Development of a molecularly imprinted solid phase extraction sorbent for the selective removal of rivastigmine from serum samples

A molecularly imprinted solid-phase extraction (MISPE) sorbent has been developed for the separation of RIV from serum sample. Molecularly imprinted polymer (MIP) was prepared via non-covalent imprinting technique using RIV as a template molecule, methacrylic acid (MAA) as a functional monomer, ethylene glycol dimethacrylate (EGDMA) as a crosslinker, N, N-azobisisobutyronitrile (AIBN) as an initiator, and dimethylsulfoxide (DMSO) as a porogenic solvent. An imprinting factor of 3.4 was achieved for the RIV imprinted MIP. Adsorption behavior of the sorbent followed Langmuir model and reached a maximum adsorption capacity of 20.7 mg/g. Adsorption kinetics was also investigated using pseudo-first and second-order models. MIP and NIP sorbents were dry-packed into solid-phase extraction cartridges and eluates from cartridges were analyzed. Limit of detection and limit of quantification values were 0.635 and 1.92 µg/mL, respectively. Recovery values for the MIP and NIP sorbents were 72.6 and 17.2 %, respectively. Excellent within-day (0.22–1.34 % RSD) and between-day (0.43–1.46 % RSD) precision values were also achieved for the MIP sorbent as well. Our findings prove that the developed MISPE method exhibits high precision and selectivity towards RIV in serum sample containing high number of interfering compounds.