Pure Compounds from Petroleum

Ion Exchange as a Separations Method. VIII. Relative Elution Positions of Lanthanide and Actinide Elements with Lactic Acid Eluant at 87°

“…(3) with a fit of 0.009 is considerably better than the linear equation Cac/Cbu = 2.20(Cl,/Ceu) -0.236 (4) with a fit of 0.029.…”

“…The ion-exchange data are of interest in themselves and in relation to chromatographic separations. Consider the following exchange reaction of the alkaline earth cations, M + +, with the sodium form of the exchanger M + + + 2Ñü+^± M+++ 2Na+ (4) where the bar over the symbol represents the resin phase. The dependence of Ad(M) on concentration changes can be deduced from Donnan membrane or mass action considerations as was done previously.2 Under the experimental conditions in which [Na+] >> [M++] and [Na+] >> [M++] the variation of Ad(M) with ionic strength of the aqueous phase should, neglecting activity coefficients, in both the external solution and resin phases, vary inversely as the square of the Na+ concentration.…”

Coal chemistry. 8. Reactions of tetralin with coal and with some carbon-14-containing model compounds

“…p-Ethyltoluene has been described by Rossini. 24 We prepared it from p-tolualdehyde and methylmagnesium iodide to yield methyl-p-tolylcarbinol, which was reduced by zinc amalgam in aqueous HC1 to yield p-ethyltoluene. Purity was demonstrated by GC and NMR analyses.…”

Determination of Purity of Steroids: Solubility Analysis

“…Among the classical methods for determining purity are the freezing and melting curves, which have been used very successfully in studies of petroleum products (14)• However, such procedures are reliable only for compounds which are completely stable under the conditions of study. Melting point methods are frequently inapplicable in the determination of purity7 of steroids, as certain of these substances are heat labile and give decomposition ranges rather than equilibrium melting points (20).…”