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SummaryComponents of hamster feces ranging from low molecular weight fatty acids through the expected range of triglycerides have been eluted in a single SFC run with simultaneous pressure and temperature pmgramming.Temperature programming from 140°C to 240°C was required to provide optimum conditions for separation of the fatty acids and to move the elution region of the sterol esters away from that of the triglycerides. Data from molecular weight triglycerides are not eluted using conventional capillary gas chromatography (GC) 121. High temperature GC extends the applicability of the technique to less volatile components [3]. However, certain higher molecular weight, unsaturated sterol esters and unsaturated triglycerides may undergo thermal decomposition reactions at the temperatures required for their elution [4]. chemical ionization and electron impact mass spectrometry of compounds separated by SFC were used to confirm identities suggested by retention measurements and to provide tentative identities of unknown compounds.SFC with flame ionization detection was used to compare Soxhlet extraction, off-line supercritical fluid extraction (SFE), and on-line SFE of the feces. Although samples obtained by Soxhlet extraction and SFE produced very similar chromatograms, SFE required far less time and consumed much smaller quantities of organic solvent.

Abstract. Low molecular weight poly(acry1ic acid) (PAA) samples were derivatized to increase their solubilities in the supercritical mobile phase, C02. tert-Butyldimcthylsilyl ester derivatives provided better chromatographic performance and molecular weight range than did trimethylsilyl or methyl esters. Individual oligomers were resolved through approximately n = 28. Higher oligomers, up to approximately n = 45 (corresponding to an underivatized molecular weight of more than 3300), were eluted from the column but were not resolved. Ammonia chemical ionization and electron ionization supercritical fluid chromatography-mass spectrometry data revealed that the PAA terminal groups of the samples studied were sulfonate and hydrogen.