The　fabrication　of　effective　microchip　liquid　chromatography　(LC)　systems　tends　to　be　limited　by　the　availability　of　suitable　chromatographic　columns.　Herein,　we　developed　a　glass　microchip　LC　system　in　which　porous　single-particle　silica　was　adopted　as　frits　and　a　freeze-thaw　valve　was　utilized　to　achieve　sample　injection　without　interfering　with　sampling.　The　fabrication　of　single-particle-frit-based　packed　columns　did　not　require　an　additional　packing　channel,　thus　avoiding　dead　volumes　within　the　channel　interface　that　can　influence　chromatographic　separation.　Further,　the　length　of　the　packed　column　could　be　adjusted　using　the　location　of　single-particle　frits　within　the　column　channel.　The　fabricated　frits　exhibited　high　mechanical　strength,　good　permeability,　and　tolerance　for　high　pressures　during　chromatographic　separation.　In　particular,　the　developed　microchip　LC　system　was　able　to　withstand　high　separation　pressures　of　more　than　5000　psi.　The　microchip　LC　system　was　applied　to　the　separation　of　neurotransmitters.　Three　different　monoamine　neurotransmitters　were　completely　separated　within　5　min　with　theoretical　plate　numbers　on　the　order　of　100,000　plates　m(-1).　The　microchip　LC　system　has　a　potential　for　application　in　a　variety　of　fields　including　environmental　analysis,　food　safety,　drug　analysis,　and　biomedicine.