Synthesis of a Novel Molecularly Imprinted Polymer for the Sensitive and Selective Determination of Artemisinin in Urine Samples Based on Solid-Phase Extraction (SPE) and Determination with High-Performance Liquid Chromatography (HPLC)

A novel molecularly imprinted solid-phase extraction method coupled with high-performance liquid chromatography (HPLC) is reported for the sensitive and selective determination of artemisinin in urine samples. Molecularly imprinted polymers were synthesized by free-radical polymerization through a noncovalent imprinting method using artemisinin (template), methacrylic acid (functional monomer), ethylene glycol dimethacrylate (cross-linker), azobisisobutyronitrile (initiator), and acetonitrile (porogen). The adsorption properties of the artemisinin-imprinted polymers obeyed the Langmuir isotherm with 23.9 mg/g maximum adsorption capacity and pseudo-second-order kinetics with an equilibrium adsorption time of 60 min. The prepared artemisinin-imprinted polymers showed high selectivity toward artemisinin and could be used multiple times, at least five, without changes to adsorption capacity. Furthermore, the imprinted and nonimprinted particles were placed into cartridges through dry packing, and eluates collected from cartridges were subjected to high-performance liquid chromatography. The limit of quantification and limit of detection values were 4.5 µg/L and 1.3 µg/L, respectively. The recovery of artemisinin from urine samples varied between 95.7% and 100.0%, and the relative standard deviation was less than 4.0%. The results indicated the prepared sorbent can be used for simple, selective, and sensitive detection of artemisinin from urine by a combination of solid-phase extraction and high-performance liquid chromatography.