A simple and convenient method of reducing monosaccharide assay is proposed. A Si(IV)-Mo(VI) solution (pH 4.9) was yellow due to the formation of the 11- and/or 12-molybdosilicate(VI) anions. By the addition of a reducing saccharide, glucosamine, the mixture turned to blue gradually, indicating that the Mo(VI) species was reduced by the saccharide to form a blue molybdosilicate anion. The molyb...

A very simple, ultra-sensitive and highly selective non-extractive spectrophotometric method for the determination of trace amount of molybdenum(VI) using 5,7-dibromo-8-hydroxyquinoline (DBHQ) has been developed. 5,7-Dibromo-8-hydroxyquinoline reacts in a slightly acidic solution (0.05 - 1.0 M H2SO4) with molybdenum(VI) to give a deep greenish-yellow chelate which has an absorption maximum at 4...

Two simple, sensitive and economical spectrophotometric methods were developed for the determination of nifedipine in pharmaceutical formulations. Method A is based on the reaction of the nitro group of the drug with potassium hydroxide in dimethyl sulphoxide (DMSO) medium to form a coloured product, which absorbs maximally at 430 nm. Method B uses oxidation of the drug with ammonium molybdate ...

Solid-phase spectrophotometry has been improved for the determination of the total and dissolved phosphate in water. The target phosphate-P at sub-µg dm(-3) to µg dm(-3) levels in a 20-cm(3) water sample was concentrated as the molybdenum blue species to 0.06 or 0.12 cm(3) using a Sephadex G-25 within 30 min, and gel beads were introduced to a 1.5-mm or 3-mm diameter flow cell having a 10-mm li...

One of the commonly used methods for the calorimetric determination of phosphorus is based upon the reduction of molybdic acid to molybdenum blue and subsequent estimation of the intensity of the blue color formed.. An excellent discussion of the molybdenum blue reaction and its limitations is given by Woods and Mellon (1). In using this reaction over a period of years the authors have been inc...

Understanding the process of the self-assembly of gigantic polyoxometalates and their subsequent molecular growth, by the addition of capping moieties onto the oxo-frameworks, is critical for the development of the designed assembly of complex high-nuclearity cluster species, yet such processes remain far from being understood. Herein we describe the molecular growth from {Mo150 } and {Mo120 Ce...