Comparison of separation/preconcentration methods for toxic metal ion speciation with ICP-OES detection

CHED 205

Bethany Klinger and Dr. Yuan Mei-Ratliff. Department of Chemistry, Western Connecticut State University, 181 White Street, Danbury, CT 06810
The search for better (accurate, sensitive, versatile, fast and simple) methods for toxic metal detection is an on-going research focus for environmental analytical chemistry. The goal of this research project is to compare two sample pretreatment methods for chromium speciation. The first is based on a simple, selective precipitation and extraction method to separate Cr(III) from Cr(VI) ions prior to detection by an ICP-OES instrument. The second method uses a Chelex 100-equivqlent ion-exchange resin to selectively sequester Cr(III) ions for pre-concentration and detection. The latter technique will also be evaluated regarding its ability to simultaneously pre-concentrate Pb and Cd ions under the same condition used for sequestering Cr(III) ions. Results obtained from using both methods to analyze cement and clay samples will be compared.