Ion chromatography combined with online electrochemical derivatization and fluorescence detection for the determination of carbamazepine in human plasma

This paper describes the determination of carbamazepine (CBZ) in human plasma using ion chromatography combined with online electrochemical derivatization and fluorescence detection. Separation of CBZ with anion exchange column was demonstrated to be feasible using either basic (10 mM NaOH) or acidic (0.1 M H3PO4) reagent with a small amount of acetonitrile (ACN) added as eluent. Electrochemical derivatization of CBZ into a strongly fluorescent product, which could be carried out only under the acidic condition, was investigated via the previously reported electrolytic cell (EC), as well as two modes of acidification. The linear range of CBZ for human plasma was between 10–2000 μg L−1 under the optimized experimental conditions. The limit of detection (LOD, S/N=3) was 1.3 μg L−1 and the relative standard deviation (RSD, n=7) was 2.6%. Better sensitivity and selectivity of the present method were demonstrated in comparison with ion chromatography with ultraviolet detection (IC-UV). The spiked recoveries of CBZ in 2 human plasma samples were 78.5 and 114%, respectively.