A direct method for the determination of lead in beers by differential pulse polarography-anodic stripping voltammetry

In this paper, a fast procedure to determine lead in beers in situ was developed using Differential Pulse Polarography (DPP) and Anodic Stripping Voltammetry (ASV). Lead was deposited by reduction at -900 mV on the surface of the Static Mercury Drop Electrode (SMDE). Then, the preconcentrated metal was re-oxidized by scanning the potential from -900 to %2b100 mV, around -450 mV the signal belonging to lead was identified. The SMDE showed an excellent linear behavior at the concentration range, from 0.04975 to 0.4761 mg L-1 (r=0.9986). The limit of detection (LOD) found was 0.026 mgL-1 and the limit of quantification (LOQ) 0.087 mgL-1, both of these values are under the maximum allowed concentration of lead (0.5 mg L-1) in alcoholic beverages established by Mexican law NOM-142-SSA1-1995.

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