Determination of eleven metals in small samples of blood by sequential solvent extraction and atomic-absorption spectrophotometry

Abstract

A method is described for the determination of eleven metals in a 1-ml solution of an oxidised blood sample. The metals iron, copper, bismuth, zinc, cadmium, lead, cobalt, nickel, manganese, strontium and lithium are selectively extracted into small (0·30 to 0·50 ml) volumes of isobutyl methyl ketone as their chelates or ion-association complexes, and are determined in the organic phases by atomic-absorption spectrophotometry. The enhancement effect of the organic solvent combined with the extraction and concentration of the metals results in average sensitivity increases of seven times that obtained by a direct determination on the aqueous solutions.

The recovery of the metals added to blood is quantitative and, with two exceptions (lead and bismuth), a precision of better than 8 per cent. can be achieved at the 0·1 p.p.m. level.

The results are given of an application of the method to a study of the problem of metal ingestion by children who have pica.