Abstract:

A UPLC-MS/MS method for the determination of pyocyanin and pyoluteorin in cosmetics was established. The samples were dispersed by saturated sodium chloride solution in vortex, then acetonitrile was added for ultrasonic extraction, and the upper organic phase was taken for purification analysis. Phenomenex Kinetex （2.6 µm, 50 mm×3.0 mm） column was used for separation. Gradient elution was performed with formic acid water-methanol as mobile phase. External standard method was used for quantification. The results showed that the two compounds could be effectively separated within 5 min, and showed a good linear relationship in the mass concentration range of 1-100 µg/L, with correlation coefficients greater than 0.993. The limits of detection were 0.05 mg/kg, and the limits of quantitation were 0.10 mg/kg. At 0.10, 0.25 and 0.50 mg/kg，the average recoveries of water agent and cream samples ranged from 85.58% to 102.96% and the relative standard deviations （RSD） were 1.54% to 3.77%. The intra-day RSD ranged from 0.51% to 3.68%，and the inter-day RSD ranged from 1.95% to 4.24%. The method has good precision and high accuracy, which is suitable for the determination of pyoluteorin and pyocyanin in various cosmetics.

Key words: UPLC-MS/MS, cosmetics, pyoluteorin, pyocyanin, detection