New techniques for the digestion of biological materials — application to the determination of tin, iron and lead in canned foods

Abstract

SummaryA new technique for the digestion of biological materials has been developed and this has been applied to the determination of trace metals in canned foods. It is based on sample digestion in concentrated acid under pressure in a disposable polystyrene container. The digest can be analysed directly by atomic absorption or plasma emission and has the advantages of simplicity, high sensitivity (low blank value), rapid batch sample throughout rate, economy and suitability for automation. Various foods have been classified empirically into three groups on the basis of the ease with which they can be decomposed chemically to a form suitable for analysis. After classification, preparation follows one of two different procedures depending on the elements to be determined.The system has been verified for tin, iron and lead by comparison with other more conventional procedures.