Methanol sodium chloride system

In the analysis of the effect on the calculated quantity of random errors in measured quantities it is unfortunate that the only model susceptible to an exact statistical treatment is the linear one (II). Here we have attempted to characterize the frequency distribution of the error in the calculated vapor composition by the standard methods and have not included a co-variance term for each pair of dependent variables (12). Our approach has given a satisfactory result for the methanol-water-sodium chloride system but it has not been tested on other systems and perhaps of more importance, it has not been possible, so far, to confirm the essential correctness of the method by an independent procedure. Work is currently being undertaken on this project. 

Search the DDE (free Explorer Version) for vapor-liquid equilibrium data for the system methanol-sodium chloride. Calculate the activity coefficient of methanol as function of salt concentration. 

Elution with salt pulses A multiple step elution is performed by the introduction of, for example, 5%, 10%, 25%, 50%, and 100% of 1.5 M sodium chloride in 19 mM phosphate buffer (pH 2.5) containing 5% methanol. Each step is for 10 min and run at 0.5 mL/min. This elution method compromises analytical system dimensionality, as the peak capacity of the ion-exchange chromatography (IEX) step is equal at most to the number of salt steps. However, in the second dimension only one or two columns are needed and there is no particular limitation in the second dimension separation time as peptides are eluted in portions in a controlled manner. However, the number of salt steps is limited by the total analysis time. In this case the multidimensional system is relatively simple. 

Direct conductivity measurements do not provide a satisfactory index of added water in milk. However, it has been reported (Rao et al. 1970) that measurement of conductivity in nonaqueous solvents can be useful in detecting adulteration. The conductivities of extracts using two different solvent systems were correlated with the percentage of added water in the original milk. One solvent system consisted of 10 ml acetone and 90 ml methanol plus 3 g sodium chloride, and the other contained 2.65 g formic acid in 100 ml acetone. 

In the calculation of total pressure and vapor composition from boiling point data using the indirect method, the greatest source of error lies in the liquid-phase composition. We have attempted to characterize the frequency distribution of the error in the calculated vapor composition by the standard statistical methods and this has given a satisfactory result for the methanol- vater system saturated with sodium chloride when the following estimates of the standard deviation were used x, 0.003 y, 0.006 T, 0.1° C and tt, 2 mm Hg. This work indicates that in the design of future experiments more data points are required and, for each variable, a reliable estimate of the standard deviation is highly desirable. 

In a previous evaluation of salt-saturated data, it was found (7) that the methanol-water system saturated with sodium chloride showed little or no average bias for the calculated vapor composition for both the T — x fit and the GE/RT — x fit, it passed the area test quite easily and showed satisfactory values of all sample derivations. Hence this system was chosen for error analysis. 

The physicochemical criteria approach to reverse osmosis separations Involving the surface excess free energy of solvation for ionized and nonlonized solutes has been demonstrated by this work to include nonaqueous solutions. The parameters and correlations presented in this work permit the prediction of reverse osmosis separations and permeation rates for different alkali metal halides for cellulose acetate OEastman E-398) membranes of different surface porosities from only a single set of experimental data for a sodium chloride-methanol reference feed solution system. 

Michelberger, Th., and Franck, E.U., (1990), Ternary systems water-alkane-sodium chloride and methanol-methane-sodium bromide to high pressures and temperatures, Ber. Bunsenges. Phys. Chem. 94, 1134-1143. 

In neonates up to 3 mo of age, Sephadex LH-20 chromatography is used before hydrolysis and derivatization. Four grams of Sephadex LH-20 in a glass column are allowed to swell in chloroform methanol (1 1 v/v saturated with sodium chloride). Then, the slurry is filled into a glass column. After Sep-pak C g extraction, the dried sample is taken up in 2 ml of the solvent system and applied on the column. The free and glucuronidated conjugates are eluted with 30 ml of the solvent system and the steroid sulfates are eluted with a further 50 ml of methanol. Both fractions are then dried, reconstituted in 4 ml of 0.1 M acetate buffer, hydrolyzed and derivatized as described above. 

The initiation systems of the ligands with Cu(II) salt in aqueous. solution were adjusted to various pH values with sodium hydroxide, while keeping the ionic strength of the reaction system constant by adding sodium chloride. Polymerization was carried out in sealed tubes in the usual manner. Vinyl monomer (2.0 mL) and carbon tetrachloride (1.0 mL) were added to 4.0 mL of aqueous Cu(II)-chelate solution. The tubes were degased and thermo-stated at 60°C for 3 h. The polymer was precipitated by pouring the solution into a large excess of methanol and then dried in vacuum. 

Metal halide salts other than sodium iodide have been used sparsely to prepare halodeoxy sugars from sulfonate esters. Lithium chloride (107) and lithium bromide (33) have found limited application. Potassium fluoride (dihydrate) in absolute methanol has been used (51, 52) to introduce fluorine atoms in terminal positions of various D-glucose derivatives. The reaction is conducted in sealed tube systems and requires... 

General Considerations. The following chemicals were commercially available and used as received 3,3,3-Triphenylpropionic acid (Acros), 1.0 M LiAlH4 in tetrahydrofuran (THF) (Aldrich), pyridinium dichromate (Acros), 2,6 di-tert-butylpyridine (Acros), dichlorodimethylsilane (Acros), tetraethyl orthosilicate (Aldrich), 3-aminopropyltrimethoxy silane (Aldrich), hexamethyldisilazane (Aldrich), tetrakis (diethylamino) titanium (Aldrich), trimethyl silyl chloride (Aldrich), terephthaloyl chloride (Acros), anhydrous toluene (Acros), and n-butyllithium in hexanes (Aldrich). Anhydrous ether, anhydrous THF, anhydrous dichloromethane, and anhydrous hexanes were obtained from a packed bed solvent purification system utilizing columns of copper oxide catalyst and alumina (ether, hexanes) or dual alumina columns (tetrahydrofuran, dichloromethane) (9). Tetramethylcyclopentadiene (Aldrich) was distilled over sodium metal prior to use. p-Aminophenyltrimethoxysilane (Gelest) was purified by recrystallization from methanol. Anhydrous methanol (Acros) was... 

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