SIMULTANEOUS SUPERCRITICAL FLUID DERIVATIZATION AND EXTRACTION

Simultaneous supercritical fluid derivatization and extraction (SFDE) was investigated as a rapid alternative to liquid solvent extraction followed by derivatization for analysis by gas chromatography (GC). Addition of a commercially available silylation reagent, tri-sil concentrate, directly to the sample matrix, enables extraction of analytes from samples that were previously exhaustively extracted with conventional supercritical fluid extraction (SFE). The SFDE extracts were collected, ready for GC analysis without additional derivatization, not only resulting in time savings but also in improved extraction yield of both derivatized and underivatized species. In addition to making polar compounds more soluble in the supercritical extracting fluid through derivatization, the derivatization reagent is though to compete with the analyte for active sites of the matrix, thus displacing compounds from the matrix. Application of SFDE for the extraction and analysis of roasted coffee beans, roasted Japanese tea, and marine sediment is demonstrated.