Abstract: A method for the determination of 12 sulfonamides (SAs) (sulfanilamide, sulfamonomethoxine, sulfacetamide, sulfamethoxazole, sulfadiazine, sulfisoxazole, sulfathiazole, sulfadimethoxine, sulfamerazine, sulfaquinoxaline, sulfamethazine, sulfanitran) in cosmetics was developed by ultra performance liquid chromatography with photodiode array detector (UPLC-PDA). The chromatographic column used was Acquity UPLCTM BEHC C18 (50 mm×2.1 mm, 1.7 μm) and the mobile phase was acetonitrile-0.1% formic acid aqueous solution. A gradient elution program was utilized for the separation and determination. After liquid-liquid extraction, SAs were separated and detected by UPLC-PDA. The qualification analysis was done by using retention time and spectrum, and the quantification was based on the detection wavelength of 268 nm. The limits of qualification (S/N=3) and quantification (S/N=10) for 12 SAs were 1 μg/g and 2-3 μg/g, respectively. The correlation coefficient of linear calibration curve was over 0.9997 within the SAs concentration range of 1-25 mg/L (except sulfanitran 0.5-12.5 mg/L). At the spiked levels of 40 and 8 μg(except sulfanitran 20 and 4 μg), the average recoveries for 12 SAs were 86.8%-98.1% and 80.1%-96.9%, respectively. Relative standard deviations were less than 10%. Routine tests show that the method is simple, fast, and has a good separation efficiency. It can be routinely used for the determination of these SAs in cosmetics.

Key words: cosmetics , sulfonamides, ultra performance liquid chromatography (UPLC)