A comparison of a spectrophotometric (quercetin) method and an atomic-absorption method for the determination of tin in food

Abstract

Procedures for the determination of tin in food, which involve a spectrophotometric method (with the quercetin-tin complex) and an atomic-absorption method, are described. The precision of the complete methods and of the individual analytical steps required is evaluated, and the parameters that influence the precision are discussed.

It is concluded that while the spectrophotometric method is to be preferred for very low tin concentrations, for instance, residues of organotin compounds, the two methods are equally useful for the determination of tin in concentrations normally found in canned foods. With both methods recoveries of added tin do not deviate significantly from 100 per cent. within their respective working ranges.