Abstract:

This article presents the designing and fabrication of a microfluoidic chip with an integrated supported-liquid-membrane extraction-back-extraction and chip-based capillary electrophoresis system(SLMEBE-CCE).  A 3-dimensional channel network for the SLMEBE-CCE system was fabricated with a four-layer glass/PTFE-membrane hybrid structure.  With a gravity pump for sample and back-extraction solution delivery and  a multi-channel high-voltage supply for CCE separation,  the microchip with the coupled SLMEBE-CCE system was demonstrated by the pre-concentration, separation and detection of a mixed solution of fluorescein and butyl-rhodamine B.  Compared to chip-based CCE without SLMEBE, the developed SLMEBE-CCE system produced a 7-fold increase in the signal of the model analyte of fluorescein and a 4-fold decrease in the signal of the model co-existing compound of butyl-rhodamine B.

Key words: Microfluidic chip; Capillary electrophoresis; Supported liquid membrane extraction and back extraction; Pre-concentration; Sample cleaning-up