Application of ruthenium catalyzed oxidation of [tris(2-aminoethyl)amine] in trace determination of ruthenium in environmental water samples.

The ruthenium catalyzed oxidation of tris(2-aminoethyl)amine (TREN) by hexacyanoferrate(III) has been utilized for the development of a new and sensitive catalytic kinetic method (CKM) for the determination of ruthenium(III). The reaction was followed spectrophotometrically by the decrease in absorbance at 420 nm (lambda(max) of [Fe(CN)6]3-). The CKM developed utilizes fixed time procedure under optimum reaction conditions where the change in absorbance (DeltaAt) versus ruthenium(III) concentrations is plotted. The calibration curve recommended for the method is linear in the concentration range 10.11-252.67 ng ml(-1) with very good accuracy and reproducibility and a maximum error 2.20%. The detection limits of the method for ruthenium(III) corresponding to 10, 15 and 20 min are 8.02, 5.03 and 3.15 ng ml(-1), respectively. The ruthenium(III) has also been determined in the presence of several other interfering and non-interfering cations and anions and no foreign ions interfered in the determination of ruthenium(III) up to five-fold higher concentration of the foreign ions tested. The method is highly sensitive, selective and stable. It has successfully been applied for the determination of trace ruthenium(III) in some synthetic and environmental water samples. A review of most of the published catalytic kinetic and some other important methods for the determination of ruthenium has also been presented.