Spectrophotometric Determination of Os(VIII) with Nitroso R Salt as Chromogenic Reagent
Abstract
Several methods have been reported for the spectrophotometric determination of osmium with various chromogenic reagents. Some of these reagents react slowly with osmium and the conditions for obtaining reproductibile colours are usually empirical.
In this context, a simple and sensitive spectrophotometric method for the determination of trace amounts of osmium(VIII) using disodium-1-nitroso-2-hydroxynaphthalene-3,6-disulphonate (Nitroso R salt) is described. The method is based on the formation of an Os–Nitroso R salt complex which exhibits two different colours as function of pH. Linear calibration graphs are obtained up to 60 μg/mL of the analyte at pH = 4.8. The stoichiometry of the complex is found to be 1: 4 by mole ratio method. The method is optimized and different analytical parameters were evaluated. For instance, the calculated values for the molar absorptivity are of 3.645.103 L/mol.cm (pH = 0; λ = 550 nm) and 1.695.103 L/mol.cm (pH = 4.8; λ = 510 nm), respectively. The proposed method should be valuable for the determination of osmium(VIII) with good accuracy and precision.
Downloads
References
[2]. S.C. Shome, S. Nandy, A. Guhathakurta, N.C. Ghosh, H.R. Das, P.K. Gangopadhyay - Spectrophotometric determination of ruthenium, rhenium, osmium and platinum with organic thiohydrazides, Mikrochim Acta 70(1978), 343-357.
[3]. A. Thimme Gowda, N.M. Made Gowda - Spectrophotometric determination of osmium with ethylisobutrazine hydrochloride, Microchimica Acta 88(1987), 351-357.
[4]. S. Dadfarnia, M. Shamsipur - Extraction–spectrophotometric determination of osmium using 4–(2- pyridylazo) resorcinol, Bull. Chem. Soc. Jpn. 64(1991), 3063-3066.
[5]. M.K. Deb, N. Mishra, K.S. Patel, R.K. Mishra - Sensitive spectrophotometric determination of osmium with pyrocatechol and hydroxyamide,Analyst 116(1991), 323-325.
[6]. S.S. Sawant - Sequential separation and spectrophotometric determination of osmium and platinum with 5–chloro–2–hydroxythiobenzhydrazide, Anal. Sci. 25(2009), 813-818.
[7]. J.L. Manzoori, M.H. Sorouraddin, M. Amjadi - Spectrophotometric determination of osmium based on its catalytic effect on the oxidation of carminic acid by hydrogen peroxide, Talanta 53(2000), 61-68.
[8]. Q.E. Cao, Z.Li, J. Wang, C.Li - Catalytic spectrophotometric determination of osmium based on oxidation of basic dyes, Chem. Anal.(Warsaw) 47(2002), 701-712.
[9]. B. Morelli - Allylthiourea as a reagent for the spectrophotometric determination of osmium, Analyst 111(1986), 1289-1292.
[10]. J. Seetharamappa, N. Motohashi, D. Kovala–Demertzi - Application of phenothiazine derivatives and other compounds for the determination of metals in various samples, Current Drug Targets 7(2006), 1107-1121.
[11]. A. Wasey, R.K. Bansal, B.K. Puri - Spectrophotometric determination of iridium(III) and osmium(VIII) with phenanthrenequinone monoxime after extraction into molten naphtalene, Microchimica Acta 82(1984), 211-220.
[12]. B. Joseph, S. John, M. Prajila, A. Joseph - Spectrophotometric determination of osmium(VIII) in trace amounts using ethylene thiourea(ETU) as chromogenic reagent, Indian Journal of Chemical Technology 18(2011), 113-117.
[13]. C. Paduraru - Ph. D. Thesis „Analitycal Chemistry of Platinum Metals” (2005).
[14]. V.N. Losev, Yu. V. Kudrina, A.K. Trofimchuk, P.N. Komozin - Features of the sorptive extraction of osmium in different states with silica gels chemically modified with mercapto and disulfide groups, J. Anal. Chem. 59(2004), 546-551.
