Sodium dihydrogenphosphate

Potassium dihydrogenpho rhate Magnesium dihydmxide Sodium dihydrogenphosphate Sodium amide Water... 

FIGURE 1.4 Dependencies of retention factors k on counterion (i.e., phosphate) concentration [X]. Experimental conditions Mobile phase, methanol-sodium dihydrogenphosphate buffer (50 50 v/v) (pHa 6.5 adjusted in the mixture with sodium hydroxide) flow rate, 1 mLmin temperature, 25°C CSP, 0-9-[3-(triethoxysilyl)propylcarbamoyl]-quinine bonded to silica [30] column dimension, 150 x 4 mm ID. 

Glycyrrhizin can also be determined by ion-pair chromatography (64,105). Matsunaga et al. (64) separated glycyrrhizin from saccharin on a reverse-phase column with ethanol 50 mM sodium dihydrogenphosphate (2 3, v/v) containing 20 mM cetyltrimethylammonium chloride, pH 3. 

In the dyeing processfor wool, a nonionic or weakly cationic leveling agent is added to the liquor, and the pH adjusted to 3-4 with formic or acetic acid. The process is started at 40°C, and after some time the pH is adjusted to 5-6 with sodium dihydrogenphosphate. Dyeing is conducted at boiling temperature for 1 h. To eliminate hydrolyzed dye, an aftertreatment is performed at 80°C with ammonia (pH 8.5-9.0). The last rinsing bath is weakly acidified. 

Fig. 10.3. Electrochromatograms exhibiting the effect of the length of the bare-silica segment on the separation of benzene and alkylbenzenes. Capillary, 100 pm i.d. with a 20 cm ODS segment and a variable-length bare-silica segment of (a), 0 cm (b), 6 cm and (c), 28 cm. Mobile phase, 1.25 mM sodium dihydrogenphosphate, pH 6.0, containing 75% (v/v) acetonitrile. Applied field strength, 625 V/cm. Detection, UV at 254 nm. Solutes 1, benzene 2, toluene 3, ethylbenzene 4, propylbenzene 5, butylbenzene 6, pentylbenzene. Reproduced with permission from Yang and El Rassi [12].

Fig. 10.27. CEC separation of Cinosulfuron and by-products. Column 335 (250) mm x 100 pm i.d. packed with Synchropak non-endcapped C8, 3 pm, Conditions mobile phase, acetonitrile-20 mtf sodium dihydrogenphosphate, pH 4.0 (60 40 v/v) separation voltage, 15 kV injection, 5 kV, 3s applied pressure, 8 bar on both sides sample, 2.4 mM cinosulfuron dissolved in mobile phase. Reproduced with permission from Rapp et al. [128].

In this system the weak acid is sodium dihydrogenphosphate (NaH2P04) and the weak base is disodium hydrogenphosphate (Na2HP04). The action of the buffer system is similar to that of the hydrogencarbonate system. 

Consists of a weak base and its conjugate acid provided as a salt Examples Ammonia (NH3) and ammonium chloride (NH4CI) sodium dihydrogenphosphate (NaH2P04) and sodium hydrogenphosphate (Na2HP04)... 

A mixture of sodium dihydrogenphosphate, Na+H2PO and disodium hydrogenphosphate, (Na+)2HP04, will function as a buffer and control the pH to a value of approximately 7.0. In this example, the species with the greater number of available hydrogen atoms functions as the acid,... 

For the analysis of ellipticine in biological samples an octadecyl stationary phase in combination with acetonitrile - 0.01 M sodium dihydrogenphosphate buffer has been used70. To ensure resolution between ellipticine and 9-hydroxyellipticine a ratio of 1 3 had to be used (Fig.8.5). In the case where only ellipticine is present, a ratio of 36 64 was used. 

System 11 Amine adsorption/ion suppression chromatography on Micropak AX-5 with UV monitoring (200 nm) at room temperature acetonitrile/water/0.25 M sodium dihydrogenphosphate (72 18 6, v/v/v) running time 21-24 min [283]. 

Aminated starches have been further converted. For example, dimethyl-aminoethyl starch could be converted into glycosides by alcoholysis,2442 phosphorylated with sodium dihydrogenphosphate, and oxidized with hydrogen peroxide to carboxyl derivatives.520 Additional information on this subject can be found in Section VII. 2-Hydroxypropyltrimethylammonium chloride starch has been crosslinked with epichlorohydrin.2443 In contrast to animation, which requires basic solutions, phosphorylation occurs at pH 6.2444... 

Anhydrous zirconium phosphate (P04/Zr = 2) and the dihydrate are prepared by adding 100 ml of 1 ilf zirconium oxychloride 8H20 dropwise to constantly stirred, refluxing phosphoric acid solution prepared by dissolving two moles of sodium dihydrogenphosphate H2O in 200 ml of 3 ilf HCl. The zirconium phosphate gel is refluxed in its mother liquor for 25 hours and then washed until free of chloride. When air-dried, the dihydrate or y phase was obtained when vacuum-dried over calcium sulfate, the anhydrous a phase was obtained 117). 

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