Potassium dihydrogen orthophosphate

The method may be standardised, if desired, with pure potassium dihydrogen-orthophosphate (see below) sufficient 1 1 hydrochloric acid must be present to prevent precipitation of quinoline molybdate the molybdophosphate complex is readily formed at a concentration of 20 mL of concentrated hydrochloric acid per 100 mL of solution especially when warm, and precipitation of the quinoline salt should take place slowly from boiling solution. A blank determination should always be made it is mostly due to silica. 

Phosphorus stock standard solution, 1000 pg P O mh (436 pg P mM) -dissolve 1.9173 g potassium dihydrogen orthophosphate, previously dried for 1 h at 105°C, in water. Transfer with beaker washings to a 1-1 volumetric flask, make up to the mark and mix. 

Potassium dihydrogen orthophosphate Sodium hydroxide solution, 1 M... 

Potassium stock standard solution, 1000 pg K mb - dry potassium dihydrogen orthophosphate (KH2PO4) for 2 h at 105°C, then allow to cool in a desiccator. Weigh 2.889 g into a 100-ml beaker, add sufficient water to dissolve, and transfer to a 1-1 volumetric flask with beaker washings make up to the mark with water and mix. 

Sodium hydride (50%, 85 mg, 1.77 mmol) was washed with dry ether (x 3) under nitrogen and suspended in dry THF (8 mL). To this suspension a solution of the hemiacetals 11 (0.52 g, 1.31 mmol) in dry THF (6 mL) was added during 5 min. The reaction was exothermic and a white gelatinous precipitate formed. After 45 min, the mixture was cooled to 0°C, quenched with cold aqueous potassium dihydrogen orthophosphate (1 M, 40 mL) and extracted with chloroform (3 x 20 mL). The combined extracts were dried (NajSO,), filtered through a pad of silica, and the filtrate was concentrated. Flash chromatography (Merck Kieselgel 60, 230-400 mesh diethyl ether-hexane, 2 1, v/v) afforded compound 12 (260 mg, 73%) as a syrup that crystallized at 5°C mp 44°-46°C, [a]D —88.3° (c 0.7, CHClj). 

Method. To 0.8 ml of the tissue extract are added 0.35 ml of water and 0.1 ml of a solution of DNS-C1 (100 mg/ml in acetone). The reaction mixture is then saturated with sodium carbonate. After reaction overnight at room temperature, 3 ml of acetone are added with shaking. The acetone phase is removed from the salts which are again washed with 3 ml of acetone. The combined extracts are neutralized with 0.15 ml of 0.066 M potassium dihydrogen orthophosphate and are then evaporated in a stream of air. The... 

Polymicro Technologies uncoated fused-silica capillary 75 cm x 75 pm Distance to detector 50 cm 0.05 M sodium deoxycholate, 0.01 M potassium dihydrogen-orthophosphate, 0.01 M sodium borate, pH 8.6 20 kV 27°C Commercial low joule soft drinks, cordials, tomato sauce, marmalade jam, powder sweeteners (Internal standard dehydroacetic acid) 220 nm 80... 

The pH of the reaction medium is initially 4. In order that the pH may be maintained between 4 and 5, methyl red is added in equal concentrations to each of the three solutions any change in pH is then detected by comparison with the color of a standard solution. If necessary, the pH of the reaction medium is adjusted by adding potassium dihydrogen orthophosphate. 

Mobile Phase Dissolve 0.504 g of potassium dihydrogen orthophosphate in 370 mL of water and adjust the pH to 3 with orthophosphoric acid. To this, add 80 mL of acetonitrile and 550 mL of methanol. The mobile phase is eluted at a flow rate of 1.3 mL/min. 

Disodium hydrogen phthalate-sodium dihydrogen orthophosphate Dipotassium hydrogen phthalate-potassium dihydrogen orthophosphate Potassium dihydrogen orthophosphate-sodium hydroxide Borate buffer, phosphate buffer... 

Synonyms E340 monopotassium phosphate potassium acid phosphate potassium biphosphate potassium dihydrogen orthophosphate. 

Phosphate-buffered saline (PBS) 120 mM sodium chloride, 11.5 mM Sodium dihydrogen orthophosphate, 31.3 mM potassium dihydrogen orthophosphate, pH 7.4-7.6. 

Dry potassium dihydrogen orthophosphate (grade specified for analysis) at 105 °C for 2 hours. Cool in a desiccator. Weigh 4.3938 g into a beaker, dissolve it in deionised water and transfer it to a 1 litre volumetric flask. Make up to the mark with water, stopper and mix well. 

Potassium Dihydrogen Orthophosphate Solution (c). Molecular weight of KH2P04 is 136.086, atomic weight of P is 30.9738. 

Numerous other reversed-phase methods exist for diltiazem hydrochloride tablets. One such method uses a Waters pBondapak C18 HPLC column (10 pm particle size, 300 mm x 3.9 mm I.D.). The separation is achieved at ambient temperature with a mobile phase of 40% (v/v) acetonitrile in 0.05M aqueous potassium dihydrogen orthophosphate at a flow rate of 2 mL/minute. Detection is achieved using UV absorbance at 254 nm. Ethanol is the extraction solvent resulting in a final concentration of the sample of 0.30 mg/mL and 20 pL is injected onto the column (63). Another similar chromatographic method is available for diltiazem hydrochloride in tablets (64). 

Partisil 10 mm ODS 3 column mobile phase - Potassium dihydrogen orthophosphate, tetra-butyl ammonium hydrogen sulphate, CH3OH, HCl,... 

KP03)3-II was first prepared by Grunze and co-workers (24). When potassium dihydrogen orthophosphate is treated with a mixed solution of acetic acid and diacetyl oxide (acetic anhydride) at 90°C. for 24 hr., almost all of it is converted into crystalline potassium trimetaphosphate (KP03)3-II. 

Fig. n.9.8. Separation of an anthracyclin mixture. Chromatographic conditions column, pBondapak C-18 mobile phase, 28% acetonitrile in aqueous potassium dihydrogen orthophosphate (8 g/1) acidified with citric acid to pH 3.0 flow rate, 5 ml/min temperature, 60 °C detection, UV at 254 nm. Peaks A, doxorubicin B, 13-dihydro-daunorubicin C, adriamycinone D, daunorubicin E, 13-dihydrodaunomycinone F, daunomycinone G, 14-bromodaunorubicin H, 14-bromodaunorubicin, 13-methyl-acetal. Reproduced from Alemanni et al. (1982), with permission. 

Potassium dihydrogen orthophosphate Potassium dihydrogen phosphate. See Potassium phosphate... 

Synonyms MKP Monopotassium orthophosphate Monopotassium phosphate Phosphoric acid monopotassium salt Potassium acid phosphate Potassium biphosphate Potassium dihydrogen orthophosphate Potassium dihydrogen phosphate Potassium diphosphate Potassium orthophosphate Potassium phosphate monobasic Potassium phosphate primary... 

Long-chain potassium polyphosphate, (KP03) , can be prepared simply by heating potassium dihydrogen orthophosphate when repeated condensation takes place to give a continuous chain of tetrahe-dra (5.142). Potassium polyphosphate can also be prepared by reaction (5.143) in which the heat of combustion of white phosphorus is used to assist the condensation of the PO4 tetrahedra as they are formed in embryo. 

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