Highly-sensitive micellar electrokinetic chromatographic analysis of dioxin-related compounds using on-line concentration

An application study of an on-line concentration technique of neutral analy tes for micellar electrokinetic chromatography (MEKC) was carried out in en vironmental analysis to enhance the UV detection sensitivity. Several dioxi ns and related compounds, such as dibenzofuran, dibenzo-p-dioxin, 2,3- and 2,7-dichlorodibenzo-p-dioxins, and 2,3,7-trichlorodibenzo-p-dioxin, were us ed as test solutes. For a highly sensitive separation and detection, cyclod extrin-modified MEKC (CD-MEKC) under acidic conditions was employed as a se paration mode and stacking using reverse migrating micelles and a water plu g (SRW) as an on-line concentration technique. Almost a 200-fold gain in de tection sensitivity was obtained for the model compounds in SRW-CD-MEKC com pared to that in normal CD-MEKC without on-line concentration and the limit of detection was found to be around 0.1 ppm for each solute. (C) 1999 Else vier Science B.V. All rights reserved.