Molybdenum phosphorus chlorides

Zinc, copper, chromium, manganese, and possibly selenium and molybdenum are the only trace elements that require supplementation during PN. Requirements for trace elements during organ failure are not clearly defined. Manganese and copper should be restricted or withheld in patients with cholestatic liver disease. Chromium, molybdenum, and selenium should be restricted or withheld in patients with renal failure. Sodium, potassium, calcium, magnesium, phosphorus, chloride, and acetate are necessary components of PN for maintenance of numerous cellular functions. 

Lead and silver calibration solutions do not contain other metals as the chloride salts. Also, sodium and potassium calibration solutions do not contain molybdenum, phosphorus, silicon, and chromium, which are used as the potassium and sodium salts). The acid concentration of the samples is adjusted to within 10% of the concentration of the calibration solutions. This procedure eflFectively minimizes solution uptake rate and nebulization eflSciency eflPects which have been reported (10,12,13). 

The decomposition products were separated by eluting with potassium chloride solution on a column packed with anion-exchange resin, Dowex 1x4 in chloride form. During the elution the concentration of potassium chloride in the eluent was increased exponentially. The phosphorus contents in effluent fractions were determined colorimetrically with a molybdenum(V)-molybdenum(VI) reagent (4J. 

The oxychloride MoO Clg is obtained when chlorides of molybdenum are heated in the air, and, among other compounds, when the dioxide, or a mixture of the trioxide with carbon, is heated in chlorine, or when molybdenum trioxide and phosphorus trichloride are heated together it is not formed, however, when a mixture of common salt, sulphuric acid, and molybdenum trioxide is heated cf. p. 28). A pale yellow amorphous substance, soluble in water and alcohol, it is easily sublimed, and is reduced on heating in hydrogen or carbon monoxide to the dioxide. 

If higher sensitivities are desired then the ammonium phosphomolybdate product may be reduced with stannous chloride or ascorbic acid in order to give soluble molybdenum blue [24]. Spectrophotometric determination of the blue absorbance at 885 nm gives a detection limit of 0.003 mg/L phosphate, stated as phosphorus (3 ppb in freshwater) or 0.0092 mg/L as expressed phosphate [24]. 

After extraction, in the filtered extract, phosphorus is estimated colorimetrically by adding ammonium molybdate and thereafter reducing the molybdenum-phosphate complex in acidic medium with a reducing agent for which stannous chloride is used. The intensity of the blue colour molybdenum blue is directly related to the quantity of orthophosphate ion and thus provides a measure for the concentration of P in test solution. The absorbance or transmittance is measured spectrophotometrically at 660 mp,. wavelength. 

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