Electrochemical generation of volatile Pb species on Au/Hg cathodes as a sample introduction technique in the determination of Pb by atomic absorption spectroscopy

We have used amalgamated Au cathodes for electrochemical generation of volatile lead hydride, PbH4. An electrochemical cell was coupled to an atomic absorption spectrometer, using the lead absorbance signal as a measure of production of volatile Pb hydride and univariate approach to optimize operational parameters. Cathode of Au/Hg showed better mechanical resistance and better tolerance to interfering ions than other traditional cathodes. Under optimized conditions, a 0.02 µg.L-1 (Sbl + 3s) detection limit for Pb (II) is reported in aqueous solutions. The accuracy of the method was determined by quantification of Pb in a river water material reference (SLRS-2/National Research Council Canada).