Abstract:

An ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry method （UPLC-Q-TOF-MS） was established to identify 108 illegally added compounds in cosmetic and disinfectants. Samples were dispersed in a saturated sodium chloride solution, extracted by sonication with acetonitrile solution containing 0.05% formic acid, and frozen at 0 ℃ while centrifuged. Chromatographic separation was performed on a X-Bridge C₁₈ column （4.6 mm×100 mm, 3.5 μm） with gradient elution using 0.1% （volume fraction） acetic acid aqueous solution and acetonitrile as the mobile phases. The mass spectrum information of the tested compounds was collected by broadband collision-induced dissociation （bbCID） mode under the electrospray ion source and positive and negative ion scanning mode, and a screening database of 108 illegally added compounds was constructed. The effect of extraction solvent was investigated and the chromatographic and mass spectrometry conditions were optimized. The matrix effects and recovery of gel-, cream-, and powder-based cosmetics were also investigated. The results show that the detection limit of 108 compounds is 0.05-2.25 mg/kg, and the limit of quantification is 0.15-7.50 mg/kg. The correlation coefficient （R²） are greater than 0.99 in the corresponding liner concentration range. Average recoveries are in the range of 60.0%-122.1% at three spiked levels, and the relative standard deviations （RSDs） are 1.2%-23.3%. A total of 83 cosmetics and 50 antibacteriostatic samples are analyzed by this established method. Finally, lincomycin and lidocaine are detected in two batches of disinfection products. The contents of lincomycin and lidocaine are 5 024.4 mg/kg and 2.2 mg/kg, respectively. The optimized method is simple, accurate and suitable for rapid screening and simultaneous quantitative analysis of various illegally added compounds in cosmetics and disinfectants.

Key words: time of flight mass spectrometry, illegally added compounds, cosmetics, disinfectants