Determination of uranium, iron, copper, and nickel in rock and water samples by MEKC

A micellar electrokinetic capillary chromatographic (MEKC) procedure has been developed for the separation and determination of dioxouranium (VI), iron(III), copper(II), and nickel(II) using bis(salicylaldehyde)propylenediimine (H 2 SA 2 Pn) as chelating reagent with a total run time of <3 min. Sodium dodecyl sulphate (SDS) was used as micellar medium at pH 8.1 with sodium tetraborate buffer (0.1 M). Uncoated fused silica capillary with effective length 38.8 cm×75 μm id was used with an applied voltage of 30 kV and photo‐diode array detection at 228 nm. Linear calibrations were established within 0.045–1000 μg/mL of each element with detection limit within 15–122 ng/mL. The method was applied to the analysis of spring water and rock samples. The presence of uranium in rock and spring water samples was established within 1.58–1739.3 μg/g and 0.047–0.712 μg/mL with relative standard deviation within 0.9–2.1% and 1.3–2.6% respectively. Uranium ore and water samples were also assayed by the standard addition technique. Recovery of uranium was >98% with RSD up to 2.7%. Copper, nickel, and iron in their combined matrix were concurrently determined within RSD 0.6–3.6% ( n = 5) and the results obtained were compared with those of flame AAS.