Orthophosphate, reaction with sulfate

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). 

This enzyme [EC 2.7.7.5], also known as ADP sulfurylase, catalyzes the reaction of ADP with sulfate to produce orthophosphate and adenylylsulfate. 

Europeum generally is produced from two common rare earth minerals monazite, a rare earth-thorium orthophosphate, and bastnasite, a rare earth fluocarbonate. The ores are crushed and subjected to flotation. They are opened by sulfuric acid. Reaction with concentrated sulfuric acid at a temperature between 130 to 170°C converts thorium and the rare earths to their hydrous sulfates. The reaction is exothermic which raises the temperature to 250°C. The product sulfates are treated with cold water which dissolves the thorium and rare earth sulfates. The solution is then treated with sodium sulfate which precipitates rare earth elements by forming rare earth-sodium double salts. The precipitate is heated with sodium hydroxide to obtain rare earth hydrated oxides. Upon heating and drying, cerium hydrated oxide oxidizes to tetravalent ceric(lV) hydroxide. When the hydrated oxides are treated with hydrochloric acid or nitric acid, aU but Ce4+ salt dissolves in the acid. The insoluble Ce4+ salt is removed. 

Fig. 8-2. Simultaneous analysis of weak and strong inorganic acids. — Separator column IonPac AS4A eluent 0.0017 mol/L NaHC03 + 0.0018 mol/L Na2C03 flow rate 1 mL/min detection (A) suppressed conductivity, (b) photometry at 410 nm after post-column reaction with sodium molybdate injection volume 50 pL solute concentrations 3 ppm fluoride, 4 ppm chloride, 10 ppm nitrite and bromide, 20 ppm nitrate, 10 ppm orthophosphate, 25 ppm sulfate, and 27 ppm orthosilicate.

Fig. 9-116. Analysis of condensed phosphates in a detergent. - Separator column lonPac AS7 eluant 0.07 mol/L HNO3 flow rate 0.5 mL/min detection photometry at 330 nm after reaction with ferric nitrate injection 50 pL of a 0.1 % washing powder solution peaks (1) orthophosphate, (2) pyrophosphate, (3) sulfate, and (4) triphosphate.

A. The Reaction of Sodium Hydrogen Sulfate with Disodium Hydrogen Orthophosphate... 

Poni and CernStescu (47) have reported that a new compound with the formula, NasSPCj, which has an S-O-P linkage, can be prepared by fusion of an equimolar mixture of sodium hydrogen sulfate and disodium hydrogen orthophosphate. The investigation on the same reaction by Audrieth et al. (48) has revealed that the reaction proceeds according to... 

From a consideration of the above discussion it may be concluded that the main reaction of an equimolar mixture of sodium metaphosphate and disodium sulfate at a high temperature proceeds according to equation 8 and that any compound with S-O-P linkages, at least as a major component in the crystalline substances, is not formed by this reaction. A pattern of normal trisodium orthophosphate exhibits three characteristic peaks at spacings of 2.55, 2.70, and 4.25 A. The discrepancy between the spacings of the peaks due to normal trisodium orthophosphate and the unknown species discussed here remains as an unsolved problem. 

In 1999, Wagner et al. [61] developed another derivatization technique for the analysis of bromate, which can be directly combined with the US EPA Method 300.1 [62], In Part A, Method 300.1 describes the separation of the seven standard anions bromide, chloride, fluoride, nitrite, nitrate, orthophosphate, and sulfate, and in Part B the separation of bromate, bromide, chloride, and chlorite on an lonPac AS9-HC high-capacity anion exchanger. The technique developed by Wagner et al. is based on the reaction of bromate with o-dianisidine (ODA) in an acidic solution [63,64] with subsequent photometry of the reaction product at 540 nm. 

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