氧化石墨烯-邻苯二甲酸二(2-乙基己)酯表面分子印迹吸附剂的合成及应用

Synthesis and application of a surface molecularly imprinted adsorbent for di(2-ethylhexyl)phthalate base on graphite oxide

合成了以纳米材料氧化石墨烯为载体的表面分子印迹固相萃取材料,建立了分子印迹萃取联用高效液相色谱法检测牛奶塑料包装袋中的塑化剂邻苯二甲酸二(2-乙基己)酯(DEHP)残留的方法。以氧化石墨烯为基质、DEHP为模板分子、甲基丙烯酸为功能单体、 N,N -二甲基甲酰胺为溶剂,通过沉淀聚合法合成表面分子印迹材料,优化了合成条件并对产品进行红外光谱、透射电镜表征。对产品的吸附性能(包括选择性、吸附平衡时间、吸附容量、重复使用率等)进行测定。在最优萃取条件下对牛奶包装袋提取液中DEHP进行选择性富集,通过高效液相色谱-紫外法检测,线性范围为0.5~50 mg/L ,检出限为0.03 mg/L ,定量限为0.1 mg/L 。3种加标浓度下回收率为81.6%~92.4%,相对标准偏差(RSDs)小于7%。结果表明,该方法能够应用于实际样品中DEHP分析。

A molecularly imprinted polymer (MIP) base on the surface of graphite oxide (GO) has been developed for the selective recognition of di(2-ethylhexyl)phthalate (DEHP), and applied for the extraction of DEHP in a milk bag sample, with detection by high-performance liquid chromatography. The surface-molecularly imprinted material was prepared by precipitation polymerization in N,N -dimethylformamide (DMF) solvent, using GO as the supporting material, DEHP as the template molecule, and methacrylic acid (MAA) as the functional monomer;the synthesis conditions were also optimized. The obtained GO-MAA-MIP was characterized by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM). The adsorption properties of the product were evaluated by adsorption experiments , including adsorption isotherms, kinetics, selectivity, saturated adsorption capacity , adsorption equilibrium time, and reusability. Under optimized conditions, DEHP was effectively extracted in the real sample (milk bag) and detected by HPLC. Linearity was obtained with a correlation coefficient ( R 2) of 0.997 9 in a linear range of 0.5-50 mg/L . The limits of detection and quantitation were 0.03 mg/L and 0.1 mg/L , respectively. The average recoveries of the spiked samples at three concentration levels of DEHP ranged from 81.6% to 92.4% with relative standard deviations (RSDs) less than 7%. The results indicated that the proposed GO-MAA-MIP-SPE (solid phase extraction) protocol with HPLC-UV detection could be applied for the selective analysis of DEHP in real samples.