Determination of lead and cadmium in foods by anodic stripping voltammetry: I. Development of method

Food samples are dry ashed at 500 +/- 50 degrees C with a 10% aqueous K2SO4 solution used as an ashing aid. The ashed sample is dissolved in 50 mL 2% HNO3. Anodic stripping voltammetry is used to determine lead and cadmium in a mixture of the sample solution and an acetate electrolyte at pH 4.3 +/- 0.3. The estimated quantitation limits, based on a 10 g food sample, are 0.005 ppm for cadmium and 0.010 ppm for lead.