Potassium hydrogen phosphate, solution preparation

Cjg, Abs = 284.06 x The data presented in this paper is the drug release in a phosphate buffer solution. The buffer solution was prepared by dissolving potassium hydrogen phosphate (0.8wt.%, Wako Chemicals) and sodium dihydrogen-phosphate (1.5wt.%,Wako Chemicals) in pure water. 

To prepare the standard pH buffer solutions recommended by the National Bureau of Standards (U.S.), the indicated weights of the pure materials in Table 8.15 should be dissolved in water of specific conductivity not greater than 5 micromhos. The tartrate, phthalate, and phosphates can be dried for 2 h at 100°C before use. Potassium tetroxalate and calcium hydroxide need not be dried. Fresh-looking crystals of borax should be used. Before use, excess solid potassium hydrogen tartrate and calcium hydroxide must be removed. Buffer solutions pH 6 or above should be stored in plastic containers and should be protected from carbon doxide with soda-lime traps. The solutions should be replaced within 2 to 3 weeks, or sooner if formation of mold is noticed. A crystal of thymol may be added as a preservative. 

X)8 695 m potassium dihydmgen phosphate. 0.030 43 m disodium hydrogen phosphate. Prepare like Buffer 5 dissolve 1.179 g KH2PO4 and 4.30 g Na2HPOA in water to give 1L erf solution at 25°C. 

The System Lime and Phosphoric Acid —Solubility of Calcium Phosphates— Conditions of Formation of Basic and Acid Calcium Phosphates—Composition of Solutions Saturated with Calcium Hydrogen Phosphates—Equilibria between Solid Phases and Solutions at Various Temperatures—Changes during Neutralisation—The Acid Phosphates—Manufacture of Superphosphate—Retrogression—Treatment of Special Ores—Phosphoric Acid— Commercial Preparation and Extraction from Rook—The History and Technology of Superphosphate Manufacture—Mixed and Concentrated Phosphorio Fertilisers—Potassium Phosphates—Ammonium Phosphates. 

Potassium Chromate, KjCrOj, is usually prepared fi-om the dichromate vide infra) by neutralisation of the excess of CrOa above that necessary to form the normal salt, e.g. by potassium carbonate in aqueous solution by fusion of the dichromate with potassium nitrate or potassium carbonate, and extraction with water by interaction of potassium dichromate with ammonium chloride or sodium hydrogen phosphate. ... 

Heavy metal orthophosphates (M = Cr, Mn, Fe, Co, Ni, Zn, Hg, Pb, Ag) can be prepared in hydrated form by simple double decomposition involving aqueous solutions of an alkali hydrogen phosphate and the appropriate metal salt. Cobalt phosphate octahydrate, for example, is obtainable as a beautiful lavender-coloured precipitate from cobalt chloride and potassium dihydrogen phosphate. 

Preparation 24 g anhydrous disodium-hydrogen-phosphate (Na2HP04) and 46 g anhydrous potassium-dihydrogen-phosphate (KH2PO4) are dissolved in distilled water. To this, 100 cm 0.02 M EDTA solution and 0.020 g mercury(II) chloride (HgClj) are added and the volume filled up to 1000 cm. ... 

Prepare in 50 mM potassium phosphate buffer, pH 7.4, an anaerobic solution of a ruthenate chelate, here potassium chloro[hydrogen(ethylenedinitrilo)nithen-ate, and dilute this in the same anaerobic buffer CO a final concentration of 50 j,m of the complex (Solution A). 

---