The determination of lead in foods by atomic-absorption spectrophotometry

Publisher Website
Google Scholar
Abstract
Rapid procedures for the determination of lead in foods by an organic extraction technique and atomic-absorption spectrophotometry are described. The food sample can be dry ashed or digested by using sulphuric acid and hydrogen peroxide. In the latter instance, digestion need not be complete. Lead is extracted from acidic solutions (either the dissolved ashes or the residual solution after acid digestion) into xylene as its diethylammonium diethyldithiocarbamate chelate, and then determined by use of atomic-absorption spectrophotometry. Large amounts of iron and tin do not interfere in the determination. In a 10-g sample, 0·02 p.p.m. of lead can be detected. The standard deviation in the range from 0·2 to 1·0 p.p.m. of lead is about 0·02 p.p.m. Certain products do not require preliminary digestion; in these instances lead is extracted directly from the acidified sample. Liquids, beverages and many canned foods can be monitored very rapidly in this way. The chelate-solvent combination used in this method is more convenient than the ammonium tetramethylenedithiocarbamate-isobutyl methyl ketone system. The method is applicable also to metals other than lead; its use for cadmium has been demonstrated successfully.

This publication has 0 references indexed in Scilit: