Coupled SFE-GC: A Rapid and Simple Technique for Extracting, Identifying, and Quantitating Organic Analytes from Solids and Sorbent Resins

Supercritical fluid extraction (SFE) can be directly coupled to capillary gas chromatography (SFE-GC) with a standard on-column gas chromatographic injector. SFE-GC yields maximum sensitivity and minimizes the chances for degradation and loss of analyte species by quantitatively transferring all of the extracted analytes into the capillary gas chromatographic column for subsequent cryogenic trapping and gas chromatographic analysis. Chromatographic peak shapes obtained by SFE-GC compare favorably with those obtained by standard on-column and split injections of samples in liquid solvents. SFE-GC allows an entire analysis scheme including extraction, analyte concentration, and GC separations to be performed in a total time of less than one hour per sample, compared to several hours or even days when liquid solvents are used for sample extractions. This article describes the use of coupled SFE-GC for the rapid extraction, concentration, identification, and quantitation of organics from a variety of samples. Comparisons of SFE-GC with conventional extraction and GC analysis methods, specialized experimental procedures, and future needs in SFE-GC research are also discussed.