Synthesis and characterization of molecularly imprinted polymer embedded composite cryogel discs: application for the selective extraction of cypermethrins from aqueous samples prior to GC-MS analysis

摘要

Molecularly imprinted particles embedded composite cryogel discs specific for alpha-cypermethrin and beta-cypermethrin were prepared. Two different types of imprinted particles were embedded into cryogel to prepare composite cryogels specific for two isomers of cypermethrin simultaneously. Adsorption studies revealed that MIP is extremely selective for alpha-cypermethrin and beta-cypermethrin with outstanding adsorption capacity. A sensitive analytical method comprising MISPE coupled with GC-MS has been developed to quantify trace levels of alpha-cypermethrin and beta-cypermethrin in real water matrices. The polymer showed fast kinetics and follows a pseudo-second-order kinetic model very well (R-2 = 0.9999). It shows excellent capacity towards alpha-cypermethrin and beta-cypermethrin with a higher total number of binding sites (N-t - 96 mu mol g(-1) for alpha-cypermethrin and 95 mu mol g(-1) for beta-cypermethrin). The MIP showed selectivity over the homologues of alpha-cypermethrin and beta-cypermethrin with imprinting factor (IF) 11.2, 10.0, 1.04 and 1.20 for alpha-cypermethrin, beta-cypermethrin, deltamethrin and permethrin, respectively. The developed MISPE method followed by GC-MS enhanced the sensitivity and selectivity of the assay. This method was successfully applied to samples of lake water for the determination of alpha-cypermethrin and beta-cypermethrin simultaneously. Moreover, the synthesized MIP can be easily regenerated and repeatedly used without loss of efficiency.