title: Simultaneous determination of malondialdehyde and ofloxacin in plasma using an isocratic high-performance liquid chromatography/fluorescence detection system.
abstract: This study establishes the applicability of using high-performance liquid chromatography (HPLC) with fluorescence detection for the simultaneous determination of malondialdehyde (MDA) and ofloxacin (OFL). The MDA and OFL were separated through a reverse-phase C18 column (250 mm x 4.6 mm) at a flow rate of 1.0 mL min(-1) and then detected using a fluorescence detector (excitation: 532 nm; emission: 553 nm). The separation conditions were optimized by varying the concentration and pH of the phosphate buffer and the percentage of organic solvent; the optimal mobile phase was a mixture of 50 mM phosphate buffer (adjusted to pH 5.8 with potassium hydroxide) and methanol (45:55, v/v). The retention times of MDA and OFL were 3.6 and 5.9 min, respectively, with detection limits (at a signal-to-noise ratio of 3) of 0.015 and 4.0 microM, respectively. This method afforded linear responses between the MDA and OFL concentrations and the HPLC peak areas within the ranges 0.15-2.43 microM and 0.06-1.0 mM, respectively. The precisions of the determinations of MDA and OFL, measured in terms of relative standard deviations, were 1.6-5.0% and 1.9-3.6%, respectively, for intra-day assays and 1.0-4.3% and 0.3-1.8%, respectively, for inter-day assays. The average recoveries of MDA and OFL spiked in plasma were 100.4% and 98.8%, respectively. To the best of our knowledge, this paper describes the first practical analytical approach toward simultaneously monitoring the levels of MDA and OFL in plasma. The OFL-induced oxidative stress measured using this method indicated that OFL treatment did not markedly increase the level of MDA.
authors.affiliation: Graduate Institute of Pharmaceutical Sciences, Kaohsiung Medical University, Kaohsiung 807, Taiwan.
authors.forename: Guan-Wen
authors.initials: GW
authors.lastname: Cheng
authors.forename: Hsin-Lung
authors.initials: HL
authors.lastname: Wu
authors.forename: Yeou-Lih
authors.initials: YL
authors.lastname: Huang
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods; D005453:Fluorescence; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008315:Malondialdehyde / Q000097:blood*; D015242:Ofloxacin / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D008315:Malondialdehyde; D015242:Ofloxacin