Determination of Menbutone Residues in Edible Swine Tissues Based on Solid-Phase Extraction and RP-HPLC

Background: Menbutone is widely used as a veterinary choleretic drug in many countries. There was no publicly available analysis method for the determination of menbutone residues in swine tissues. It is necessary to establish a method to control the maximum residue limit and ensure food safety of the public. Objective: The aim of this study is to establish an analytical method for the simultaneous determination of menbutone in muscle, fat, liver and kidney tissues from swine. Methods: MBT residue was extracted by acetonitrile from the tissues then purified by using a C18 solid phase extraction (SPE) cartridge and an alkaline alumina (ALA) SPE cartridge. MBT was detected by RP-HPLC and separation was achieved on a Shim-pack VP-ODS C18 HPLC column using phosphoric acid solution (0.5%, v/v) and acetonitrile (45/55, v/v) at a flow rate of 1.0 mL/min. The effluent was monitored at 235 nm, and the column temperature was set to 30°C. Results: MBT eluted at 6.3 min and no interfering peak nearby was observed. This linearity within the concentration range of 0.02 (LOQ) and 12 μg/mL (r2>0.9999, n=6). The accuracy ranged from 74.07 to 110.83% of the actual values. Intra and inter-day precision were within 15.11%. In the application study, MBT was detectable in continuously dosing MBT 10 μg/g/day to healthy swine for 7 days. Conclusion: The proposed method has specificity, accuracy, and sensitivity, with an excellent linear relationship that successfully applied to swine tissues.