Cerium acetate sulphate

The Swiss school of Karbeb and Schmid [20, 42, 44, 76, 77, 86, 88, 112— 115b, 144,168,169, 209,259—261] shows preference for the solvents chloroform, chloroform-methanol (50 +10) or benzene-ethyl acetate-diethylamine (70 + 20 + 10). The alkaloids are visualised by spraying with cerium(IV)-sulphate (Rgt. No. 37) or iodoplatinate reagent (No. 147) and then heating. Renneb [184] has been able to detect vobasine also by spraying with 2,6-dibromoquinonechloroimide (Rgt. No. 62). Schmid [88] cites values for 20 curare alkaloids he used chloroform-methanol (50 + 10) or benzene-ethyl acetate-diethylamine (70 + 20 + 10) as solvent. 

The articles of Farnsworth et al. [51, 53, 54] and of Svoboda [235] may be named amongst the older work using TLC. MoKBri et al. [133 to 136] and TrojInek and co-workers [141, 142, 243] have also engaged in such work. Neuss et al. [40] have carried out a notable investigation on the TLC of these alkaloids they employed silica gel 6 and alumina layers, testing 11 solvents, of which five proved satisfactory. The colour reaction with cerium(IV)-sulphate (Rgt. No. 34) was quoted for all the alkaloids. In two-dimensional TLC on an alumina layer, pure chloroform (first dimension) and chloroform-ethyl acetate (50 + 50) (second dimension) were used for development. 

In a recent paper, Moutarlier et al. [15] have claimed that the use of cerium salts in sol-gel-based corrosion protection is limited due to the high solubility of the cerium ions. In all of the papers cited here, the authors limited themselves to the use of cerium chloride or cerium nitrate. In order to examine the influence of alternative anions, in the present study, cerium sulphate, cerium acetate hydrate (cerium Ac) and cerium acetylacetonate (cerium Acac) have been compared to cerium nitrate and cerium chloride. Additionally, attempts were made to limit the solubility of cerium chloride and cerium nitrate with the addition of acetylacetone to form complexes of the cerium ions. Table 10.1 gives the solubilities of the cerium compounds examined in this study. 

The cerium compounds used for these experiments were cerium acetylacetonate (cerium Acac), cerium nitrate hexahydrate (cerium nitrate), cerium chloride heptahy-drate (cerium chloride), cerium acetate hydrate (cerium Ac) and cerium sulphate. Additionally, cerium nitrate and cerium chloride were dissolved in ethanol and mixed... 

A— 4 wt.% cerium nitrate —A— 4 wt.% cerium nitrate acac - t> 4 wt.% cerium chioride -->--4 wt.% cerium chioride acac 4 wt.% cerium sulphate — —4 wt.% cerium acetylacetonate —4 wt.% cerium acetate... 

It maj- also be separated from solutions of uranium salts bj the addition of a little cerium salt and precipitation with aqueous hydrofluoric acid, or with oxalic acid or bj adding a small quantity of thorium nitrate and precipitating with t-nitrobenzoic acid. It may also be absorbed bj- charcoal,iDasic ferric acetate, and by various oxides, sulphides, sulphates, and gelatinous silica. In the case of charcoal the uranium X is completely removed from a solution of a... 

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