Crystals mother liquor

The total filtrates from the crystals (mother liquors plus washings) are made basic by addition of 2 molar ammoniacal ethanol in approximately equal volume and allowed to stand several days at room temperature when the mixture is filtered and taken to dryness and treated in the same manner as the residue from step 2 for a second crop of crystals. 

Finally, we note that all transfers to alcohol-water mixtures or additions of alcohol to crystal mother liquor involve changes in the proton activity of the solution. Care must be taken to ensure that the pH does not change too much, or the crystal may be disrupted. Worse still, the enzymatic activity may be abolished. Control of proton activity in mixed solvents is discussed in Section III,D. If dielectric effects are controlled and pH is properly adjusted, the microenvironment of a crystalline protein will correspond closely to that of aqueous solution at room temperature. Such correspondence is essential for temporal resolution of individual steps in a catalytic reaction. 

Visual examination of crystals using a light microscope does not indicate whether the crystals consist of only the protein or the protein-DNA complex. Therefore, the crystals are washed free of any uncrystallized DNA and protein several times with a solution containing the precipitant and any additives, etc. at the concentration and pH used for growing crystals (mother liquor). Finally, the crystals are separated from the mother liquor by microcentrifugation, dissolved in a suitable buffer, and analysed biochemically. The protein content is determined by SDS polyacrylamide gel electrophoresis, the protein concentration by BIO-RAD assay, and amino acid composition by mass-spectroscopy. The DNA can be detected by staining the gel with ethidium bromide or methylene blue (Jordan et al., 1985), whereas... 

Cleaning Up Empty the chromatography column onto a piece of aluminum foil in the hood. After the solvent has evaporated place alumina and sand in the nonhazardous waste container. Evaporate the crystallization mother liquors to dryness and place the residue in the hazardous waste container. 

Cleaning Up Combine the crystallization mother liquor with the filtrate from the reaction, dilute with water, neutralize with 10% hydrochloric acid, and flush down the drain. 

From the crystallization mother liquors, after concentration, neutralization, and re-extraction with ethylene dichloride, there can be obtained about... 

From the crystallization mother liquors, after concentration, neutralization, and re-extraction with ethylene dichloride, there can be obtained about 0.8 g. of amorphous d-isolysergic acid morpholide. This material can be isomerized to d-lysergic acid morpholide by the procedure disclosed by Smith and Timmis in J. Chem. Soc. 139, II, 1168 (1936). 

If crystal-mother liquor separation is difficult, a nonclassified fines desmiclion circuit can be con-... 

Table 14.3-1 Commercial Parex Operation with p-Diethylbenzer e. Separalion of p-Xylene from Crystallizer Mother Liquor.11...

Figure 6.12 Crystal Mounting The delicacy of crystals generated from biological macromolecule crystallisation requires that individual crystals for X-ray crystallography be mounted in a sealed capillary separated from crystal mother liquors by an air pocket. The capillary is mounted in the goniometer head of a four circle diffractometer (see Fig. 6.15).

Methoxysitsirikine (hervine) has been isolated from the crystallization mother liquors derived from herbaceine and herbaine (80a). 

A simple filtration test, using a deep Buchner funnel (>500mL capacity) and vacuum flask to measure the rate of filtrate production Figure 9.30d), is useful for assessing the ease or difficulty of the crystal-mother liquor separation step. The parabolic law of filtration (Carman, 1938) suggests that, for an incompressible cake, the volume of filtrate V collected over a period of time t is given by... 

Looking at a crystal layer with a microscope shows that it consists of crystals which are separated by grain boundaries (Fig. 8.2-14). Along these grain boundaries and also within the crystals, mother liquor can be included. Therefore, further decrease of the cleaning effect is obtained in real crystal layers compared to the thermodynamically possible. Wintermantel (1986) was able to show that this influence of the morphology of the crystals can be correlated to the dimensionless parameter... 

The solution described in the last column above goes to crystallization, where we choose a temperature of 10°C. The crystallizer mother liquor (curve G) therefore contains 33.5 g NaCl and 4.5 g Na2S04 per 100 g water. If no NaCl crystallizes here, we have... 

When a cyclone (not shown) is used to concentrate the Glauber s salt slurry, the overhead can be combined with the crystallizer mother liquor. Mother liquor at that point properly becomes a misnomer. The crystallizer process may have a number of sidestreams and recycles to improve the efficiency of the process, but these do not change the fundamental mode of operation which this example is meant to illustrate. 

The monohydrate process is more energy-efficient. Because of the low solubility of trona, the dissolving and clarification steps in the sesquicarbonate process both are at a high temperature. The solution is more corrosive. The major disadvantage of the monohydrate process is the contamination of the carbonate solution with organics and minerals such as silicates. This makes a purge of the crystallizer mother liquor necessary. Its size depends on the extent of contamination. 

Neutron diffraction data at low resolution (13 A) were recorded at Institut Laue Langevin (Grenoble). Four crystals (0.2 x 0.2 x 1 mm3) were transferred and soaked In crystallization mother liquor containing 0,33, 66,100 % D2O respectively. 

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