Cationic polyelectrolyte copolymer modified polyurethane foam for flow injection preconcentration and separation of trace amounts of β-lactam antibiotics

► Novel solid phase sorbent for selective preconcentration of β-lactam antibiotics. ► Improved limit of detection (compared to previous work [1]). ► Improved enrichment factor. ► Isocratic separation of studies antibiotics. ► Successful application to real samples with good recovery and precision.