Application of silylation to soaps, alcohols and amines in aqueous solutions

Abstract

Gas chromatographic analysis of many surfactants has been limited due to tailing and adsorption of the analyte on the stationary phase of the column by polar groups such as hydroxyl and amine functionalities. Silylation of these surfactants reduces these unfavorable interactions by replacement of the active hydrogen with a silyl group Si-(CHah. Although silylation generally is avoided in aqueous solutions, some surfactants have been silylated successfully in aqueous solutions. These include fatty acids and their hydroxamine soaps, fatty and other alcohols, fatty amines, and some inorganic acids. Quantitative results have been confirmed by stoichiometric, gas chromatographic and infrared data.

Liquid-liquid equilibria for the oleic acid-.beta.-sitosterol-water system at elevated temperatures and pressures

“…During this procedure Az was found to be relatively insensitive to changes in k,", NO Ak, was chosen as the sole criterion to be minimized. The use of Ak, as the minimization criterion has been reported by other workers (Correa et al, 1987;Zhang and Hill, 1991).…”

“…The amount of /3-sitosterol and its by-products in the samples was determined with a silylation technique that we have developed on the basis of the work of two earlier workers. Valdez et al (1986) developed a method for the silylation of fatty acids in aqueous solutions. Marks (1988) demonstrated that samples of soybean oil deodorizer distillate could be derivatized by silylation and analyzed by GC without previous saponification or separation of the neutral and acid fractions; however, his method is not applicable to systems containing water.…”