Determination the residues of matrine and oxymatrine in Liupao tea by UPLC-MS/MS with isotope internal standard method

Abstract

Objective: Taking Guangxi Liupao tea as an example, an UPLC-MS/MS analysis method with residual amounts of matrine and Oxymatrine was established. Methods: The prepared samples were subjected to optimized acetonitrile aqueous solution （80% acetonitrile+0.2% ammonia water） ultrasonic extraction, mobile phase: formic acid water and formic acid methanol （both 0.1%）, gradient elution, and internal standard method quantification. Results: It was linear in the range of 0.1～80.0 ng/mL, r was greater than 0.999 6, the detection limits of matrine and oxymatrine were 1.0 μg/kg, and the quantitative limits were 3.0 μg/kg, which met the regulatory determination requirements for the residue of matrine and oxidative matrine in tea. Through the spike verification, the recovery rate was in the range of 92.0%～104.7%, and the relative standard deviation （RSD） was less than 5.4%. Conclusion: Method combined with purification tube purification （147.7 mg PSA, 15.1 mg GCB, 887.2 mg magnesium sulfate）, using Kinetex 2.6 μm Biphenyl 100 chromatographic column （100 mm×3.0 mm） separation solves the problems of low extraction recovery rate and complex pre-treatment of matrine and oxymatrine, so that the symmetrical peak shape and strong anti-interference ability of matrine and oxymatrine.

Keywords

• liupao tea
• matrine
• oxymatrine
• uplc-ms/ms