Rapid Determination of Salicylic Acid in Cosmetics by UPLC-MS/MS

A rapid method of UPLC-MS/MS for the determination of salicylic acid in cosmetics was proposed. The sample was dissolved with methanol and extracted vortically for 20 min. After centrifugation, supernatant was taken for separation by using the column ACQUITYTM BET C18 (2.1 mm×100 mm, 1.7 μm) and using the mixed solution of acetonifrile and formic acid water solution (0.3+99.7), mixed in the ratio of 6 to 4, as mobile phase. The content of salicylic acid was determined by MS/MS. The positive electrospray ionization as well as multiple reactions monitoring mode was used in the detection. The isotope internal standard method was used for quantification of salicylic acid. Linearity range of salicylic acid was kept from 1.0 to 5.0×103μg·L-1, with limit of detection (3S/N) of 0.15 μg·L-1 and limit of determination (10S/N) of 0.50 μg·L-1. The proposed method was applied to the analysis of 8 cosmetic samples, giving values of recovery in the range from 97.3%-107.0% and RSD (n=5) in the range from 2.0%-3.8%.