3.4.2. ComparisonofselectiveextractionofBPAamongC18-SPE, MIP-SPE and NMIP-SPE
The selective extraction of BPA from BPA and its three struc- tural analogues BiP, BP and TBBPA were studied. From Fig. 6, we could find that only BPA was selectively retained on the MIP-SPE column with an almost 100% recovery. C18-SPE column showed no retaining selectivity for BPA owing to BPA and its structural analogues having almost 100% recoveries except TBBPA. BPA and its structural analogues were all poorly retained on the NMIP-SPE column with low recoveries less than 60%. So, BPA-imprinted sor- bent exhibited high selectivity and molecular recognition function. Even if the concentration of each analogue was 3 times that of BPA, the average recovery of BPA was about 100%. This demonstrated that the BPA-imprinted sorbent possessed an adequate ability of anti-interferences.