Abstract
A more sensitive flow injection preconcentration method has been developed for the determination of four β-lactam antibiotics (BLAs) namely cefaclor, cefotaxime, amoxicillin and ampicillin in urine, pharmaceuticals and milk. A mini-column packed with PUF functionalized with the cationic polyelectrolyte, poly(N-chloranil N,N,N′,N′-tetramethylethylene diammonium dichloride) PCTDD, was utilized for selective preconcentration. The detection limits with this method were 3.3, 3.8, 5.1 and 7.0ngmL−1 and enrichment factors were 38, 21, 39, and 36 for cefaclor, cefotaxime, amoxicillin and ampicillin, respectively with a sample throughput of 12h−1 for all BLAs. Moreover, the BLAs were successfully separated by isocratic elution using a micellar mobile phase. Application of the method developed has resulted in recovery values in the range 95%–109% (RSD≤8.7), 83%–99% (RSD≤9.7) and 91%–103% (RSD≤4.0) for urine, pharmaceuticals and milk samples, respectively.
► 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.