The Synthesis of Molecularly Imprinted Polymers on Microcentrifuge Tube Filters for Solid-Phase Extraction and the HPLC-UV Determination of Andrographolides

Abstract Molecular imprinting-based solid-phase extraction has been in the spotlight to improve recognition selectivity and detection sensitivity of andrographolides. The synthesis of molecularly imprinted polymers on micro centrifuge tube filters for the extraction and the determination of andrographolides were investigated. Molecularly imprinted polymers were synthesized using the photo-polymerization method for the preconcentration of andrographolides (AD) template molecule using 2,2-dimethoxy-2-phenylacetophenone as initiators, the mixture of 1-dodecanol and toluene solvent, 2-hydroxyethyl methacrylate and ethylene glycol dimethacrylate as functional monomers and cross-linked, respectively. The resultant AD molecularly imprinted polymers (AD-MIPs) were characterized using the Fourier-transform infrared spectrum and scanning electron microscopy. The maximum adsorption of AD-MIPs toward the andrographolides was found to be 85%, and could reach binding equilibrium within 60 min. The sample solution was separated by AD-MIP using solid-phase extraction (SPE). Subsequently, the sample solution was analyzed by the high-performance liquid chromatography (HPLC) method. The AD-MIP could be successfully applied to specifically separate and determine the andrographolides from pharmaceutical products and biological fluid samples with relatively high recoveries (102.01–108.61%). The present method is simple, selective, accurate, and provides a promising alternative to traditional SPE sorbents for the extraction and determination of andrographolides in real samples and biological fluid samples.