On-column amperometric detection of ofloxacin and pasiniazid in urine by capillary electrophoresis with an improved fractured joint and small dtection cell

摘要

An improved high-voltage electric field isolating joint and small detection cell have been carefully designed and fabricated. The joint possesses short steady time, high electric conductance efficiency and high perfonnance. The cell is convenient to install and remove the capillaries with and without the joint, as well as to fix, adjust and insert the fiicroelectrode into the detection capillary. Using the joint and the cell, an analytical method for determination of ofloxacin (Oflx) and pasiniaZid (Ipa) in urine by capillary electrophoresis with on-column amperometric detection was developed. The calibration lines were linear in the range of 10-100 mg I-I ofOflx and 1.0-50 fig I-I of Ipa, respectively. The detection limits were 8.5 mg I-I of Oflx and 0.80 fig I-I of Ipa. Their recovery ranged from 101 to 104%. The accuracy and intra-day and inter-day reproducibility of Oflx and Ipa were detennined with satisfactory results. This method was successfully used for detennining Oflx and Ipa in human urine.