Highly selective water-compatible molecularly imprinted polymers for benzophenone-4

Abstract

Molecularly imprinting technology was applied for preparing selective sorbents for benzophenone-4 (BP4), an organic UV filter used in sunscreens and cosmetics. Several imprinted polymers were prepared by bulk polymerization, using BP4 as template. Combination of stability (mechanical and chemical), selectivity and robustness of imprinted polymers with BP4 properties, resulted in successful imprinting process (imprinting factors in range 1.05-2.60). Prepared polymers were characterized by infrared spectroscopy, elemental analysis, conductometric titrations and nitrogen physisorption at 77 K. Adsorption capacities and selectivity towards 7 other organic UV filters (benzophenone-3, benzophenone-8, homosalate, butyl methoxydiben-zoylmethane, ethyl hexyl salicylate, ethyl hexyl p-dimethylamino benzoate and ethyl hexyl p-methoxycinnamate) were determined, proving high adsorption capacity and high selectivity for BP4 binding. Highest adsorption capacity had 4-vinyl pyridine/ethylene glycol dimethacrylate co-polymer prepared in dimethyl sulfoxide (1.108 mmol g-1). Imprinted polymer with highest binding capacity was applied to solid phase extraction of BP4 from aqueous solutions with 98.5 % efficiency.