Trace lead monitoring in waters by potentiometric stripping analysis

Abstract

A monitoring study on the presence of lead traces was realized on aqueous matrices by potentiometric stripping analysis. Assimilation of metal traces from environment, foods and drugs is an important process which contributes to metal bioaccumulation in the body. The method involves the direct acidification of the sample (20 mL) without further pre-treatments. The electrolysis time was fixed at 180 s, the potential at −900 mV, the electrolysis stripping time was maintained in 10 s. Lead solutions were used as internal standard to elaborate the calibration curve (R 2 >95%). The limit of quantitation resulted of 5 μg.L−1 . The method was validated on several water samples spiked with known amounts of lead. The method was applied to five Italian bottled water and eighteen water sources in the territory of Serra St. Bruno, Calabria, Italy, revealing the presence of traces of the metal in some of them.