Vanadous fluoride

Olsnes S, Carvajal E, Sandvig K (1986) Interactions between diphtheria toxin entry and anion transport in Vero cells. III. Effect on toxin binding and anion transport of tumor-promoting phorbol esters, vanadate, fluoride and salicylate. J Biol Chem 261 1562-1569. 

Phosphate, arsenate, and vanadate interfere. Borate, fluoride, and large amounts of aluminium, calcium, magnesium, and the alkali metals have no effect in the determination, but large amounts of iron (> 5 per cent) appear to produce slightly low results. 

The most general method for the simultaneous analysis of oxyanions by gas chromatography is the formation of trimethylsilyl derivatives. Trimethylsilyl derivatives of silicate, carbonate, oxalate, borate, phosphite, phosphate, orthophosphate, arsenite, arsenate, sulfate and vanadate, usually as their ammonium salts, are readily prepared by reaction with BSTFA-TMCS (99 1). Fluoride can be derivatized in aqueous solution with triethylchlorosilane and the triethylfluorosilane formed extracted into an immiscible organic solvent for analysis by gas chromatography [685). 

RIPA lysis buffer (without vanadate and sodium fluoride inhibitor as they inhibit phosphatase activity)... 

Colorimetric Methods are used only for the estimation of very small percentages of vanadium, e.g. in vanadium steels and alloys. The most important depend on the intensity of the reddish-brown colour produced by the action of hydrogen peroxide on an acid vanadate solution.3 If chromium is present, an equal amount must be introduced into the standard vanadium solution under the same conditions of temperature, acid concentration, etc. Phosphoric acid is added to destroy any yellow colour due to ferric iron, and either hydrofluoric acid or ammonium fluoride to destroy any colour produced by titanium.4 A colorimetric method for the simultaneous estimation of small quantities of titanium and vanadium has also been worked out.5 Other colorimetric processes are based on (a) the formation of a yellow to black coloration, due to aniline black, in the presence of aniline hydrochloride and potassium chlorate or other oxidising agent,6 and (b) the orange coloration finally produced when an acid solution of a vanadate is brought into contact with strychnine sulphate.7... 

The complex with ADP and aluminium fluoride is thought to resemble the early ADP.Pi state immediately after hydrolysis, whereas the complex with ADP and vanadate may represent a late state in which the phosphate (mimicked by vanadate) has moved quite a long distance (15 A) from the active center to the surface of the motor domain. There it is fixed by two hydrogen bonds to the solvent exposed tips of the switch-1 loop region (L9) at one side and the switch-2 loop (Lll) at the other side. 

Werber MM, Peyser YM, Muhlrad A. 1992. Characterization of stable beryllium fluoride, aluminum fluoride, and vanadate containing myosin subfragment 1-Nucleotide complexes. Biochemistry 31 7190-7197. 

Chromates, vanadates, and cerium salts give colour reactions with the reagent and should therefore be absent. Iron salts give a yellow colour with hydrogen peroxide, but this is eliminated by the addition of syrupy phosphoric acid. Fluorides bleach the colour (stable [TiF6]2 ions are formed), and large amounts of nitrates, chlorides, bromides, and acetates as well as coloured ions... 

Vanadium (V, at. mass 50.94) occurs in the V, IV, III, and II oxidation states, vanadium(V) compounds being the most stable. In alkaline medium, the colourless vanadate VOs ions exist, whereas in strongly aeidic media, the yellow V02 cations are present. Within the intermediate pH range polymerized orange-yellow anionic forms occur. Vanadium(V) forms heteropoly acids with P(V), Mo(VI), and W(VI), and also peroxide complexes. Vanadium(IV) occurs as the blue vanadyl ion V02", stable in acid solutions and readily oxidized to vanadium(V) in alkaline solution. The VO cation is amphoteric. At pH 4, V0(0H)2 precipitates and at pH 9 it dissolves. Vanadium(IV) forms fluoride-, oxalate-, and... 

Since disturbed acid phosphatase activity has been associated with pathological conditions, the research has focused on the development of diagnostic methods for detection of activity as a marker for the onset of the disease, and in some extent to the development of inhibitors rather than activators to treat those conditions in which the increase in enzyme activity has a direct effect on the evolution of the disease. In particular, only the development of bisphospho-nate derivatives as inhibitors for tartrate-resistant acid phosphatase found their way to the market for treatment of osteoporosis [41], Typical inhibition of phosphatase activity includes anionic species such as L-(+)-tartrate, phosphate, vanadate, molybdate, and fluoride and neutral molecules such as formaldehyde. Vanadate ion,, is a competitive unspecific inhibitor for acid phosphatases by forming transition state analogs. Other oxoanions such as molybdate and tungstate also show inhibitory effects on... 

Gin s electrolytic method for ferrovanadium1 uses vanadic acid dissolved in a bath of fused iron fluoride and calcium carbide. The anode is a mixture of vanadic acid and retort carbon, and the cathode is fused steel. (2) A French process uses vanadic acid dissolved in calcium fluovanadate, and a current of 0.7 ampere per square centimeter of anode surface. (3) An American process electrolyzes a solution of vanadic acid in molten ferrosilicon. (4) Another American process passes an electric current through a charge made up of vanadium oxide and the calculated amounts of iron and carbon. 

Fusion with sodium carbonate, sodium peroxide, or sodium hydroxide likewise produces soluble sodium tungstate, molybdate, vanadate, etc. The caustic fusion method is adaptable to ores containing phosphates, fluorides, or titanium. The melt is extracted with water and on acidification tungstic acid is precipitated. Fusion methods are commonly used in large scale operations. 

VANADIUM (7440-62-2) V The finely divided material reacts with air, water, acids, alcohols may release flammable hydrogen gas and chemically basic materials. A reducing agent. Violent reaction with strong oxidizers, bromine trifluoride, chlorine, lithium, nitryl fluoride nitric, hydrofluoric, or concentrated sulfuric acids. May react with halogenated hydrocarbons, forming other reactive and possibly explosive materials. It reacts with chlorine at 356°F/180°C, forming vanadium tetrachloride. Forms water-soluble vanadates in alkalis. 

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