Speciation of Trace Elements in Acidic PoreWaters from Waste Rock Dumps by Ultrafiltration andIon Exchange Combined with ICPMS and ICPOES

A speciation procedure developed on reactive acidicpore water samples from mining areas is presented.Methods with low consumption of solution are requiredthat allow rapid sample preparation to avoid equilibriumchanges as far as possible. The entire procedure includesonly three parallel separation steps. One aliquot is filteredthrough an 1 kd ultrafiltration membrane to separate traceelements adsorbed or complexed by colloids. One cationand one anion exchange are performed with two additionalaliquots to determine simple hydrated ions and smallinorganic complex ions. Commonly used procedures ofion exchange seem to be problematic. This new techniqueis based on a novel ion exchanger. Subsequently the threefractions obtained from the separation procedures and theoriginal pore water sample are analysed by ICPMS, ICPOES,ET-AAS, Flame-AAS, FES and IC to determine the concentrationsof the major ions and additionally up to 50 trace elements. Theinfluence of pH-values and several dissolved compounds iscontrolled in experiment series with synthetically preparedsolutions to reveal potential artifacts.