Resin Dowex

The residue is leached to give cesium sulfate solution, which can be converted to cesium chloride by ion exchange on Dowex 50 resin and elution with 10% HCl, treatment using ammonia or lime, to precipitate the alurninum, or by solvent extraction, followed by purification at neutral pH using hydrogen peroxide or ammonia. 

Dowex-50 resin Dow Chemical Co., available from J. T. Baker Chemical Co. 1,5-Cyclooctadiene A, MCB... 

In 1952 Carsten (Cl) developed a method, which allowed him to isolate and characterize several lower peptides contained in normal and pathological urine. According to this procedure, urine was desalted on the Amberlite IR-100 column and the adsorbed substances washed out with 2 M ammonia solution. The eluate was then passed through the column of Amberlite IRA-400. This column retained the ampholytes and rejected the weak bases. The former were recovered by elution with 1 M hydrochloric acid and the eluate was subsequently fractionated on Dowex 50 resin with 2M and later 4M hydrochloric acid as the eluents. By applying two-dimensional paper chromatography to further analysis of... 

These values differ from those in Table II, in that the rates are extrapolated back to sero time and do not necessarily represent the overall rate for the reaction nor do they represent anomerization. Rate constants are first order, given with time (in hours) and common logarithms. Reaction conditions Dowex-50 resin and methanol at 65c. 

The example cited in the patent used a mixed bed of Amberlite IRA 400 and Dowex 50 resins, and on an ammonium carbonate-sodium chloride exchange cycle reported a reduction of the sodium chloride content of the brine from 0.6A to 0.2A in one stage (0.6A is approximately the value of total dissolved salts in sea water). 

Figure 7. Radioactivity scan of an electrophoretogram of a NaB[3H]i reduced hydrolysate of mannose-6-phosphate (top) and a mannose-6-phosphate containing yeast phosphomannan (37) (bottom. The procedure is described in the text. The compounds migrating more rapidly than mannitol-6-phosphate are derived from decomposition of the Dowex-50 resin used to catalyze the hydrolysis. The migration of authentic mannitol and mannitol phosphate were determined by direct reduction of mannose and mannose-6-phosphate, respectively.

The hydroxide ppt. Is dissolved In dll. BCIO (0-5 M) and the mixture of radioactivities absorbed on a small amount of ammonium form Dowex-50 resin (spherical fines). 

The Au foil Is quickly dissolved In aqua regia and the Au extracted with ethyl acetate for 1 min. The aqueous phase is then eluted through a Dowex-1 anion resin column (2 zmn diameter, 1 cm long) with 6 M HC1 to complete the removal of Au end other impurities. The dropB. containing the actinide fraction are evaporated and the activity is then eluted through a Dowex-50 resin cation column with 0.4 M soln. of ammonium Q -hydroxy-isobutyrate, which is adjusted to pH 4.0 with HH4OH to separate the various actinide elements from each other, (Mv-Fm-E-Cf)... 

IRP-64 resin, IRC-58 resin, DOWEX 50 resin, Amberlife IR 120 resin. Nation resin used solvents-. DCM, EtOAc, toluene, dioxane, THF, acetone used adjuvants-. PhSMe, Et3SiH, m-cresol, HjO... 

Lanthanide Perchlorates. Stock solutions, approximately 0.3M, were prepared as described previously (5). The solutions were standardized by passing aliquots through a column of H -form Dowex-50 resin and titrating the liberated acid with standard sodium hydroxide. 

To prevent during the denitration step the formation of precipitates on which Pu and Am were partially and irreversibly adsorbed, denitration and oxalate precipitation were carried out in a single step by addition of the waste solution to the formic and oxalic acid mixture, the latter acid acting as a metal complexant during the denitration step. By experimental tests performed on simulated HAW according to this modified process scheme, separation yields of about 99.5% for Pu and 99.8% for Am were measured. A further reduction of the actinide content was reached by flowing the clarified HAW solution through a Dowex 50 resin column. The oxalate precipitation experiments on fully active HAW solutions have practically been completed. The results obtained from five runs (Table IV) confirmed the previous results obtained on simulated solutions. 

In these experiments the calcium distribution ratio between the Dowex 50 resin and the solution was established to be about ten by using the corresponding amounts of exchanger and CaCL salt. With such a distribution ratio, the isotopic fractionation effect is almost completely shifted into the solution, whereas the initial isotope ratio is present in the resin phase (see Chap. 2,4). Under this condition and under... 

For other basic amino acids, when the copper salt of the acetyl amino acid does not precipitate out, the product is desalted by absorbing on Dowex 50 resin which is then eluted with 3 N ammonium hydroxide. 

Phosphate. Because of interference by uranium in the usual magnesium ammonium orthophosphate procedure,5 uranium is first removed by a cation-exchange procedure. A column (2.5 by 36 cm.) of 50 to 75 cc. of Dowex-50 resin is washed with 200 ml. of Z N hydrochloric acid and then 200 ml. of water at flow rates of 2 to 3 ml./min. An acidic solution of the product, containing 100 to 150 mg. of orthophosphate, is passed through the column at a rate of 1 ml./min. The column is washed with water until the washings are neutral to litmus, and phosphate is determined in the combined eluate and washings by the usual gravimetric procedure.6 Uranium can be eluted from the... 

Dowex-50 resin) 2.4. The chromatographic and electrophoretic properties of the synthetic sugar were identical with those of pneumosamine hydrochloride, and the infrared spectrum (Nujol mull) of the synthetic sugar was consistent with the proposed structure. This evidence established that the sugar was enantiomorphous with pneumosamine hydrochloride. 

J. Chem. Soc. 1961, 1204 from sodium heparinate demineralized with Dowex 50 resin Brit. pat. 863,235 (1961 to UCLAF). 

The variation of the equilibria in the system Dowex 50 resin-Ca-Mg-Na is shown in Figure 9. The two divalent-monovalent exchanges are concentration-dependent. The divalent-divalent exchange is not. 

Neill and Higgins determined distribution coefficients for Pu(HI) and Pu(IV) for several resins in sulfuric acid solutions. Their results-are shown in Table IV-28. They used Dowex-50 resin to demonstrate a process for recovering Pu from sulfuric acid decladding solutions which contain stainless steel. The Pu is normally trivalent in dilute sulfuric acid solutions, and is adsorbed from 0,5 M acid, scrubbed with 0.5 M sulfuric acid, washed with water to remove sulfate, and eluted with 6 N HNOg. The product Pu solution contained 5% of the original stainless steel materials, primarily iron and chromium. 

Sequential group separations using a niimber of different com-plexlng agents in conjunction. with Dowex-50 resin has also been described by Blaedel, Olsen and Buchanan (B9). In this scheme lead Is removed from the resin with 2 per cent citric acid at pH 3.0 along with sixteen other elements. The notable separations appear to be from copper, zinc, cadmium, strontium barium and thallium which adsorb on the resin In this medium. 

Dowex 50" resin, saturated with nitric acid 6M Atomic Energy L 85 130 — — <0.0001 <0.0001 ... 

Fig. 13.1 Elution of homologous trivalent actinides and lanthanides from a Dowex 50 resin column at ZTC with a-hydroxyisobutyrate as eluant. The broken curve for element 103 (Lr) is a prediction.

The elution profile of praseodymium chloride (PrCIs) by a citrate buffer at pH = 3 from a Dowex 50 resin column (originally studied by Mayer and Tompkins (1947)) can be described by equation (7.1.102a) (Lightfoot etal. (1962) have described it in detail) in the presence of cerium (CeCIs) the sorption equilibria are linear and noninterfering. 

The later chemical work of Silva et was done with the Berkeley 65 s, 261 isotope, and this longer half-life enabled a rapid cation-exchange operation to be undertaken. The material was loaded on to Dowex 50 resin and eluted with ammonium a-hydroxyisobutyrate. Despite complications caused by the daughter No having a very similar alpha spectrum to Rf, it was concluded that Rf eluted in much the same fraction as Hf and Zr tracers, in contrast to actinide tracers which were not eluted in these conditions. 

Its shape and magnitude are similar to that shown for the Zeoharb-225-HNO system In figure 74. Ishlmorl and Okuno have found that Increasing amounts Of methanol In nitric acid solution (0.18h) Increase the distribution coefficient of uranium for Dowex-50 resin. 

Ishlmorl and Okuno have Investigated a number of cation exchange systems other than those already noted. Some of their results, D versus sodium sulfate, sodium acetate, and oxalic. acid concentration, are Illustrated In figure 76. The adsorption of uranium by Dowex-50 from solutions of hydroxylamlne was found to be pH dependent. As the pH of the solution was Increased, a sharp decrease In D was observed between pH 5 and 6. Uranyl Ion was not adsorbed by Dowex-50 resin from carbonate solution. 

Dowex-50 resin, HR form, 250-500 mesh, settling rate approxlmatelsr 0.5 am/mln. 

---