Calibrationless determination of lead in waste water samples by flow-through stripping chronopotentiometry

A flow-through stripping chronopotentiometry has been used for calibrationless determination of lead in wastewater samples. Lead was deposited on glassy carbon porous electrode, previously coated with Nafion and mercury, applying a potentiostatic mode, and then stripped applying a constant current. The procedure was validated and applied to the analysis of wastewater samples from electroplating plant. Accuracy of the results was confirmed by graphite furnace atomic absorption spectrometry. LOD and LOQ for 5 mL-in-volume sample were 0.07 μg L-1 and 0.22 μg L-1, respectively. Linear response was obtained for the analyte concentration range 0.5-2000 μg L-1 for sample volumes from 0.5 to 5.0 mL. Repeatability and reproducibility were 1.1% and 3.7%, respectively. (authors)