Sodium batch equilibrations

The general procedure for the batch equilibration experiments was as follows. About 0.25 to 0.55 grams of clay and 45 to 70 ml of 0.68 N NaCl solution were added to a 125-ml polyethylene bottle, Next 2.5 ml of a 0.68 N NaCl solution, buffered with predetermined amounts of sodium bicarbonate and/or boric acid, were added, (in order to obtain data at low values of the solution pH, addition... 

The batch contact consisted of equilibrating stoichiometric quantities of waste and ion exchanger for 15 to 30 minutes. The solid product was then washed with water to remove most of the sodium ions. This step was necessary as high sodium content in... 

Prior to evaluation, each sieve was conditioned carefully in moist air (usually at 125°C) to control the water content of the sieve. Batch adsorptions were run then in which 10.0 grams of heart-cut, 2.5 grams of isooctane, and 5.0 grams of sieve were held at 100°C for 2 hours to ensure complete equilibration between the raflBnate and the adsorbate. This 100 °C temperature was chosen because runs at ambient temperature were considerably slower in reaching equilibrium. The unadsorbed (raffinate) fraction was then filtered olf, and the cooled sieve was washed with room temperature isooctane to remove the remainder of the unadsorbed fraction. The adsorbate was removed with refluxing benzene. The results of these evaluations are shown in Table I. Sodium-Y sieve... 

The value of Dy is determined by shaking or stirring a specified amount of solution to which the ion of interest, such as the radionuclide, had been added with a specified amount of ion-exchange medium. When the radionuclide distribution between solid and liquid phase reaches equilibrium, the concentration of the radionuclide in each phase is measured. The batch of ion-exchange medium must be saturated initially with the specified backing ion and the initial solution must contain the same ion at a specified concentration. For example, if the radionuclide is a cationic radionuclide such as and the system for comparison is a sodium salt, then the ion-exchange medium must be in the sodium form and the solution that contains must be at a specified sodium backing-ion concentration. The concentration of nonradioactive potassium ion must also be specified. Any other radionuclides from which the radionuclide of interest is to be separated must be equilibrated under identical conditions of known volume ratios, ionic concentration, temperature, and equilibration period. 

Analytical grade anion-exchange resin (Bio-Rad, AG 1-X4, 1(X)-2(X) mesh or 2CKM00 mesh) was converted from its original chloride form to the perchlorate form by repeated equilibration with concentrated sodium perchlorate solution, first batch-wise in a beaker and finally in a column, until the effluent from the column gave a negative test for chloride. The column was then washed with distilled water to remove excess electrolyte. 

Two batches of the human adrenocorticotropic concentrate, one 800 mg and the other 730 mg, representing material from almost 7,000 glands, were dissolved separately in 5 ml 0.012 M sodium succinate-0. 015 M acetic acid buffer. After centrifugation each clear supernatant solution was chromatographed on a 2 x 92 cm carboxymethyl cellulose column equilibrated with 0.012 M... 

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