Preparation and characterization of dummy template molecularly imprinted polymers coupled with HPLC for selective extraction of spiked cloprostenol from milk samples

This study was conducted to develop a particular sorbent for the selective extraction of the luteolytic drug cloprostenol from milk samples. Cloprostenol's luteolytic activity has been proved in animals, whereas the production of prostaglandins is discussed extensively in the literature, while extraction of cloprostenol is rarely discussed. The major objective was to get sufficient molecularly imprinted polymers (MIPs) for selective extraction and detection of cloprostenol. After a series of experiment, MIPs and their analogues NIPs, were synthesized. In these experiments, radical polymerization with non-covalent interactions has been used to synthesize MIPs and NIPs. Different parameters to determine the optimization conditions such as solvent volume, cross-linker, and template ratio were studied in various sets to get better possible characteristics of MIPs. The HPLC was used to evaluate the retention capacity which ranges from 68.5% to 94.1%. The mechanism of adsorption was studied by the isothermal assay and kinetic studies. The kinetic studies exhibited a high retention capacity within 20 min of MIPs contact. The percentage of polymer yield ranged from 53.5% to 92.3%. HPLC coupled with a UV detector showed the limit of detection and limit of quantification of 30.5 ng/mL and 86.7 ng/mL, respectively, for the determination of analytes from milk samples. The recovery of cloprostenol for all spiked samples of milk was higher than 91.54%. Furthermore, the studies showed that MIPs are specific in the adsorption of cloprostenol compared to its other structural analogues. The outcomes also showed the significance of cross-linker concentration and the amount of solvent during the process of polymerization. These parameters greatly affect the preorganization of complementary functional groups, meanwhile, it creates specific cavities for the targeted drugs.