Chromatographic separation of platinum group metals from simulated high level liquid waste using macroporous silica-based adsorbents.
To separate platinum group metals (PGMs) from high level liquid waste, three novel macroporous silica-based adsorbents, namely, (Crea+Dodec)/SiO2-P, (Crea+TOA)/SiO2-P and (MOTDGA+TOA)/SiO2-P, were synthesized by introducing extractants Crea (N',N'-di-n-hexyl-thiodiglycolamide), TOA (Tri-n-octylamine), MOTDGA (N,N'-dimethyl-N,N'-di-n-octyl-thiodiglycolamide) along with theirs modifier, Dodec (n-dodecyl alcohol), into 50μm diameter SiO2-P particles by impregnation. Chromatographic separation of PGMs from simulated high level liquid waste was investigated by column method. It was found that 100% of Pd(II) and Re(VII) could be eluted out from simulate HLLW in 3.0M HNO3 solution using three adsorbents. For Ru(III) and Rh(III), high temperature has distinct effect on the adsorption rate and a further study for Ru(III) and Rh(III) is necessary to separate them from HLLW completely. In all six column experiments, a relatively satisfactory chromatographic separation operating for PGMs from simulated HLLW was obtained using (Crea+TOA)/SiO2-P adsorbent packed column at 323K.
Solvent extraction of rhodium chloride from aqueous solutions and its separation from palladium and platinum
Abstract The extraction of Rh chlorocomplexes with trioctylamine (TOA) or with Aliquat 336 (diluted with toluene) and its subsequent separation from Pd and Pt was studied. Species distribution calculations showed that the predominant species of Rh–Cl present in 1 M HCl is Rh(H 2 O)Cl 5 2− . Spectrophotometric measurements of Rh–chloride in the organic phase showed that Rh(H 2 O)Cl 5 2− is being extracted and slowly converted into a dimer, Rh 2 Cl 9 3− . Stripping is carried out with concentrated HCl. It is difficult to separate Rh chlorides from Pd and Pt by solvent extraction, and a gel-chromatographic method is therefore proposed in order to solve this problem.
Cholesterol synthesis from acetate in the diabetic liver.
Brady and Gurin (1) recently compared the ability of liver slices prepaped from both normal and diabetic rats to incorporate added acetate into cholesterol. They drew the conclusion that the conversion of acetate to cholesterol in the diabetic liver is “apparently unimpaired, although this process may be inhibited when diabetes is sufficiently prolonged and severe.” In view of our interest in the relation of cholesterol synthesis to arteriosclerosis, the development of which is generally regarded as being accelerated in diabetes (2), we have reinvestigated cholesterol synthesis from acetate in diabetes. A definite increase in cholesterol formation in the diabetic liver is demonstrated here. It is further shown that, as a result of insulin injections in a diabetic rat, slices subsequently prepared from its liver have a reduced capacity to synthesize cholesterol.