Speciation of Trace Elements in Acidic Pore Waters from Waste Rock Dumps by Ultrafiltration and Ion Exchange Combined with ICPMS and ICPOES

摘要

A speciation procedure developed on reactive acidic pore water samples from mining areas is presented. Methods with low consumption of solution are required that allow rapid sample preparation to avoid equilibrium changes as far as possible. The entire procedure includes only three parallel separation steps. One aliquot is filtered through an 1 kd ultrafiltration membrane to separate trace elements adsorbed or complexed by colloids. One cation and one anion exchange are performed with two additional aliquots to determine simple hydrated ions and small inorganic complex ions. Commonly used procedures of ion exchange seem to be problematic. This new technique is based on a novel ion exchanger. Subsequently the three fractions obtained from the separation procedures and the original pore water sample are analysed by ICPMS, ICPOES, ET-AAS, Flame-AAS, FES and IC to determine the concentrations of the major ions and additionally up to 50 trace elements. The influence of pH-values and several dissolved compounds is controlled in experiment series with synthetically prepared solutions to reveal potential artifacts.