this study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (v). the method is based upon the catalytic effect ofvanadium (v) on the oxidation of carminic acid by bromate in sulfuric acid media. the reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...

A sensitive and simultaneous spectrophotometric flow injection method for the determination of vanadium(IV) and vanadium(V) is proposed. The method is based on the effect of ligands such as 2,4,6-tris(2-pyridyl)-1,3,5-triazine (TPTZ) and diphosphate on the conditional redox potential of iron(III)/iron(II) system. A four-channel flow system is assembled. In this flow system, diluted hydrochloric...

This study describes a new simple, sensitive and selective catalytic kinetic spectrophotometricmethod for the determination of vanadium (V). The method is based upon the catalytic effect ofvanadium (V) on the oxidation of Carminic acid by bromate in sulfuric acid media. The reaction wasfollowed spectrophotometrically by measuring the decrease in absorbance at 490 nm and thedependence of sensiti...

Vanadium can be an important contaminant in groundwaters impacted by mining activities. In order to determine if microorganisms of the Geobacteraceae, the predominant dissimilatory metal reducers in many subsurface environments, were capable of reducing vanadium(V), Geobacter metallireducens was inoculated into a medium in which acetate was the electron donor and vanadium(V) was the sole electr...

Vanadium, V, is a redox-sensitive metal that in solution, under aerobic conditions, prevails as the oxyanion vanadate(V). There is little known regarding vanadium toxicity to soil biota, and the present study was set up to determine the toxicity of added vanadate to soil organisms and to investigate the relationship between toxicity and vanadium sorption in soils. Five soils with contrasting pr...

Interest in vanadium chemistry has increased since the recognition of the involvement of vanadium ions in many important biological systems.1 The distinctive preference of the vanadium ion for N/O donor atom types has prompted the synthesis and characterization of many model complexes containing N/O donor ligands, the spectroscopic properties and solution behavior of which have been investigate...

a simple and sensitive extractive- spectrophotometric method for thedeterrnination of trace amounts of vanadium(v) is reported. the method is based on the quantitative extraction of the anion complex of v(v) with 4-(2-pyridy1azo)-resorcinol with tetrabutylammonium perchlorate into chloroform, followed by spectrophotometric measurements at 554 nm. beer's law is obeyed over the concentration...

vanadium silicates such as v-al-analcime, v-analcime, v-magediite and v-zsm-11 were synthesized using vanadium pentoxide or vanadyl sulfates. vanadium silicates with analcime structure with and without aluminum (v-al-analcime, v-analcime) were prepared as pure phase by hydrothermal crystallization from a gel with molar composition of (1 sio2; 0.2 v2o5; 1 na2o; 0.034 al2o3; 35.7 h2o) and (1 sio2...

The reaction of the oxidovanadium(V) complexes with N,N-dimethylhydrazine was demonstrated to afford the corresponding vanadium(V) dimethylhydrazido complexes. The substituent at the 3-position of the tris(2-hydroxyphenyl)amine ligand was found to influence the electronic environment of the vanadium center. The crystal structure of the non-substituted vanadium(V) dimethylhydrazido complex exhib...

Some ascidians accumulate vanadium in vanadocytes, which are vanadium-containing blood cells, at high levels and with high selectivity. However, the mechanism and physiological significance of vanadium accumulation remain unknown. In this study, we isolated novel proteins with a striking homology to glutathione transferases (GSTs), designated AsGST-I and AsGST-II, from the digestive system of t...