Enantioselective separation of (±)-epinephrine by chiral acidic molecularly imprinted polymer

In this study, we look into how poly[(4-styrenesulfonic acid)-co-(4-vinylpyridine)] crosslinked with divinylbenzene can be used as a copolymeric material to effectively recognize l-epinephrine (L-EP) and chirally separate (±)-EP. It was first possible to synthesize and analyze L-EP-styrene-4-sulfonamide (L-EP-SSA). The resulting chiral sulfonamide was used to copolymerize with a 4-vinylpyridine–divinylbenzene mixture. The integrated L-EP species were removed by heating the polymer materials under strong alkaline conditions to degrade the sulfonamide links, followed by acidification in HCl solution. The imprinted L-EP-IP materials were analyzed using Fourier transform infrared spectroscopy and scanning electron microscopy. The produced L-EP-IP displayed selectivity characteristics indicative of an affinity for L-EP almost eleven times higher than that for d-epinephrine (D-EP). At a pH of 7, Langmuir adsorption experiments demonstrated a maximal capacity of 165 mg g⁻¹. Following optical separation by means of a column method, enantiomeric excess levels of L- and D-EP in the initial feeding and subsequent recovering solutions were calculated to be 93% and 80%, respectively. © 2024 Society of Industrial Chemistry.