Abstract

SIMULTANEOUS DETERMINATION OF ANESTHETIC DRUGS AND FLUOROQUENOLONE ANTIBACTERALS IN HUMAN URINE BY CAPILLARY ELECTROPHORESIS WITH ELECTROCHEMILUMINESCENCE DETECTION

Liqing Li, Ming Su, Peiyun Chen and Hanwen Sun*

ABSTRACT

A new method was developed for the simultaneous determination of anesthetic drug (bupivacaine and procaine) and fluoroquinolone antibacterials (enrofloxacin, gatifloxacin and pefloxacin) in human urine by capillary electrophoresis‒electrochemiluminescence detection with Ru(bpy)3 2+. Conditions of the separation and detection were investigated and optimized. It was proved that 15 mM phosphate buffer (pH 9.0)‒acetonitrile (85:15, v/v) could achieve the target analytes to be separated, and the high sensitivity of detection was obtained by using the detection potential at 1.15 V and 5 mM Ru(bpy)3 2+–60 mM phosphate buffer at pH 7.5 in the detection reservoir. The linear range for procaine, bupivacaine, enrofloxacin, gatifloxacin, and pefloxacin was 0.2‒100, 0.1‒100, 0.1‒80, 0.06‒80, and 0.1‒100 μg/mL, respectively, with correlation coefficient (r) of ≥0.996, their detection limits were 0.06, 0.02, 0.01, 0.02, and 0.03 μg/mL. Relative standard deviations of both ECL intensity and migration time were 3.3, 3.5, 3.1, 3.4, and 3.7%, and 1.1, 1.2, 0.9, 1.0, and 1.2%, respectively, for 11 determinations of mixed standard solutions at 6 μg/mL for each analyte. A baseline separation for the five analytes was achieved within 500 s. The developed method was successfully applied for the analysis of spiked urine. The recovery at three spiked levels was in the range of 95.0–103%, with RSD of 2.9–3.6%. Mechanism of ECL was also discussed.

Keywords: Capillary electrophoresis, electrochemiluminescence, anesthetics, fluoroquinolones, Human urine