High-performance liquid chromatography determination of anilines with fluorescent detection and pre-column derivatization

A simple, sensitive, and rapid reverse-phase high-performance liquid chromatography (RP-HPLC) method for the determination of anilines in water is proposed. The use of 2,7-diethylamino-2-oxo-2H-chromen-3-yl-benzothiazole-6- sulfonylchloride (coumarin 6-SO₂Cl) as a fluorigenic-labeling reagent was investigated. The label reacted with aniline within 30 min under mild conditions (ambient temperature, pH 9.0) to give sulfonamides that were separated by RP-HPLC employing fluorescence detection with an excitation wavelength of 470 nm and an emission wavelength of 520 nm. The optimum conditions for fluorescence, derivatization, and chromatographic separation were established. The calibration curves were linear for the range 0-800 ppb. The proposed method was applied for the determination of anilines in spiked drinking water samples and irrigation water samples with recoveries of 90.0-103.9% and relative standard deviations of 1.2-4.7%, respectively. This method showed good accuracy and repeatability that can be used for the quantification of aniline in real samples.