On-line coupling of supercritical fluid extraction to capillary column electrodriven separation techniques

An interface for on-line supercritical fluid extraction-capillary electro-d riven separation technique (SFE-CEST) analysis was developed in order to ex plore the advantages of both techniques, SFE and CEST. The key aspect of th e proposed system is the developed interface that includes a sample concent rator based upon solid phase extraction technology. The developed instrumen t was evaluated by using two different sets of samples; one includes a mixt ure of s-triazines (ametryn, atrazine, and simazine) and the other includes a carbamate (carbaryl). The extractions were performed at 50 degrees C und er 200 or 250 atm depending upon the analyte being the extract directed to a CE system by the interface and analyzed in the micellar electrokinetic ca pillary chromatography (MECC) mode. Although not yet optimized, recoveries ranging from 65% for s-triazines to 70% for carbaryl were achieved as the v ery preliminary results. The total (extraction, concentration, and analysis ) time was about 50 minutes in both studied cases. (C) 2000 John Wiley & So ns, Inc.