PHOSPHATED SURFACTANTS AS PSEUDOSTATIONARY PHASE FOR MICELLAR ELECTROKINETIC CHROMATOGRAPHY - SEPARATION OF POLYCYCLIC AROMATIC-HYDROCARBONS

A double alkyl chain di(2-ethylhexyl)phosphate (DEHP) is introduced as a potential anionic micellar pseudophase for a wide range of benzene derivatives and/or polycyclic aromatic hydrocarbons (PAHs). Several pa rameters such as concentration of phosphated surfactant, type and conc entration of organic solvents (acetonitrile, isopropanol, and methanol ), as well as capillary electrophoresis separation voltage were optimi zed to enhance resolution, efficiency and selectivity as well as to ma ximize peak capacities. The migration times and selectivity order for a number of PAHs differ significantly, depending on the type of organi c solvent added to the DEHP surfactant. Acetonitrile at a concentratio n of 30% v/v in combination with 100 mM DEHP gave optimum separation f or a mixture of 21 benzene derivatives and PAHs in under 16 min.