Concentration, viii

A mixture of 0.10 mol of freshly distilled 3-methyl-3-chloro-l-butyne (see Chapter VIII-3, Exp. 5) and 170 ml of dry diethyl ether was cooled to -100°C and 0.10 mol of butyllithium in about 70 ml of hexane was added at this temperature in 10 min. Five minutes later 0.10 mol of dimethyl disulfide was introduced within 1 min with cooling betv/een -100 and -90°C. The cooling bath vjas subsequently removed and the temperature was allowed to rise. Above -25°C the clear light--brown solution became turbid and later a white precipitate was formed. When the temperature had reached lO C, the reaction mixture was hydrolyzed by addition of 200 ml of water. The organic layer and one ethereal extract were dried over potassium carbonate and subsequently concentrated in a water-pump vacuum (bath... 

To a mixture of 0.15 mol of the acetylenic bis-ether (see Chapter VIII-6, Exp.l) and 100 ml of dry diethyl ether was added in 20 min with cooling between -40 and -50°C 3 solution of 0.30 mol of ethyllithium (note 1) in about 250 ml of diethyl ether (see Chapter II, Exp. 1). After stirring for an additional 15 min at -45°C the mixture was cautiously poured into 200 ml of ice-water and 50 g of crushed ice (note 2). After vigorous shaking the layers were separated and the aqueous layer was extracted twice with small portions of diethyl ether. The combined ethereal solutions were dried over magnesium sulfate. After concentration of the... 

A suspension of sodium amide in 500 ml of anhydrous liquid artmonia was prepared from 18 g of sodium (see Chapter II, Exp. 11). To the suspension was added in 10 min with swirling a mixture of 0.30 mol of 1-chloro-l-ethynylcyclohexane (see VIII-2, Exp. 27) and 50 ml of diethyl ether. The reaction was very vigorous and a thick suspension was formed. The greater part of the ammonia was evaporated by placing the flask in a water bath at 50°C. After addition of 500 ml of ice-water the product was extracted three times with diethyl ether. The ethereal extracts were dried over anhydrous KjCOj and subsequently concentrated in a water-pum vacuum. Distillation of the residue afforded the amine, b.p. 54°C/15 mmHg, n 1.4345, in 87% yield. 

Immunoaffinity chromatography utilizes the high specificity of antigen—antibody interactions to achieve a separation. The procedure typically involves the binding, to a soHd phase, of a mouse monoclonal antibody which reacts either directly with the protein to be purified or with a closely associated protein which itself binds the product protein. The former approach has been appHed in the preparation of Factor VIII (43) and Factor IX (61) concentrates. The latter method has been used in the preparation of Factor VIII (42) by immobilization of a monoclonal antibody to von WiHebrand factor [109319-16-6] (62), a protein to which Factor VIII binds noncovalenfly. Further purification is necessary downstream of the immunoaffinity step to remove... 

Fig. 6. Share of U.S. market occupied by human albumin/plasma protein fraction, (—) Factor VIII concentrate, (-) intravenous immunoglobulin...

Table 11. Properties of Factor VIII (Antihemophilic Factor) and Factor IX Concentrates...

Factors I, II, III, V, VII, VIII, IX, X, XI, XII, and XIII, Protein C, and Protein S are synthesized in the Hver. Factor III is present in many different organs throughout the body. Factor IV is the divalent cation calcium. The concentration of calcium required for normal function of the blood coagulation system is much less than required for normal physiologic function of many organs in the body, eg, myocardium. 

Scheme VIII applies also to a system that includes a reagent if the reagent concentration is much larger than...

Scheme VIII has the form of Scheme II, so the relaxation time is given by Eq. (4-15)—appjirently. However, there is a difference between these two schemes in that L in Scheme VIII is also a participant in an acid-base equilibrium. The proton transfer is much more rapid than is the complex formation, so the acid-base system is considered to be at equilibrium throughout the complex formation. The experiment can be carried out by setting the total ligand concentration comparable to the total metal ion concentration, so that the solution is not buffered. As the base form L of the ligand undergoes coordination, the acid-base equilibrium shifts, thus changing the pH. This pH shift is detected by incorporating an acid-base indicator in the solution.

At the start of the experiment, the CO concentration in the product gas was very low, < 0.01% (Table VIII). The unusually high value (0.71% ) at 186 hrs stream time is the result of an analytical error. At the end of the experiment, after 2307 hrs stream time, CO in the product gas had increased to 0.93% (dry basis), and total methane produced per pound of catalyst was 32 mscf. 

Applying the steady-state approximation to both [VI] and [VIII] one obtains (29) for the steady-state concentration of VI and (30) for the steady-state concentration of VIII, viz. 

In the systems with polystyrene derivatives VIII, IX and multi-armed cyclotriphosphazenes XI, XII the conductivity seems to be dependent on the relative concentrations of inter- and intra-molecular complexes (Table 17). 

In past years, treatment for patients with hemophilia A has consisted of administration of cryoprecipitates (enriched in factor VIII) prepared from individual donors or lyophilized factor VIII concentrates prepared from plasma pools of up to 5000 donors. It is now possible to prepare factor Vlll by recombinant DNA technology. Such preparations are free of contaminating viruses (eg, hepatitis A, B, G, or HlV-1) found in human plasma but are at present expensive their use may increase if cost of production decreases. 

Recalling the previous assertion that efficient fractionation requires liquid-liquid phase separation, we conclude that nitrobenzene and amyl acetate should be satisfactory solvents from which to fractionate polyethylene by successively lowering the temperature and that the better solvent xylene should be avoided for this purpose. The character of the phase diagram may, in fact, be used as a criterion of the efficacy of a given solvent for fractionation (see Chap. VIII, p. 344). If the curve representing the precipitation temperature plotted against concentration rises monotonically, crystalline separation is clearly indicated if it passes through a maximum at a low concentration, liquid-liquid separation is virtually assured, and the solvent may be assumed to be a satisfactory one to use for fractionation. 

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