Selective analysis of aristolochic acid I in herbal medicines by dummy molecularly imprinted solid-phase extraction and HPLC.

In this study, surface molecularly imprinted polymers were prepared as the selective sorbents for separation of aristolochic acid I in herbal medicine extracts by a facile approach. A less toxic dummy template, ofloxacin, was used to create specific molecule recognition sites for aristolochic acid I in the synthesized polymers. The polymers were characterized by Fourier-transfer infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, elemental analysis, and nitrogen adsorption-desorption test. The adsorption capacity was calculated using adsorption kinetics, selectivity, and recycling experiments. The obtained polymers exhibited high thermostability, fast equilibrium time, and excellent binding ability. Subsequently, the polymers applied as the solid-phase extraction absorbent was proposed and used for the enrichment and analysis of aristolochic acid I in herbal plants. The result showed that the aristolochic acid I was enriched up to 16 times after analysis by using high-performance liquid chromatography. The good linearity for aristolochic acid I was obtained in the range of 0.1-200 μg/mL (R  = 0.9987). The recovery and precision values were obtained (64.94-77.73%, RSDs% ≤ 0.8%, n = 3) at three spiked concentration levels. This work provided a promising method for selective enrichment, extraction, and purification of aristolochic acid I from complex herbal plants.