Improving the Determination of Celecoxib in Body Fluids and Pharmaceuticals by a New Selective and Thermosensitive Molecularly Imprinted Poly(vinylidene fluoride) Membrane
Molecularly imprinted membranes that demonstrated high selectivity for celecoxib were synthesized using N-vinylcaprolactam and 2-Hydroxyethyl methacrylate functional monomers, crosslinking with the ethylene glycol dimethacrylate and, 2,2′-azobisisobutyronitrile as the initiator. The obtained polymeric membrane was characterized using attenuated total reflection Fourier transmission infrared spectroscopy technique and scanning electron microscopy and was employed as a solid-phase extraction medium for extraction of celecoxib from biological and pharmaceutical samples. The effects of pH, contact time on the sorption, capacity of polymeric sorbent, and interfering drugs were investigated as critical analytical parameters. Several models, including Longmuir, Temkin, Freundlich, and Redlich-Peterson, were used to study the equilibrium adsorption data of celecoxib on the polymeric sorbent. The developed method was utilized to determine the concentration of celecoxib in pharmaceutical and biological samples. The results of extraction recoveries for celecoxib in urine, plasma, and drug matrix were more than 93.3%, 90.7%, and 87.2%, respectively. The analytical determination revealed that the limit of detection and limit of quantification of celecoxib were 0.9 and 3.0 ng mL-1, respectively. Accordingly, the experiments indicated that the proposed molecularly imprinted membranes showed high selectivity to celecoxib and can be used for sensing the presence of celecoxib in biological samples.