Anew, highly sensitive and selective catalytic kinetic method (CKM) for determination of osmium (VIII) has been established based on its catalytic effect on the oxidation of thionine dye by hydrogen peroxide in alkaline medium. The reaction has been followed spectrophotometrically by measuring the decrease in the absorbance band of thionine at 600 nm. Under the optimum conditions, the proposed ...

Firstand second-order derivative spectrophotometric methods for the quantitative determination by converting menadione sodium bisulphite (MSB) to menadione (M ) with sodium carbonate were developed and validated in pharmaceutical preparation. The quantitative determination of MSB was carried out by using wavelengths 350 nm (for first-order; 1D) and 355 nm (for second-order; 2D) with the lineari...

A simple, precise economical and fast visible spectrophotometric method has been developed for the determination of Itopride hydrochloride in tablet dosage form. Developed is based on formation of extractable colored complex of drug with coloring agent mordant blue 3. A wavelength maximum was found to 471.0 nm. Linearity was observed 30-70 mg /mL. The proposed method describes the determination...

In this study, the reaction between Co(III)-EDTA and hypophosphite ion, catalyzed by Pd(II), was chosen as the indicator reaction. The inhibition kinetics of this catalytic reaction were investigated in the presence of iodide ion and the possibility of its analytical application was evaluated. Catalyzers other than PdCl2 (Pt, Au and Ni salts) were assayed for the indicator reaction and it was o...

A simple, rapid and sensitive method has been developed for determination of traces of silver(I) (0.2 - 13 ng mL(-1)) based on its catalytic effect on the oxidation of thionine by peroxodisulfate in the presence of 1 - 10 phenanthroline as an activator. The reaction is monitored spectrophotometrically by measuring the decrease in absorbance of thionine at 600 nm by the fixed time method. The de...

A simple, precise and accurate method is proposed for rapid determination of trace amounts of hydroxylamine based on the reaction of hydroxylamine with iodate in acidic media. The reaction of neutral red by the produced nitrite ion was used to monitor the reaction spectrophotometrically at 525 nm by a fixed time method. Hydroxylamine in the range of 0.0400-1.200 microg mL(-1) could be determine...

A simple, selective and sensitive kinetic method has been developed for the determination of trace amounts of iodide. This method is based on a catalytic effect of iodide on the reaction between Janus Green and bromate in acidic media. Trace amounts of iodide increase the rate of a reaction that is monitored spectrophotometrically at 618 nm by a fixed-time method at 30 s. Effective parameters o...

The kinetic properties and substrate specificity of two well-characterized peptidyl prolyl cis-trans isomerases (PPIases), cyclophilin and the FK-506 binding protein (FKBP), have been previously examined [Fischer, G., Bang, H., Berger, E., & Schellenberger, A. (1984) Biochim. Biophys. Acta 791, 87-97; Harrison, R.K., & Stein, R.L. (1990) Biochemistry 29, 1684-1689; Albers, M.W., Walsh, C.T., & ...

The H-point standard addition method was applied to kinetic data for simultaneous determination of citric and ascorbic acid or selective determination of ascorbic acid in presence of citric acid. The method is based on the difference in the rate of reaction of citric and ascorbic acid with copper(II)-ammonia complex. The linear dynamic ranges for the two analytes of citric and ascorbic acid are...

A simple and sensitive kinetic method is described for the determination of ketoprofen in pure form, pharmaceuticals and biological fluids. The method utilizes an oxidative- coupling reaction based upon oxidation of 3-methyl-2-benzo-thiazolinone hydrazone hydrochloride (MBTH) with Ce(IV) in presence of HCl, where an electrophilic intermediate (diazonium salt of the reagent) is produced, then co...