Interface apparatus for capillary electrophoresis to a

Abstract

An apparatus for collecting samples from capillary electrophoresis (CE) for matrix-assisted laser desorption ionization (MALDI) mass spectrometry (MS) is disclosed. The apparatus has a capillary, a metallic support, a porous member, and a power supply for applying an electrical potential between the porous member and an inlet end of the capillary to drive the sample through the capillary during CE. The capillary transmits a sample from the inlet end to the exit end during capillary electrophoresis. The metallic support supports the porous membrane such that the porous membrane contacts the capillary exit end during CE. The metallic support (with the porous membrane) is suitable for placing in a mass spectrometer to act as a repeller for MALDI. The porous member has at least a portion thereof that is generally concentric with the capillary exit end and contacts the porous membrane during CE. The capillary exit end and the metallic support are adapted to lift the capillary exit end from the porous membrane and reposition it on the porous membrane at a different location to deposit noncontinuously different fractions of the sample exiting the capillary on the porous membrane. When an electrically conducting liquid is present in the porous member, it provides electrical communication between the capillary exit end and the power supply.