Determination of trace amounts of mercury(II) in water samples using a novel kinetic catalytic ligand substitution reaction of hexacyanoruthenate(II)

A simple, sensitive. selective and rapid kinetic catalytic method has been developed For the determination of Hg(II) tons at micro-level. This method is based oil the catalytic effect of Hg(II) ion oil the rate of substitution of cyanide in hexacyanoruthenate(II) with nitroso-R-salt (NRS) in aqueous medium and provides good accuracy and precision. The concentration of Hg(II) catalyst varied from 40 to 100 x 10(-6) M and the progress of reaction was followed spectrophotometrically at 525 nm (lambda(max) of purple-red complex [Ru(CN)(5)NRS](3-). epsilon = 3.1 x 10(3) M-1 s(-1)) under the optimized reaction conditions. 8.75 x 10(-5) M [Ru(CN)(6)(4-)]. 3.50 x 10(-4) M [nitroso-R-salt], pH 7.00 +/- 0.02. ionic strength, I = 0.1 M (KCl), temp 45.0 +/- 0.1 C The linear calibration curves. i.e calibration equations between the absorbance at fixed times (t = 15, 20 and 25 min) versus concentration of Hg(II) tons were established under the optimized experimental conditions The detection limit was found to be 1 0 x 10(-7) M of Hg(II). The effect of various foreign tons oil the proposed method has also been studied and discussed. The method has been applied to the determination of mercury(II) in aqueous solutions (C) 2009 Elsevier B.V. All rights reserved.