Micellar electrokinetic chromatographic analysis of thorium, uranium, copper, nickel, cobalt and iron in ore and fish samples

In this study an MEKC method has been developed and applied for the analysis of thorium and uranium from environmental samples. Copper, nickel, cobalt, and iron present in the matrix were analyzed concurrently. The method is based on pre-capillary chelation of analyte with bis(salicylaldehyde) ethylenediimine (H2SA2en) chelating agent. The analysis was completed within 4 min with uncoated fused silica capillary under the following optimized conditions: borate buffer 60 mM restraining 13 mM SDS (micellar medium) and 11.5% acetonitrile, pH 8, applied voltage 30 kV. The detection was carried out at 231 nm wavelength. Linear dynamic ranges were within 0.4-100 μg mL−1 and limits of detection (LOD) within 0.04-0.08 μg mL−1 of each element. The analysis of ore samples indicated thorium and uranium within 561-2501 μg g−1 and 25-911 μg g−1 with RSD 1.7-3.8% and 1.5-3.9% correspondingly. Thorium and uranium in fish samples were found below detection limit. The results of analysis of thorium, uranium, copper, nickel, cobalt and iron obtained by MEKC were comparable with that of supplier's specifications and AAS.