The method of on-line supercritical fluid extraction/Fourier transform infrared spectrometry (SFE/FT-IR) has been applied to the analysis of fiber finishes on fiber/textile matrices. Three different fiber polymer types were examined, each requiring a different finish. Finishes ranged from a single-component poly(dimethylsiloxane) oil to more complex multicomponent finishes that included various surfactants, fatty acid esters and soaps, antioxidants, and oils. The three fiber types tested were polyurethane, polyamide, and aramid. Off-line extraction showed all three finishes to be over 89% extractable with pure CO> Calibration curves were established for the three finishes, with relatively low error and reasonable detection limits (i.e., 0.2-5 µ8).

A system Is described wherein the supercritical fluid extracts of compounds can be analyzed on-line by FT-IR without prior chromatographic separation. A 1-m-X 0.010-ln.-i.d. stainless steel transfer line was used between the extraction vessel/ system cryotrap and the high-pressure IR flow cell. Extraction can be directly conducted as static, dynamic, static-dynamic, or dynamlc-cryotrap with minor system alterations. Quantitation was performed by Integrating the area of the extract plug, plotted In terms of detector signal versus time. The system was perfected for the extraction and quantification of n-tetracosane (C24) from Cellte, but has subsequently been applied to more complex systems, such as flber/fabrlc finishing oils, with comparable success. The detection limit for C24 by on-line SFE/FT-IR was calculated to be 74 ng. The relative speed and reproducibility of the method make It a viable alternative to the liquid extraction/1R methods used In Industrial process analysis that require Increasingly EPA-regulated solvents.

New strategies for sample introduction in supercritical fluid chromatography are reviewed. Both open tubular and packed column systems are examined as the injection demands of each column type are addressed. In addition to advances made in solvent injection methods, supercritical fluid extraction (SFE) is discussed as a solventless injection technique for supercritical fluid chromatography.

Xenon is compared to carbon dioxide as a mobile phase for super critical fluid chromatography/Fourier transform infrared spectrometry. The study showed xenon to be comparable to carbon dioxide in terms of resulting chromatography for non‐polar analytes. Xenon was confirmed to be a very poor mobile phase, however, for polar analytes. It was determined that small wavenumber shifts in the infrared spectra of probe analytes occurred as either the density or temperature of the mobile phase was increased. The degree of these shifts was often similar for xenon and carbon dioxide. Analyte spectra for five different compounds were produced in both super critical xenon and carbon dioxide and compared to condensed phase and vapor phase library spectra. In all cases, carbon dioxide spectra were readily matched to their corresponding vapor phase spectra, despite having blanked portions of the spectrum due to carbon dioxide infrared absorption. Xenon produced technically superior spectra without such blanked regions, but at a much higher economical cost than carbon dioxide and with no real improvement in terms of library matching.