Determination of Mo(VI), Ru(III), Re(VII) and NO3 - in the solutions of nuclear fuel cycle by capillary electrophoresis

Abstract

Summary A method for simultaneous quantitative determination of Mo(VI), Re(VII), Ru(III) and NO3 - ions in aqueous solutions, using capillary zone electrophoresis (CZE) technique with direct UV detection, was developed. Electrophoretic mobility of Ru(III) ions in 0.1M NaHCO3 solution was determined as 6.0×10-8m2 V-1 s-1 at 25 °C. The best analytical characteristics of the developed method were achieved with a 100mM carbonate buffer solution containing 0.3mM TTAB, at a pH value of 9.8 and at an applied voltage of 10kV. Under these conditions, a linear relationship between the measured absorbance (λ=230nm) and the concentration of the species under study were observed in the range 5×10-6–10-3M for Mo(VI), 7×10-6–10-3M for Re(VII) and 10-5–-4M for Ru(III). The minimum detectable concentrations were determined as 4.1×10-6M for NO3 -, 5.2×10-6M for Mo(VI), 7.4×10-6M for Re(VII) and 1.0×10-5M for Ru(III). The accuracy of quantitative determination was estimated as 3%–5% for NO3 - and 5%–6% for Mo(VI), Re(VII) and Ru(III) ions. The presence of 0.06M NaNO3 (HNO3) and of 10-3M U(VI) in the sample affected neither the detection limits of the species under study nor the selectivity of the method.