USE OF DIFFERENT SURFACTANTS (SODIUM DODECYL-SULFATE, BILE-SALTS AND IONIC POLYMERS) IN MICELLAR ELECTROKINETIC CAPILLARY CHROMATOGRAPHY APPLICATION TO THE SEPARATION OF ORGANOPHOSPHORUS PESTICIDES

Sodium dodecyl sulfate (SDS) is the most widely used surfactant in mic ellar electrokinetic capillary chromatography (MECC), The separation o f highly hydrophobic compounds by MECC can be difficult because they w ill completely associate with the micelles and will elute at the end o f the elution window. The addition of organic solvents to the running buffer may enhance the separation, but they can also inhibit micelle f ormation. An alternative is the use of different surfactant systems su ch as bile salts and ionic polymers. In this work, four different surf actants (SDS, sodium cholate, sodium deoxycholate and Elvacite 2669) h ave been studied by using two organophosphorus pesticides (chlorpyriph os-methyl and -ethyl) as model compounds. (C) 1997 Elsevier Science B. V.