Screening of 203 Pesticide Residues in Hair Loss Prevention Cosmetic Containing Plant Extracts by UHPLC-Q-TOF-MS

A mass spectrometry database of 203 pesticides was established by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UHPLC-Q-TOF-MS), which was used for the screening of pesticide residues in hair loss prevention cosmetic containing plant extracts. The single standard solutions of 203 pesticides were analyzed by UHPLC-Q-TOF-MS, and the obtained MS information containing mass-to-charge ratio (m/z) of the precursor and product ions and their abundance ratio, as well as retention time of each pesticide were imported into UNIFI software to establish the database of 203 pesticides. The 24 batches of liquid cosmetics were extracted with methanol. After centrifugation, the solution was filtered by 0.22 μm microporous membrane. The mobile phase containing water and methanol was supplemented 10 mmol·L^-1 ammonium acetate-acetic acid solution (pH 5.0), and electrospray ionization source with positive and negative modes was used for ionization. MS data of the samples were collected with data-independent acquisition mass spectrometry mode, and at least one precursor ion and one product ion were detected. The MS data obtained were matched with the retention time, m/z and abundance ratios of the precursor and product ions of pesticide in the database. When the absolute value of the absolute deviation of retention time was within 0.2 min, the absolute values of the relative deriations of m/z of precursor and product ions were less 5×10^-6, and the intensity response was greater than 500, it was indicated that the pesticide was confirmed in the sample. The results showed that azoxystrobin was detected in one from 24 batches of the samples.