A rapid screening and determination method, in conjunction with a database for confirmation, was established based on 66 antibiotic compounds using ultra-high performance liquid chromatography-linear ion trap/Orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS). The analytes were extracted with acetonitrile using ultrasonic extraction. The separation was performed on a C18 column (100 mm×2.1 mm, 1.8 μm) with a gradient elution of 0.1% (v/v) formic acid and acetonitrile. The retention time and accurate mass of the precursor ion were used for rapid screening in positive ionization mode, with the fragment ions obtained by higher energy collisional dissociation used for confirmation. The results indicated that each compound showed good linearity with a correlation coefficient of R2>0.99. The limits of detection (LODs) were in the range 2-4 μg/kg, and the limits of quantification (LOQs) were in the range 5-10 μg/kg. The average recoveries at three levels (1LOQ, 10LOQ, and 30LOQ) were between 58.2% and 119.1%, and the relative standard deviations (RSDs) were between 1.03% and 11.9%. The method is simple, rapid, reliable, and accurate, which is suitable for rapid screening and determination of the 66 antibiotic compounds in cosmetics.
Keywords: antibiotics; cosmetics; linear ion trap/Orbitrap high resolution mass spectrometry(LTQ/Orbitrap MS); ultra-high performance liquid chromatography(UPLC).