SIMULTANEOUS DETERMINATION OF TOTAL AND FREE METAL-ION CONCENTRATION IN SOLUTION BY SORPTION ON IMINODIACETATE RESIN

A method for determining the total concentration of a metal ion origin ally present in a solution (c(tot)) and the ratio of total to free met al ion (Z(M)) is proposed. It consists of putting different aliquots o f the sample (V) in contact with the resin (re) in batch, by keeping t he acidity constant, and determining the concentration of the sorbed m etal ion c. Then 1/c is plotted against V/w, and c(tot) and Z(M) are c alculated from the straight line obtained. The chemical model that all ows evaluation of the ratio of total to free metal ion is illustrated and discussed. Some synthetic systems are examined to demonstrate the validity of the procedure.