PDMS Microchip Capillary Electrophoresis for Determination of Thiol Compounds

摘要

A fast and sensitive method for the determination of thiol compounds including homo-cysteine,glutathione and N-acetyl-l-cysteine using microchip capillary electrophoresis was proposed.The microchip was made from an elastomeric material-poly(dimethylsiloxane)(PDMS).The microchip configure-ation consists of a top layer of PDMS containing of injection and separation channels,reservoirs and a gold microwire sealed with a bottom layer of PDMS.A gold microwire was used as the working electrode and platinum microwire was used as counter electrode.The pulsed amperometric detection(PAD) was applied for determination of these thiol compounds.The experiments were carried out with 20 mM MES and 1 mM SDS buffer(pH 6.0).In order to optimize the conditions,detection and separation potential,pH buffer,injection time,and PAD parameters were studied.Homocysteine,glutathione and N-acetyl-L-cysteine can be separated and detected in less than 2 min at the detection potential of +0.8 V,separation potential of +1200 V,and injection time of 20 s,with good reproducibility and sensitivity.