Preconcentration neutron activation analysis of trace elements in surface waters by coprecipitation with pyrrolidinedithiocarbamate in the presence of Bi(III)

A simple preconcentration method is described for the simultaneous coprecipitation of Cd(II), Co(II), Cu(II), Mo(VI), U(VI), V(V) and Zn(II) from surface water samples followed by quantitation using neutron activation analysis. Ammonium pyrrolidinedithiocarbanate (APDC), anthranilic acid and 8-hydroxyquinoline have been investigated as possible coprecipitating agents. The suitability of Bi³⁺, Fe³⁺, Ni²⁺ and Pb²⁺ ions as metal carriers has also been studied. It has been found that the above elements can be quantitatively coprecipitated with APDC in the presence of Bi³⁺ carrier at pH 4. The precision and accuracy of the method for all elements are found to be between ±2 and 10%. The enrichment factors are of the order of 10³. The detection limits are in the ppb range varying between 0.04 ng · ml^–1 for Co and V and 5 ng · ml^–1 for Zn. The method has been applied to tap and well waters, and river and lake water samples collected from Halifax County, Nova Scotia.