A　monolithic　stationary　phase　was　prepared　by　in　situ　copolymerization　of　2-hydroxyethyl　methacrylate　(HEMA),　ethylene　dimethacrylate　(EDMA),　and　methacrylic　acid　(MAA),　in　a　binary　porogenic　solvent　consisting　of　toluene　and　1-dodecanol.　The　resulting　monolith　was　evaluated　as　a　hydrophilic　interaction-capillary　electrochromatography　(HI-CEC)　stationary　phase　under　the　mode　of　pressurized　capillary　electrochromatography　(pCEC).　Effects　of　the　buffer　pH,　salt　concentration　and　the　mobile　phase　composition　on　the　electroosmotic　flow　(EOF)　velocity　and　the　retention　factors　of　the　compounds　were　investigated.　The　generation　of　cathodic　EOF　under　a　broad　pH　range　was　attributed　to　the　presence　of　the　carboxyl　groups　on　the　surface　of　the　polar　stationary　phase.　The　carboxyl　groups　offered　at　the　same　time　the　possibility　of　weak　electrostatic　interaction　with　analytes.　The　separation　mechanism　of　the　monolithic　column　was　discussed　in　detail.　It　was　found　that　the　separation　mechanism　of　charged　solutes　could　be　attributed　to　a　mixed　mode　of　HI　and　weak　electrostatic　interaction,　as　well　as　the　effect　of　electrophoresis,　while　the　separation　of　neutral　solutes　was　based　on　the　hydrophilic　interaction　at　high　acetonitrile　(ACN)　content.　©　2008　Elsevier　B.V.　All　rights　reserved.