Capillary electrophoresis of aminoglycosides with argon-ion laser-induced fluorescence detection

A new analytical method for aminoglycosides (kanamycin, bekanamycin, paromomycin and tobramycin) based on capillary electrophoretic separation and argon-ion laser-induced fluorescence detection has been developed. 6-Carboxyfluorescein succinimidyl ester (CFSE) was used for precolumn derivatization of the non-fluorescent aminoglycosides. Optimal separation and detection were obtained with an electrophoretic buffer of 30 mM sodium borate (pH 9.0) and an air-cooled argon-ion laser (excitation at 488 nm, emission at 520 nm). The concentration limits of detection in aqueous solution were 3.9–8.2 nM. Combined with a simple cleanup procedure, this method can be applied to the determination of aminoglycosides in human plasma. A calibration curve ranging from 0.15 to 30 μM was shown to be linear. The limits of detection of aminoglycosides in human plasma were between 14.4 and 24.0 nM. Recoveries of spiked aminoglycosides in human plasma were between 92 and 105%.