AAS using on-line separation and preconcentration

A flow injection (FI) on-line preconcentration method was developed for the flame atomic absorption spectrometry (FAAS) determination of trace amounts of lead in alloy samples. Lead was preconcentrated on a minicolumn packed with a poly(aminophosphonic acid) chelating resin (PAPhA), and subsequently eluted using a small volume of hydrochloric acid (2 mol/L) directly into t he nebulizer burner system of the spectrometer. The procedure resulted in a n enhancement factor of 14. A detection limit of 6.3 mug/L (3 sigma) was ob tained using a time-based technique with 30 s preconcentration; a 2.1% RSD was readily achieved for 11 measurements of 50 mug/L Pb. The sample through put was about 80/h. The procedure was applied to the determination of lead in alloy samples with high tolerance to interferences,and the results obtai ned for standard reference materials were in good agree ment with the certi fied values.