Detection of flunixin meglumine in pork based on magnetic solid-phase extraction technology.

This study established two methods for detecting flunixin meglumine (FM) in pork. The MSPE-LC-MS/MS method utilizes the accuracy and quantifiability of liquid chromatography-tandem mass spectrometry. FM in pork can be accurately analyzed after optimizing the pretreatment, liquid phase conditions, and mass spectrometry parameters. It shows a good linear relationship (correlation coefficient > 0.999), with a detection limit of 0.2 μg/kg, limit of quantification of 0.6 μg/kg, spiked recovery rates of 90.6 % - 97.4 %, matrix effects of 96.7 % - 107.2 %, intra-day precision of 1.4 % - 5.6 %, and inter-day precision of 4.3 % - 11.5 %. The RP-MSPE-CGIA method combines the separation performance of reversed magnetic solid-phase extraction and the rapidness of colloidal gold immunochromatography. By optimizing conditions, it successfully extends the dairy product detection method to pork. It is easy to operate, has a detection limit of 5 μg/kg, and detection time less than half of MSPE - LC-MS/MS. Experiments show that the two methods complement each other in advantages and can meet the detection requirements of FM in pork in different scenarios.