Molecularly imprinted solid phase extraction-pulsed elution for rapid screening and determination of cephalexin in alpha-aminocephalosporin antibiotics

The molecular recognition properties of cephalexin molecularly imprinted polymer (MIP) in various organic solvents were investigated. A molecularly imprinted solid phase extraction (MISPE) method was developed for rapid screening and determination of cephalexin in α-aminocephalosporin antibiotics. Cephalexin MIP particles were packed into a micro-column (i. d. 0.8 mm x 50 mm) for selective solid phase extraction (SPE) of CFL.; The method was further developed by introducing a Quattro triple quadrupole mass spectrometer to substitute the UV detector. Elution of cephalexin (m/z 348) was quantified using sulindac (m/z 357) as an internal standard to correct for signal variations, by recording the peak intensity ratio of cephalexin/sulindac versus the mass of CFL isolated in MISPE. The mass spectrometer was programmed in the positive electrospray mode, coupled with the selected ion recording (SIR) function, to improve the detection and quantification of the molecular ions of cephalexin and sulindac. (Abstract shortened by UMI.)...