Restricted access membrane roll with functionalized silica nanoparticles cross-linked by hydrophilic polymer chains...

Evodiamine and other indole alkaloids are the main active constituents in Evodiae Fructus (EF), which is widely applied in traditional Chinese medicine. Recently, the toxic side effects of EF caused by the alkaloid evodiamine have gradually attracted the attention of researchers. In this regard, the rapid and accurate detection of these alkaloids in biological body fluids has become a challenging task. Therefore, it has become a priority that the rapid and efficient extraction of evodiamine etc. alkaloids from blood sample. In this research, a novel method was proposed to prepare the restricted access (RA) membrane with the hydrophobic functional silica nanoparticles cross-linked on the surface by hydrophilic poly-hydroxyethyl methacrylate (p-HEMA). The poly-HEMA chains played the role of protein exclusion and the functional nanoparticles played the role of hydrophobic adsorbent. The RA membrane was wound into a roll shape and inserted into a 1 mL medical syringe to assemble a portable SPE device, named as SRAMR-SPE, for the direct and simultaneous extraction of evodiamine (EVO), rutecarpine (RUT) and dehydroevodiamine (DHE) in rat plasma after a simple dilution with PBS. The prepared functional nanoparticles and RA membrane were characterized by Fourier transform infrared (FT-IR) spectrometer, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), respectively. HPLC-UV analysis was used to investigate the extraction performance of SRAMR. An associated SRAMR-SPE-HPLC method was constructed and applied to the detection of real rat plasma after the method validation for the verification of the reliability and applicability of the SRAMR-SPE. The experimental results showed that the RA membrane roll (RAMR) had a good ability to exclude plasma proteins and adsorb analytes with multiple reusability. For 3 consecutive cycles of SRAMR-SPE processes, the extraction recoveries of three components at three concentration levels were determined as follows: DHE 93.1-95.1 %, EVO 88.8-91.6 % and RUT 93.6-95.6 %, and the absolute recoveries of the entire SRAMR-SPE-HPLC-UV method were separately as follows: DHE 90.3-92.3 %, EVO 86.2-90.9 %, RUT 91.8-96.4 %. The linear ranges were detected as follows: 0.0600-6.00 μg mL^-1 (DHE), 0.105-5.65 μg mL^-1 (EVO) and 0.0632-6.32 μg mL^-1 (RUT).