Determination of Topiramate in Infant Plasma by High-performance Liquid Chromatography Using Fluorescence Derivatizing Agent

In this study,we developed a reversed-phase high-performance liquid chromatographic method using a fluorescence derivatizing agent for the determination of topiramate (TPM) in infant plasma.The method used 100μL plasma samples,and the HPLC separation was carried out on a Discovery HS-C 18 column (3μm,4.6 mm×150 mm) with phosphate buffer (pH 2.5 ; 25 mM)-methanol-acetonitrile (50 : 40 : 10 (v/v/v)) as the mobile phase at a 1.0 mL/min flow rate.TPM was detected using a fluorescence detector (λex/em : 470/537 nm).The quantification limit was 0.1μg/mL,and the intra- and interassay coefficients of variation were 0.8-7.1% and 1.3-9.3%,respectively.A specificity and selectivity study showed that there were no interfering peaks.Furthermore,correlation analysis of TPM concentrations measured by HPLC and LC/MS produced a correlation coefficient (γ) of 0.9825.