A liquid chromatography-tandem mass spectrometry method to determine total matrine residues in edible porcine tissues and its application in a tissue residue depletion study

Matrine (MT), a phytochemical with various anti-infective activities, is expected to become a therapeutic agent against bacterial, viral, and parasitic infections in pigs. However, food safety risks associated with MT have not yet been evaluated. In the present study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed to determine total MT residues in edible porcine tissues. The tissue samples were hydrolyzed with trypsin to release non-extractable MT. The hydrolysates were extracted with a trichloroacetic acid solution. Tissue extracts were purified using solid-phase extraction and subjected to LC-MS/MS. The method was fully validated according to the United States Food and Drug Administration (USFDA) guidelines and applied to investigate the tissue residue depletion of MT in pigs. Significant accumulation of MT was observed in edible porcine tissues. Notably, MT showed no persistent tissue residue in this study and could be accepted as a safe anti-infective agent in pigs.