Abstract: A two-dimensional liquid chromatography (2D-LC) system was constructed with improved trap column interface. Weak anion exchange (WAX) LC was used as the first dimension separation mode and reversed-phase (RP) LC as the second dimension. Two 35 mm long columns (column 1 and column 2) were used as trap columns to retain the fraction from the first dimension, and forward-flushing was employed to pre-separate the components when the trap column was connected to the second dimension. The interface greatly increases the efficiency of the second dimension column without losing the separation speed. Rat serum sample was separated on this system to evaluate the performance of the constructed system. The viscous fingering (VF) phenomenon was generated attribute to the difference in the velocities of the mobile phases of the two dimensions. The separation efficiency was theoretically increased by 70% when the 35 mm trap columns were used in the forward-flush mode.

Key words: improved trap column interface, proteomics , rat serum, comprehensive two-dimensional liquid chromatography