Determination of 8 Water-Soluble Colorants in Cosmetics by HPLC and Verified by LC-MS/MS

An analytical method based on HPLC-DAD was developed for the simultaneous determination of 8 water-soluble colorants in cosmetics. Cosmetic samples were extracted under ultrasonication. The filtrate was injected into HPLC, and detected at the wavelengths of 254 nm and 630 nm. Qualitative analysis of colorants was based on the retention times of the chromatogram and the ultraviolet spectra. Quantitative analysis was conducted by external standard methods. Furthermore, the results were confirmed by LC-MS/MS. The recoveries were 82.9%-104.0% with the relative standard deviations less than 5%. The limits of quantitation for 8 colorants are
2.5 mg kg^－1 and 10.0 mg kg^－1, respectively.