Simultaneous Determination of Six Alkaloids in Rat Plasma with On-line SPE–HPLC Using a Homemade Four-Hydrogen Furfuryl-Based Polymer Monolithic Sorbent

Abstract

Abstract A four-hydrogen furfuryl-based polymer monolithic column for solid-phase extraction was prepared via in situ radical polymerization, using tetrahydrofurfuryl methacrylate as the monomer. The monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and nitrogen adsorption–desorption method, showing relatively uniform porous structure with micro-, meso- and macro-pores and a relatively high surface area of 54.99\xa0m 2 \xa0g −1 . Online solid-phase extraction–high-performance liquid chromatography was carried out to quantitatively analyze six alkaloids, including caffeine, hydroxy-α-sanshool, hydroxy-β-sanshool, hydroxy-γ-sanshool, hydroxy-γ-isosanshool and γ-sanshool in rat plasma. The results show that the prepared polymer monolithic sorbent exhibits good clean-up ability for bio-matrix, as well as good extractive ability for the six concerning alkaloids in rat plasma. Method validation shows that the correlation coefficients of the linear regressions are higher than 0.998 and the accuracy represented by spiked recovery ranges in 94.37–100.7%, 99.52–101.1%, 98.93–100.8%, 98.36–101.6%, 99.22–101.2% and 99.86–101.4% for the six alkaloids, respectively, as well as the LOD ranges in 2.10–3.90\xa0ng\xa0mL −1 and the LOQ in 6.35–10.14\xa0ng\xa0mL −1 . Compared to the reference works, the present work is a simple and effective method for online extraction and simultaneous determination of six alkaloids in plasma with high accuracy and low cost. Graphic Abstract