A flow injection system for lead determination at concentration levels of mg L-1 is proposed using Hydride Generation Atomic Absorption Spectrometry (HG-AAS). To do this, 8.0% (m/v) (NH4)2S2O8 is employed as the oxidizing agent, and 100 µL of sample and 100 µL of 3.0% (m/v) NaBH4 are simultaneously injected into two carrier streams, 0.5% (m/v) tartaric acid and de-ionized water, respectively. A sampling rate of about 150 determinations per hour was achieved, requiring 15 mL of NaBH4 and a waste generation of 250 mL. The detection of limit of 0.3 µg L-1 for Pb was achieved and the relative standard deviation of 3.0% for 10 µg L-1 Pb was obtained. The method was shown to be satisfactory for determination of traces of Pb in certified reference material of drinking waters and in natural water samples.
lead; water; flow-injection hydride generation; atomic absorption spectrometry
