Determination of copper in foods by atomic absorption spectrophotometry

Abstract A method for determining copper in a wide range of foods by atomic absorption spectrophotometry is described and shown to be reliable and sensitive. It is shown that, when copper is chelated and extracted into ketone, very high sensitivity may be achieved; copper in aqueous extracts can be determined at a level of 0.003 ppm. The main problem of the method is found to be sample preparation which for many foods is lengthy. Direct sampling, dry ashing and wet oxidation are described and the method of atomic absorption is compared with a colorimetric procedure.