Ion-exchange concentration on a chelating resin and atomic absorption spectrophotometric determination of heavy metals in geochemical samples

An ion-exchange concentration-atomic absorption spectrophotometric method was described for the separation and determination of heavy metals including chromium, manganese, iron, cobalt, nickel, copper, zinc, cadmium and lead in materials of geochemical interest. The distribution coefficients, Ksub(d), of heavy metal ions for iminodiacetate type chelating resin (Chelex-100) were measured by a batch method as a function of pH. The values for all the metal ions investigated depend markedly on the pH value. Although the individual values differ considerably one from another, they increase very steeply with increasing pH value. This can be ascribed to the increasing ionization of the