POLYOL ESTER SYNTHETIC REFRIGERATION LUBRICANT ANALYSIS BY SUPERCRITICAL FLUID CHROMATOGRAPHY

摘要

Supercritical fluid chromatography with flame ionization detection has been applied to the analysis of polyol ester fluids used as synthetic refrigeration lubricants. Through the observation of the peak patterns obtained in the chromatograms, it is possible to gain knowledge of the carboxylic acids from which the esters were derived, polyol base structure, reaction scheme, and degree of reaction completeness, These results can be obtained in a qualitative to semiquantitative manner with minimal analysis of reference standards. In addition, it is possible through statistical techniques, and use of standards, to quantitatively determine the amount of the acids used in the esterification of the polyol. Quantitation of the amount of different polyols is possible without standardization. In addition, it is possible to detect and quantify any impurities and/or free hydroxy groups in the fluid. A final important capability is the detection and identification of performance-enhancing additive materials in the lubricants. Results are presented demonstrating each of these attributes, and a description of the method is provided.