Neutralization dialysis

Neutralization dialysis is proposed to be suitable for water purification because weak acids (such as acetic acid, carbonate, bicarbonate ions), and weak bases (like amines, ammonia) easily permeate through the membranes.188 190 Soluble silicate compounds in water can be removed by this method. Also, desalination of protein solutions containing sodium chloride has been reported by using a spiral module, in which a cation exchange membrane, spacer and anion exchange membrane were wound alternately.191 

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Neutralization dialysis Separation of electrolyte and nonelectrolyte, desalination of water, etc. 

Diffusion dialysis Donnan dialysis Piezodialysis Neutralization dialysis Pervaporation Facilitated transport... 

Separation of electrolytes based on the difference in chemical potential across the ion exchange membrane can be classified into (i) diffusion dialysis, (ii) Donnan dialysis, (iii) neutralization dialysis and (iv) up-hill transport. The natural flux of electrolytes through the membrane is low compared with that in the presence of an electrochemical potential. 

Figure 6.34 Principle of neutralization dialysis. C Cation exchange membrane A anion exchange membrane.

Figure 6.35 Transport mechanism of formaldehyde through an anion exchange membrane by neutralization dialysis.

M. Igawa, H. Tanabe, T. Ida and F. Yamamoto, Separation of weak acids and bases by neutralization dialysis, Chem. Lett., 1993, 1591-1594. 

The successful of recovery of RNase A functional activity by a heat-induced AR method suggested the possibility of recovering RNase A immunoreactivity as well. The immunoreactivity of native RNase A and RNase A that was incubated at a concentration of 4 mg/mL in 10% neutral buffered formalin for 1 day and then freed of formaldehyde by dialysis against PBS was compared using capture enzyme-linked immunosorbent assay (ELISA). Selected fractions that... 

Lantagne and Velin [267] have reviewed the application of dialysis, electrodialysis and membrane cell electrolysis for the recovery of waste acids. Because of the new trends governed by environmental pressures, conventional treatment methods based on neutralization and disposal are being questioned. Membrane and electromembrane technologies are considered to be potential energy-efficient substitutes for conventional approaches. Paper mills will focus on the application of ion-exchange membranes namely dialysis, electrodialysis and membrane cell electrolysis for recovery of waste acids. 

BDE 17, 28, 47, 66, 85, 99, 100, 153, 154 183 Palm oil Palm oil Extraction by dialysis in hexane using a semi-permeable membrane. Purification thorugh multilayer column filled with neutral silica, silica modified with sulfuric acid (44%, w/w), and silica modified with KOH. Gas Chromatography (VF-5MS Factor Four, Varian) IT-MS 0.07-1.3 pg (instrumental limit of detection) [42]... 

Jack-bean meal is a rich and convenient source of a-D-manno-sidase,34 and the enzyme displays zinc-dependence in characteristic fashion.38 At pH values below neutrality, the enzyme is unstable unless a zinc salt is added, and the instability is particularly marked during dialysis or gel chromatography. In our first method of purification,38 the later stages were performed at pH 5 in the presence of 100 yM zinc sulfate. Table V gives a brief outline of the purification procedure. 

Allergic reactions to ESAs have been infrequent. There have been a small number of cases of pure red cell aplasia (PRCA) accompanied by neutralizing antibodies to erythropoietin. PRCA was most commonly seen in dialysis patients treated subcutaneously for a long period with a particular form of epoetin alfa (Eprex with a polysorbate 80 stabilizer rather than human serum albumin) that is not available in the USA. After regulatory agencies required that Eprex be administered intravenously rather than subcutaneously, the rate of ESA-associated PRCA diminished. However, rare cases have still been seen with all ESAs administered subcutaneously for long periods to patients with chronic kidney disease. 

In writing the equations for the three component system (solvent, solutes A and B) we have treated the analysis as if the solutes were neutral. When working with proteins or other macromolecules which can ionize, it will be assumed that the solutes A and B have each been dialyzed against the same buffer or solvent, that the working stock is made up from dialyzed solutions of A and B, and that dilutions (at constant /3) are made with the solvent (buffer) in dialysis equilibrium with the concentrated solutions of A and B. Then it will be assumed that this procedure allows us to use equations applicable to three component systems. This problem is discussed in great detail by Casassa and Eisenberg (39). 

One of the prospective pathways for the synthesis of HCP involves copolymerization of neutral monomers with a basic ionogenic one. This procedure was used for synthesis of copolymers of acrylonitrile and dimethylaminoethyl methacrylate used for production of dialysis membranes67). Prior to use, the membranes were quater-nized with HC1 and subsequently treated with heparin. The reported high stability of the heparin-polymer complex (the loss of heparin on washing the polymer with distilled water for 70 hours was less than 1 %) does not obviously ensure that the HCP will perform properly when contacted with solutions of proteins and blood. 

For crystallization, the RNase Nj fraction eluted from the CM-cellulose column or Sephadex G-75 column was concentrated by lyophilization and then dialyzed against distilled water at 4°. During dialysis, fine needle-shaped crystals were formed. The specific activity of the crystals was about 2200. The solubility of the crystals is small around neutrality and increases below pH 4.0. Thus, the crystals are usually dissolved in dilute acetic acid. 

Fio. 3. Sedimentation coefficient and molecular weight as functions of pH. (A) Sedimentation coefficients as a function of pH. (O) s°0 w values were determined for samples adjusted from neutral pH to each pH value. The concentrations were 72 mg/ml, except at pH 5 and pH 4, where they were 4j0 mg/ml in 0.01 Af tris-0.01 Af sodium acetate. (0) s°0 w values were determined for samples adjusted from neutral pH to the given pH. Concentrations were 0.62 mg/ml in 0.1 Af NaCl-0.01 Af tris-0.01 M sodium acetate. ( ) s° w values were determined for samples prepared at pH 2, then dialyzed at the appropriate pH. Concentrations were 0.62 mg/ml in 0.1 M NaCl-0.01 Af tris-0.01 M sodium acetate. (O) Determinations with Schlieren optics all other determinations were made with the use of ultraviolet optics with the photoelectric scanner. (B) Weight average molecular weight as a function of pH. (0) M values were determined for samples adjusted from neutral pH to each pH indicated, by dialysis, 0.62 mg/ml, in 0.1 M NaCl-0.01 M tris-0.01 M sodium acetate. (O) Mw values were determined for samples prepared at pH 2, then dialyzed at the appropriate pH, 0.62 mg/ml in 0.1 M NaCl-0.01 Af tris-0.01 Af sodium acetate. 

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