High-speed separations by electrokinetic chromatography using polymeric pseudostationary phases

High-speed separations of hydrophobic solutes by capillary-based electrokinetic chromatography (EKC) are reported in this short communication with analysis speed comparable to that of high-speed capillary electrochromatography (CEC). Polymeric pseudostationary phases can provide highly efficient separations of hydrophobic solutes in the presence of high concentration of organic solvents, and some of them have low electrical conductivity compared with sodium dodecyl sulfate micelles, so that a high electric field can be used without a significant loss of efficiency or resolution. Using poly(sodium 2-acrylamido-2-methylpropane sulfonate-co-dihydrocholesteryl acrylate) as the pseudostationary phase on a capillary column of 31 cm total length (23 cm effective length) and under an electric field strength of 962 V/cm, a separation of 12 out of 15 polycyclic aromatic hydrocarbons (PAHs) was achieved within 138 seconds. The RSD of retention times were less than 1.5% (n = 25).