Determination of doxorubicin in plasma by using CE coupled with in-column tapered optic-fiber light-emitting diode induced fluorescence detection

This paper proposes a novel strategy to enhance detection of doxorubicin in human plasma, using homemade CE combined with normal stacking mode (NSM). The detection system of CE named as in-column tapered optic-fiber light-emitting diode induced fluorescence detection system is economic and more sensitive that has been demonstrated in our previous work. The influence of sample matrix, BGE, applied voltage, and injection time on the efficiency of NSM were systematically investigated. The clean extracts were subjected to CE separation with optimal experimental conditions: Ethanol-water (1:1, v/v) was used as sample matrix, pH 4.12 15 mM sodium phosphate buffer solution containing 70% v/v ACN, applied voltage 23 kV and 45 s hydrodynamic injection at a height of 20 cm. The detection system displayed linear dynamic range from 6.4 to 1.13 × 10³ ng/mL with a correlation coefficient of 0.9990 and LOD 2.2 ng/mL for doxorubicin (DOX). The proposed CE method has been successfully applied to determine DOX in human plasma which the recoveries of standard DOX added to human plasma were found to been the range of 93.8-104.6%. The results obtained demonstrate that our detection system combined with NSM is a good idea to enhance sensitivity in CE for routine determination of DOX in some biological specimens.