Potentiometric stripping analysis for lead in urine

Potentiometric stripping analysis is based on the preconcentration of analytes by means of potentiostatic reduction and amalgamation at a thin-film mercury electrode. After preconcentration, the potentiostatic circuitry is disconnected and the amalgamated metals are oxidized either by mercury(II) ions or by dissolved oxygen. Lead can be determined in acidified urine samples by potentiometric stripping analysis after the addition of Triton X-100. In deaerated samples the detection limit is 1 μg l^?1, and in non-deaerated samples 12 μg l^t-1, the preconcentration time being 16 min.