Extraction and identification of matrine-type alkaloids from Sophora moorcroftiana using double-templated molecularly imprinted polymers with HPLC-MS/MS.

Double-templated molecularly imprinted polymers with specific recognition of three matrine-type alkaloids were prepared using matrine and oxymatrine as the template molecules. An approach based on double-templated molecularly imprinted solid-phase extraction coupled with high-performance liquid chromatography and tandem mass spectrometry was then developed to extract and purify matrine, oxymatrine, and sophocarpine from Sophora moorcroftiana in the Tibetan plateau herbs. The polymers were characterized by Fourier-transform infrared spectroscopy and scanning electron microscopy. Their adsorption characteristics were evaluated using adsorption kinetics, isotherms, selectivity, and recycling experiments. This polymer exhibited excellent molecular recognition ability and good selectivity. The obtained polymers as adsorbent was further used for the determination of three matrine-type alkaloids coupled to high-performance liquid chromatography with tandem mass spectrometry, the recoveries of three matrines spiked at three concentration levels in samples were 73.25-98.42% (n = 5) with a relative standard deviation less than 6.82%. The limits of detection for the method were 9.23-15.42 µg/kg (S/N = 3). This proposed method was assessed to be an effective method for simultaneous extraction, isolation, and identification of matrine, oxymatrine, and sophocarpine from Sophora moorcroftiana.