Three indirect methods for the quality control of olanzapine (OLP) in commercial formulations based on titrimetric and spectrophotometric techniques are described using N-bromosuccinimide (NBS) and two dyes, namely amaranth and janus green B as reagents. In titrimetry, a measured excess of NBS is added to an acidified solution of OLP and the unreacted NBS is determined iodometrically. Spectroph...

A method for sensitive and selective determination of silver based on the catalytic effect of silver(I) ion on the oxidation of Janus Green by peroxodisulfate is described. o-Phenanthroline is used as an activator. The rate of the decrease in absorbance of Janus Green (at 615 nm) is proportional to the concentration of silver in the range of 0.3-4.0 ng mL(-1) and 4.0-500.0 ng mL(-1). The theore...

A sensitive and selective kinetic-spectrophotometric method was developed for the determination of trace amounts of uric acid. The method is based on the inhibitory effect of uric acid on the oxidation of Janus Green by bromate in the presence of sulfuric acid. The reaction was followed spectrophotometrically by measuring the absorbance at 518 nm using the fixed-time method. Under optimum exper...