Dual Detection for Capillary Isoelectric Focusing with Refractive Index Gradient and Absorption Imaging Detectors

Abstract

A unique imaging detector was constructed for capillary isoelectric focusing (CIEF) by combining a selective optical absorption imaging detector with a universal refractive index gradient imaging detector. All sample zones focused inside a 100-μm-i.d., 4-cm-long capillary by isoelectric focusing were detected in a real-time fashion by the universal imaging detector, and their spectroscopic properties were measured by the absorption imaging detector almost simultaneously. The refractive index gradient imaging is based on a dark-field Toepler-Schlieren system