Analysis dialyzate

The solution was then dialyzed through a cellophane membrane against 4 iiters of water for 10 hours, with stirring. The dialysis was repeated 2 additional times, with fresh amounts of water. To the dialyzed solution there was added 2 mi of 1 N hydrochloric acid, whereupon polyestradiol phosphate was precipitated as a white bulky precipitate. This was centrifuged off and washed repeatedly with 0.1 N hydrochloric acid. Thereafter it was dried in a vacuum desiccator. The yield was 3 g of polyestradiol phosphate. The analysis shows 0.65% of water, 1.35% of pyridine and 9,3% of phosphorus (calculated on a dry sample). 

It must be pointed out that the atomic absorption system as used today, cannot accurately determine the calcium level of a solution. The reason for this is that results will vary depending upon the other elements present and the composition of the solution. Since it is impossible to duplicate every feature of the particular serum being analyzed, results have to be compared to standards which have been made up in serum dialysates. Such standards are available in the form of the Versatols where the calcium has been dialyzed out and then weighed back. This is distinct from substances such as Validate, which are used as controls and which values are re-sults of analysis. The variability of serum composition has significantly widened what is now considered the "normal range" for serum Ca assay when done by atomic absorption (37a). 

With a three-component system, such as a polymer in an aqueous salt solution, preferential adsorption of one component to the polymer can affect the analysis of light-scattering data.199 Such interactions can affect the SRI. Therefore, measurements of the SRI must be made at constant chemical potential. Constant chemical potential is achieved experimentally by dialyzing the solvent and polymer solution to equilibrium through a membrane permeable to the solvent but impermeable to the polymer.199... 

The third test of protein homogeneity, developments from which remain in common use, was that of electrophoresis. Arne Tiselius had been a research assistant in Svedberg s laboratory. From 1925 he pioneered the application of electrophoresis to the analysis and separation of protein mixtures, showing with dialyzed serum differences in mobility of the protein components and the presence of three classes of globulins, a, B, and y. 

Determination of amino acids in the analysis of dialyzed rat cerebrospinal fluid Chiral CEC separations of amino acids... 

If the eluted protein is used for amino acid analysis, the sample has to dialyze three times 1 h each against 100-fold of Soln. B. After lyophilization, the protein is analyzed. SDS, which is not dialyzable under the given conditions, does not influence the determination. 

Ciosek, P., Grabowska, I., Brzozka, Z., and Wroblewski, W. (2008). Analysis of dialyzate fluids with the use of a potentiometric electronic tongue. Microchim. Acta 163(1-2), 139-145. 

One unit of a-D-mannosidase liberates 1 fig of p-nitrophenol from 6 mM p-nitrophenyl a-D-mannoside in 1 hr at 37° and pH 5. Protein was determined by the method of Lowry and coworkers,5 with bovine albumin as the standard. Metal analysis was performed by atomic absorption spectrophotometry. The enzyme preparation was purified to stage 5 of the original procedure (see Table V) and dialyzed at pH 8 to remove the excess of Zn2+ finally, gel chromatography was conducted at the same pH. 

To prepare proteoliposomes, 7 mg egg yolk phosphatidylcholine, 1.16 pg cholesterol, 77.5 pg cholesteryl oleate and 10 pCi [3H]-cholesteryl oleate, all dissolved in chloroform are mixed. After evaporation of chloroform with nitrogen, the lipids are resolved in 400 pi ethanol. The ethanolic solution is injected into 5 ml of a vortex-ing buffer with 39mmol/l sodium phosphate, 0.01% EDTA, 2 mmol/1 NaN3, and 12 mmol/1 sodium cholate (pH 7.4) 3 mg apoA-I is added. The solution is subsequently dialyzed against a buffer with 39 mmol/1 sodium phosphate, 0.01 % EDTA, 2 mmol/1 NaN3, and 12 mmol/1 sodium cholate (pH 7.4) at 4°C. At the end the solution is filled up with analysis buffer containing 39 mmol/1 sodium phosphate,... 

The principal rubidium salts which would probably have been present in the sediment (chloride, sulfate, bicarbonate, etc.) are all soluble in water. As discussed later, the red clay was thoroughly dialyzed prior to use (including prior to analysis by emission spectroscopy). Any rubidium salts initially present in the clay samples would, therefore, have been removed by the dialyzing solution. Hence, it was assumed that the rubidium concentration given in Table I represented sorbed rubidium which had been in equilibrium with the rubidium in the original interstitial seawater. Then when calculating distribution coefficients from experimental data, the concentration given in Table I was used as the initial clay-phase rubidium concentration, rather than zero as used with most of the other species studied. 

It was felt that the presence of residual salts in the clay would complicate the analysis of experimental data. Therefore, in order to remove such salts prior to using the clay, the samples of sediment were dialyzed (using deionized water) until a twentyfold concentration of the dialyzing solution did not yield a precipitate upon addition of silver nitrate. (Also, no precipitate was observed upon concentration of the solution.) The solids were then dialyzed once more, vacuum dried, and stored in sealed containers in a desiccator until needed. (The preceding procedure may have resulted in some alteration of the sorption properties of the red clay, particularly with regard to the hydrous oxides. It is intended to assess the extent of such alteration, if any, during the course of future work.)... 

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). 

The use of HPLC for the analysis of bovine milk proteins was introduced by Diosady et al. (59), who compared SE-HPLC on two SynChropac GPC-100 columns in series and RP-HPLC on a lO-jUm-particle-sizc RP-8 column, both with UV detection, for the separation of dialyzed freeze-dried whey proteins. Column temperature was 40°C and 47°C, respectively. Samples were eluted with Tris-buffer pH 6 for SE-HPLC and a linear gradient of two solvents, i.e., 98% 0.5 M KH2P04, pH 2, and 98% isopropanol, each with 2% 2-methoxyethanol for RP-HPLC. They... 

In the microadaptation of this method, 50 pi of the sample is prediluted to 1.0 ml. This total volume is added to the sample cup. The analysis rate is reduced to twenty determinations per hour, which, along with the larger sample pick-up tube, results in the complete utilization of the diluted sample. Apparently the membrane area in a single dialyzer unit allows a sufficiently adequate amount of urea to transfer to the recipient stream to conduct the analysis. This compares with the need for additional dialyzing surface required in the microadaptation of the glucose method. 

It was seen that the two readily diffusible substances, glucose and urea, did not dialyze at equivalent rates and that protein binding of calcium had to be overcome to obtain a dialysis rate proportional to its concentration. The instrument usually provides a dialysis rate (and therefore an amount dialyzed) which is proportional to the concentration of the substance being tested. However, this proportionality would need to be checked for any test adapted to automatic analysis. It was also seen that dialysis was influenced by the presence of protein, salts, membrane charges, etc., in that dialysis rate from standards was not always identical with that from plasma or serum. To date these differences have been corrected for by a constant factor. 

Two grams of HSPAN was added to 500 ml of water, the pH was adjusted from 9 to 6.5 with dilute hydrochloric acid, and 0.1 ml of Thermamyl 60L enzyme solution (Novo Enzyme Corp.) was added. The resulting mixture was heated at 95°C for 21 hr, and the clear yellow solution was exhaustively dialyzed against distilled water. Freeze drying yielded 1.235 g of polymer, which contained only about 5% residual carbohydrate (by infrared analysis). The number average molecular weight of this polymer was 44,000, as determined in 0.15N sodium chloride solution on a Melabs Model CSM-2 membrane osmometer equipped with a B-19 membrane (Schleicher and Schuell Co.). 

Pre-Column Reactions. Some pre-column cleanups are as simple as the dilution shown in the analysis of a fermentation broth (Figure 5). The dialyzer is used here not in its usual way, but rather as a filter, thus insuring a particle-free stream for the loop of the injection valve. 

Plastic microdevices for high-throughput screening with MS detection were also prepared for detection of aflatoxins and barbiturates. These devices incorporated concentration techniques interfaced with electrospray ionization MS (ESI-MS) through capillaries [2], The microfluidic device for aflatoxin detection employed an affinity dialysis technique, in which a poly (vinylidene fluoride) (PVDF) membrane was incorporated in the microchip between two channels. Small molecules were dialyzed from the aflatoxin/antibody complexes, which were then analyzed by MS. A similar device was used for concentrating barbiturate/antibody complexes using an affinity ultrafiltration technique. A barbiturate solution was mixed with antibodies and then flowed into the device, where uncomplexed barbiturates were removed by filtration. The antibody complex was then dissociated and electrokinetically mobilized for MS analysis. In each case, the affinity preconcentration improved the sensitivity by at least one to two orders of magnitude over previously reported detection limits. 

For an analysis of the protein fraction, the shell is cleaned as described above. It is then dissolved in 6M HCl at 4 C to avoid hydrolyzing the peptide bonds. This solution is reduced to a small volume with the rotary evaporator at low temperature (< 50°C), is diluted I I with double-distilled water, and is dialyzed exhaustively against water. The dialysate is brought to dryness in the rotary evaporator and resuspended in 6M HCl. Hydrolysis and subsequent processing of the sample follows the procedures described above. 

Renkin used Equation 6.1 to estimate permeability coefficients for several solutes from flow and clearance measurements made on the Kolff-Brigham artificial kidney (Figure 6.1). This theoretical analysis seems reasonably consistent with the experimental results. In the Figure/ the dashed line indicates a flow limitation to transport because clearance can never exceed dialyzer blood floW/ a result that is obvious from inspection of Equation 6.1 (i.e./ is never less than 0). 

An analysis of relative dialysis clearance and dialyzer permeability coefficient-surface area products that was made for the closely related compounds procainamide (PA) and N-acetylprocainamide (NAPA) is summarized in Table 6.3. Dialyzer clearance measurements of PA (CLpa) and NAPA (CLmapa)... 

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