Preparation Of Dummy Template Imprinted Polymers At Surface Of Silica Submicroparticles For The Selective Extraction Of Trace Bisphenol A From Water Samples

Bisphenol A (BPA) is a kind of environmental hormones, which would make the disorder of estrogenic hormone secretion even at trace concentration. Because of the wide availability of BPA in our environment, it is necessary to monitor trace BPA in environmental samples. In this study, we prepared molecularly imprinted polymers (MIPs) for BPA at the surface of silica submicroparticles by using dummy templates, and the polymers were used as sorbent materials applied to the solid-phase extraction coupled with HPLC/UV to determine the trace amounts of BPA in environment water samples.Molecularly imprinted polymers have attracted considerable attention for being easy to prepare and being able to adsorb the template molecules selectively from a mixture of chemical species. We prepared molecularly imprinted polymers for BPA at the surface of silica submicroparticles by using surface molecular imprinting technique. Analogues of BPA, namely 4, 4'-dihydroxybiphenyl (DDBP) and 3, 3', 5, 5'-tetrabromobisphenol A (TBBPA) , were used as the dummy templates instead of BPA, to avoid the leakage of trace amount of the target analyte (BPA). The resulting dummy molecularly imprinted polymers (DMIPs) showed large sorption capacity and fast binding kinetics for BPA. The maximal sorption capacity was up to 958μmol g-1, and it only took 40 min for DMIPs to achieve the sorption equilibrium. The DMIPs also showed highly selective recognition ability. Compared with the analogues of BPA, TBBPA, p-tert-butylphenol (BP) and estradiol (ED), the recognition ability of DMIPs for BPA was six times that for TBBPA, twenty times that for ED and above forty times that for BP.In addition, the DMIPs were applied to the solid-phase extraction (SPE) and the comparison between the DMIPs SPE and C18 SPE was made. It was found that DMIP-SPE columns were superior to the C18 SPE columns. In the breakthrough volume test, there was 110% of BPA recovered for DMIP-SPE columns even if 1 L of BPA standard solution was loaded. It indicated that DMIPs prepared could be used as SPE sorbents for extraction of trace BPA from environmental samples with high load volumes. Finally, the DMIP was successfully applied to solid-phase extraction coupled with HPLC/UV to determine the trace BPA in real water samples. The calibration graph of the analytical method was linear with a correlation coefficient higher than 0.999 in the concentration range of 0.0760–0.912 ng mL-1 of BPA. The limit of detection was 15.2 pg mL-1 (S/N = 3). Recoveries were in the range of 92.9–102% with relative standard deviation (RSD) less than 11%. The trace amounts of BPA in tap water, drinking water, rain and leachate of one-off tableware were determined by the method built, and the satisfactory results were obtained.