Evaluation of a method for the determination of total cadmium, lead and nickel in foodstuffs using measurement by flame atomic-absorption spectrophotometry

Abstract

A method is described for the determination of cadmium, lead and nickel in foodstuffs. Organic matter is destroyed using a wet-digestion procedure and the three elements are concentrated by chelation with a mixture of ammonium tetramethylenedithiocarbamate and diethylammonium diethyldithiocarbamate and extraction from an acidic solution with 4-methylpentan-2-one; measurement is by flame atomic-absorption spectrophotometry. The accuracy of the method has been assessed, ionic interferences noted and standard deviations calculated both for the method itself and the method in application, for levels likely to be encountered in foodstuffs. Confidence intervals and detection limits have been deduced from the results obtained for each element, completing the qualification of the procedure.