Mixture Gregory

Papaverine, C20H21O4N. This alkaloid, first obtained by Merck, occurs in the mixture precipitated by ammonia from the mother liquors of opium extract from which morphine and codeine have been separated in Gregory s process, and methods for its isolation from this mixture have been published by Hesse and others. The alkaloid may be purified by conversion into the acid oxalate, B. H2C2O4, m.p. 196° or 201-5-202°, which is nearly insoluble in alcohol. 

What we have covered in this chapter barely scratches the surface of a vast area of applications of colloidal phenomena in chemical and materials processing industries and in environmental and other operations. There are many fundamental, as well as practical, problems in the above topics (especially ones involving polymers, polyelectrolytes, and polymer-colloid and polymer-surfactant mixtures) that are currently areas of active research in engineering, chemistry, physics, and biology. Some of the references cited at the end of this chapter contain good reviews of topics that are extensions of what we have covered in this chapter (see, e.g., Elimelech et al. 1995, Hirtzel and Rajagopalan 1985, Israelachvili 1991, Gregory 1989, and O Melia 1990). 

Figure 19.12. Batch parametric processing of solid-liquid interactions such as adsorption or ion exchange. The bottom reservoir and the bed interstices are filled with the initial concentration before pumping is started, (a) Arrangement of adsorbent bed and upper and lower reservoirs for batch separation, (b) Synchronization of temperature levels and directions of flow (positive upward), (c) Experimental separation of a toluene and n-hcptane liquid mixture with silica gel adsorbent using a batch parametric pump. (Reprinted from Wilhelm, 1968, with permission of the American Chemical Society), (d) Effect of cycle time t on reservoir concentrations of a closed system for an NaCl-H20 solution with an ion retardation resin adsorbent. The column is initially at equilibrium with 0.05M NaCl at 25°C and a = 0.8. The system operates at 5° and 55°C. [Sweed and Gregory, AIChE J. 17, 171 (1971)J.

Codeine may be isolated from opium by the Gregory process [9], in which the concentrated aqueous opium extract is treated with a concentrated solution of calcium chloride, when calcium meconate, lactate, and sulphate are precipitated and removed, when the filtrate on concentration deposits the Gregory salt , a mixture of the hydrochlorides of morphine and codeine. This is purified, dissolved in water, and the morphine precipitated by ammonia, when the codeine remains in solution from which it is extracted by benzene, or the solution concentrated to the point at which a mixture of codeine hydrochloride and ammonium chloride separates. Other procedures for the isolation of codeine are available [7, 8, 10-22 inc.], critical summaries of which are given by Kanewskaja [23] and Barbier [24], Codeine may be separated from neopine (see Chap. VII) through the sulphate [25] and from morphine by chromatography [26-29]. Most of the codeine used commercially is prepared by the methylation of morphine (see below). 

COMPOUND POWDER OF RHUBARB. Synonym.—Gregory s Powder, or Gregory s Mixture. Take of—... 

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