Comparison of micellar electrokinetic chromatography (MEKC) with capillary gas chromatography in the separation of phenols, anilines and polynuclear aromatics potential field-screening applications of MEKC.

Capillary electrophoresis (CE) is known to be complementary to liquid chromatography, but comparison of CE with capillary gas chromatography (GC) for applicable analytes has not been extensive. Capillary GC has been the preeminent separation technique for environmental analysis, but CE has yet to be applied systematically to the determination of environmental analytes. We present data on separations of three classes of semivolatile analytes of interest to environmental analysis: phenols, anilines and polynuclear aromatic hydrocarbons (PNAs). Standard GC conditions were used to illustrate typical separations observed on 30-m and 40-m columns. Rapid analyses were addressed using a high-temperature 15-m column of thinner film. CE separations employed borate buffer with sodium cholate as the micellar agent in micellar electrokinetic chromatography (MEKC). The effects of organic additives were studied using methanol, acetone and tetrahydrofuran. gamma-Cyclodextrin was also used in MEKC to enhance the separation of polynuclear aromatic hydrocarbons and to examine its effects on separations of phenols and anilines. Short capillaries effected very rapid (< 3 min) compound-class characterization, an approach which has potential use in site characterization/remediation (field-screening) studies.