Preparation Sodium phosphate

Orthophosphate salts are generally prepared by the partial or total neutralization of orthophosphoric acid. Phase equiUbrium diagrams are particularly usehil in identifying conditions for the preparation of particular phosphate salts. The solution properties of orthophosphate salts of monovalent cations are distincdy different from those of the polyvalent cations, the latter exhibiting incongment solubiUty in most cases. The commercial phosphates include alkah metal, alkaline-earth, heavy metal, mixed metal, and ammonium salts of phosphoric acid. Sodium phosphates are the most important, followed by calcium, ammonium, and potassium salts. 

Starch sodium phosphate monoesters [11120-02-8] are prepared by heating mixtures of 10% moisture starch and sodium monohydrogen and dihydrogen phosphates or sodium tripolyphosphate. Starch phosphate monoesters are used primarily in foods, such as pudding starches and with oH-in-water emulsions. 

FIGURE 7.10 Dependence of the resolution on the sample volume. A preparative Superformance column 1000-200 (bed volume 20 liters) packed with Fractogel END BioSEC (S) (bed height 63 cm) was loaded with 60 ml (top) and 300 ml of a mixture of bovine serum albumin (5 mg/ml), ovalbumin (5 mg/ml), and cytochrome c (3 mg/ml) (bottom) (20 m/VI sodium phosphate buffer, 0.3 M NaCI, pH 7.2 flow rate 100 ml/min corresponding to 19 cm/hr). When the sample volume is 300 ml the separation efficiency for BSA and ovalbumin is similar. Thus the column can be loaded with larger sample volumes, resulting in reasonable separations. 

FIGURE 7.13 Preparative separation of various proteins on Fractogel EMD BioSEC (S). The length of the column was 1000 mm and the inner diameter 100 mm. The flow rate was 6.2 ml/min with 20 sodium phosphate buffer (pH 7.2) containing 0.3 M NaCI as the eluent. The injected standard proteins can be used to create a calibration curve. 

FIGURE 7.18 Preparative separation of abnegates from monomer of human IgG on a Fractogel EMD BioSEC (S) column (1000 X 50 mm column volume 1.88 liter). Five milliliters of a sample consisting of IgG (10 mg/ml) was applied at a flow rate of 10 ml/min (21.4 cm/hr) to remove aggregates (eluent 20 mM sodium phosphate, 0.1 At sodium chloride, pH 7.2). 

This is a crystalline product of insulin and an alkaline protein where the protein/insulin ratio is called the isophane ratio. This product gives a delayed and uniform insulin action with a reduction in the number of insulin doses necessary per day. Such a preparation may be made as follows 1.6 g of zinc-insulin crystals containing 0.4% of zinc are dissolved in 400 ml of water, with the aid of 25 ml of 0.1 N hydrochloric acid. To this are added aqueous solutions of 3 ml of tricresol, 7.6 g of sodium chloride, and sufficient sodium phosphate buffer that the final concentration is As molar and the pH is 6.9. 

Purification of photoprotein. The dialyzed photoprotein solution was centrifuged to remove precipitates, and then subjected to fractional precipitation by ammonium sulfate, taking a fraction precipitated between 30% and 50% saturation. The protein precipitate was dissolved in 50 ml of 10 mM sodium phosphate, pH 6.0, containing 0.1 mM oxine ( pH 6.0 buffer ), dialyzed against the same buffer, and the dialyzed solution was adsorbed on a column of DEAE-cellulose (2.5 x 13 cm) prepared with the pH 6.0 buffer. The elution was done by a stepwise increase of NaCl concentration. The photoprotein was eluted at 0.2-0.25 M NaCl and a cloudy substance (cofactor 1) was eluted at about 0.5 M NaCl. The photoprotein fraction was further purified on a column of Sephadex G-200 or Ultrogel AcA 34 (1.6 x 80 cm) using the pH 6.0 buffer that contained 0.5 M NaCl. 

Over 50% is used to make glass. Other uses include the preparation of chemicals (such as sodium silicate and sodium phosphate), soaps and detergents, in the pulp and paper industry, and in water treatment. Substantial amounts are exported. 

Preparations of PEG-modified proteins. A. SC-PEG (1 g, 0.2 mmol) was added to a stirred solution of Bovine Serum Albumin (BSA) (100 mg, 1.5 x 10 6 mol) in 0.1 M sodium phosphate, pH 7.8 (60 mL). Sodium hydroxide (0.5 N) was used to maintain pH 7.8 for 30 min. The excess of free PEG was removed by diafiltration using 50 mM phosphate buffered saline. Approximately 30 amino groups of the native protein were modified as determined by trinitrobenzenesulfonate (TNBS) assay (28). The same degree of modification was obtained when the experiment was repeated under identical conditions using SS-PEG instead of SC-PEG. 

Figure 14.3 SDS-PAGE of recovery of lysozyme in the presence of BME. Lane M, molecular weight marker lane 1, FFPE lysozyme tissue surrogate lane 2, a 75 mg/mL solution of lysozyme heat coagulated for 10 min at 100°C in 10 mM sodium phosphate buffer, pH 7.4. Both preparations were resuspended in 20mM Tris-HCl, pH 4, with 2% SDS and 0.5 M BME, and heated at 100°C for 20min followed by a cycle of heating at 60°C for 2h. For more detail, see Reference 25.

Prepare a set of standards by dissolving cysteine in 0.1M sodium phosphate, pH 8.0, at an initial concentration of 2mM (3.5mg/ml) and serially diluting this solution (1 1) with reaction buffer down to at least 0.125 mM. This will produce five solutions of cysteine for generating a standard curve. If a more dilute concentration range is required, continue to serially dilute until a set of standards in the desired range is obtained. 

Prepare the protein to be modified in a non-amine-containing buffer at a slightly basic pH (i.e., avoid Tris or imidazole). The use of 0.1 M sodium phosphate, 0.15M NaCl, pH 7.2 works well for NHS ester reactions. The concentration of the protein in the reaction buffer may vary from pg/ml to mg/ml, but highly dilute solutions will result in less efficient modification yields. A protein concentration from 1 to 10 mg/ml works well in this reaction. 

Prepare a 200 pi solution of amine-containing QDs at a concentration of 2.5 pM in 50mM sodium phosphate, pH 7.4 (reaction buffer). This represents 0.5nmole of QD in 200 pi buffer. 

Dissolve chloramine-T (Sigma) in 50 mM sodium phosphate, pH 7.5 (reaction buffer) at a concentration of 100 pg per 25-50 pi of buffer. Prepare fresh. 

Prepare liposomes containing PE by any desired method. For instance, the common recipe mentioned in Section 1 (this chapter) that involves mixing PC cholesterol PG PE in a molar ratio of 8 10 1 1 may be used. Thoroughly emulsify the liposome construction to obtain a good population of SUVs. The final liposome suspension should be in 20mM sodium phosphate, 0.15M NaCl, pH 7.2. Adjust the concentration to about 5 mg lipid/ml buffer. 

Prepare a liposome suspension, containing PE, at a total-lipid concentration of 5mg/ml in 0.1M sodium phosphate, 0.15M NaCl, pH 6.8. Maintain all lipid-containing solutions under an inert gas atmosphere. Degas all buffers and bubble them with nitrogen or argon prior to use. 

Prepare a 5mg/ml liposome suspension containing a mixture of PC cholesterol PG PDP-PE in molar ratios of 8 10 1 1. The emulsification may be done by any established method (Section 1, this chapter). Suspend the vesicles in 50mM sodium phosphate, 0.15 M NaCl, 10 mM ethylenediamine triacetic acid EDTA, pH 7.2. 

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