SIMPLE GAS-CHROMATOGRAPHIC METHOD FOR THE ASSAY OF SALTS OF CARBOXYLIC-ACIDS AS THEIR TRIMETHYLSILYL DERIVATIVES

Several potassium and sodium salts of monobasic, dibasic and tribasic organic acids, and sodium and calcium salts of fatty acids were directly silylated by Tri-Sil, a commercially available silylating reagent composed of a mixture of hexamethyldisilazane and trimetylchlorosilane in pyridine. The reaction mixtures were injected directly into a gas chromatograph without any further preparation. Quantitative GC peak area measurements indicated that the yields of trimethylsilyl (TMS) derivatives of the salts and the free acid counterparts were comparable. Identities of the derivatives were confirmed by GC-MS analysis. Carbon chain distributions of the fatty acid salts were determined by GC quantitation of the TMS derivatives formed by direct silylation of the salts and the fatty acids liberated from the salts. The present study indicates that the two results agree with each other favorably.