To establish a high-performance liquid chromatography quadrupole time-of-flight mass spectrometry (HPLC-Q TOF MS) method for the simultaneous analysis of illegal 4 anti-obesity small molecule drugs and 4 glucagon-like peptide-1 (GLP-1) peptide additives.

The samples were extracted by ultrasound using 50% acetonitrile as the extraction solvent. After centrifugation, the supernatant was taken and separated using an Agilent EC-_C18 chromatographic column (150 mm×3.0 mm, 2.7 μm). Acetonitrile (0.1% formic acid) and water (0.1% formic acid) were used as mobile phases, with gradient elution at a flow rate of 0.3 mL·min^-1 and column temperature of 40 ℃. Adopting positive ion full scanning and target ion secondary fragment scanning methods, with a fragmentation voltage of 150 V. The scanning range of the primary mass spectrometry was m/z 100-3 200, and the scanning range of the secondary mass spectrometry was m/z 50-3 200, with a scanning speed of 1 mass spectrum per second. Establish a data spectral library based on the chromatographic retention time, primary mass spectrometry, and secondary mass spectrometry information of the reference standard, and confirmed the structure through database comparison.

The screening detection limit for peptides was 0.5 µg·mL^-1, while small molecular drugs was 0.05 µg·mL^-1. The recoveries were in the range of 79.4% to 115.8%，with the relative standard deviations of 0.21% to 9.7%. Using this method, 20 batches of anti-obesity drugs were tested, in which semaglutide was identified in 4 samples and sibutratmine was identified in 1 batche.

Compared with the complementary method No. 2012005 by the China Food and Drug Administration, the method established in this study can simultaneously analyze small and large molecules (the relative molecular mass<5 000), featuring high efficiency and accuracy.