Preparation Of Bisphenol A Molecularly Imprinted Polymer And Its Application In Food Safety Detection

Bisphenol A(BPA)is a kind of environmental hormone,which is widely used in the production and synthesis of plastic and food packaging materials.The long-term use of these plastic packaging materials and their exposure to high temperatures are likely to result in migration of BPA to food or the environment,and cause harm to human reproduction or immune system.Therefore,strict monitoring is needed.In this paper,SPE-HPLC and piezoelectric quartz crystal microbalance sensors based on the molecularly imprinted polymer(MIP)are used to detect BPA respectively.The MIP was prepared using BPA as template molecule,4-vinylpyridine as functional monomer.From the static adsorption experiments,it could be assumed that the MIP had a higher adsorption capacity for the template BPA compared with the NIP.From the kinetic adsorption experiments,binding equilibrium was obtained within 1 h.The selective experimental results showed that MIP had a high selectivity to the template BPA compared with the other three analogues of the BPA.The MIP was used as a solid phase extraction adsorbent for separation and enrichment of BPA,and it was detected by liquid chromatography.Under the optimum conditions,the minimum detection limit of BPA was 0.047 ?g L-1,and its linear range was 0.5-50 ?g L-1(R2 = 0.9993).The relative standard deviation(RSD)for nine parallel determinations was less than 4.74%.In order to verify the practicability of the established method,three samples of mineral water,tap water and lake water were analyzed and tested.The results showed that the contents of BPA in three kinds of water samples were 0.17 ?g L-1,1.37 ?g L-1 and 8.16 ?g L-1 respectively.The recovery range of the three samples was 88.8%-102.8%.The MIP was used as sensitive identification material to fix on the surface of quartz crystal to construct a QCM sensor for the specific recognition of BPA.The results showed that the sensor had strong adsorption capacity,short adsorption equilibrium time and excellent selectivity for BPA.Under optimum conditions,the detection limit of the sensor was 1.404 ?g L-1 within a linear concentration range of 2.5-60 ?g L-1(R2 = 0.9938).In addition,the sensor was continuously repeated 5 times,with a relative standard deviation of 4.01%,indicating that it had good regeneration performance,which provided convenience for practical detection.In order to verify the practicability of the method,three samples of mineral water,milk and compound fruit and vegetable drinks were analyzed and tested.Among them,BPA was not detected in mineral water and beverages,but the content of BPA in milk was 5.47?g L-1.The recovery rates of mineral water,beverages and milk were 88.2%-97.2%(RSD<6.7%),87.0%-102.9%(RSD<9.9%)and 86.0%-98.9%(RSD<8.8%),respectively.Moreover,the results of QCM sensor had high consistency(R2 =0.9841)with the results of the SPE-HPLC method,indicating that the sensor could be used to detect trace BPA in foods.