Abstract：Flunixin meglumine (FM) is the only animal-specific non-steroidal anti-inflammatory drug, and it is the most commonly used anti-inflammatory and analgesic drug in veterinary clinics. In recent years, with the expansion of its application scope, its adverse reactions gradually appeared, and the residues of Flunixin meglumine in animal meat gradually attracted people’s attention and attention. The current detection methods of FM include liquid chromatography-tandem mass spectrometry, and liquid chromatography. However, this method has disadvantages such as expensive equipment, cumbersome and complicated operation, which is highly unfavourable for rapid on-site detection. Surface-enhanced Raman spectroscopy (SERS) has the advantages of portability, rapid detection, fingerprint recognition, etc., which can overcome the chromatographic technology brought by on-site detection. Because of the inconvenience, it has been widely used in the rapid screening and detection of veterinary drug residues in recent years. Therefore, in order to realize the rapid detection of FM in pork, a rapid detection method of levamisole residues in pork by SERS was established. The gold sol was prepared by reducing potassium chloroaurate with sodium citrate. Through a single factor experiment, it was determined that when the volume ratio of sample to gold gel was 1∶3, the pH of the sample was 6, and no coagulant was added, the detection effect was the best. Combining density functional theory to calculate theoretical spectra, compare theoretical calculation spectra with solid Raman spectra, assigning vibration modes to characteristic peaks. Among them, the pyridine ring and benzene ring swing at 731, 1 085 and 1 376 cm-1 are C—H vibration on the benzene ring. After optimizing the extraction pretreatment method and the selection of extractant, a qualitative and quantitative detection method for FM in pork was established under the best detection conditions. In this method, the characteristic peaks of FM in the pork matrix are 731, 1 085 and 1 376 cm-1. Choose 731 cm-1 as the qualitative and quantitative peak, where the Raman intensity and the FM concentration have a good linear relationship within 1～250 mg·L-1, and R2 is 0.99. The actual concentration of the spiked samples was tested, the recovery rate was 89.61%～95.63%, and the RSD was 1.80%～3.30%. The method is simple, fast and stable in operation, and is beneficial to the rapid on-site detection of FM residues in pork.
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