Trace determination of celecoxib in biological samples after preconcentration by Dμ-SPE technique using a magnetized functionalized MOF/nanokeratin composite

Abstract

Listen

Translate article

Partially NH2-functionalized ZIF-7 and nanokeratin extracted from sheep wool were exploited for in-situ synthesis of a new magnetized nanocomposite (magnetized nanokerattin@NH2-ZIF-7; MKNZ). First, the MKNZ properties towards celecoxib (CXB) adsorption was inspected by scrutinizing assessments of equilibrium, thermodynamic, and kinetic aspects. Then, after discovering MKNZ advantages for CXB adsorption and its characterization studies, a selective, sensitive sample preparation procedure was designed for preconcentration of trace CXB amounts using Dμ-SPE (dispersive micro solid phase extraction) technique. Compared with the nanocomposite synthesized without NH2– functionalization, MKNZ exhibited stronger interactions with CXB molecules and a much higher affinity towards their adsorption with a maximal capacity of 61.05 mg/g at pH 6.8 and 25 ℃, revealed by thermodynamic studies. Using ultrasonic-assisted agitation, kinetic and isothermal assessments demonstrated that, even at high levels, MKNZ was capable to adsorb almost the whole drug molecules in a short time (3 min). The devised Dμ-SPE for preconcentrative extraction of CXB was optimized and triumphally exploited for determining trace CXB levels existing in biological samples, i.e., human plasma, breast milk, and urine samples, using high performance liquid chromatography (HPLC) equipped with UV– Visible (UV) detector. Overall, the devised analytical method for CXB was highly beneficial, so that a wide linearity (0.1–10 ng/mL), a low limit of detection (0.03 ng/mL), acceptable intra- and inter–day precisions (RSD ≤ 4.9%; n = 7), and high relative recoveries (>95.25%) were obtained.