磁性氧化石墨烯的制备及用于乳制品中邻苯二甲酸酯类塑化剂的测定

Synthesis of Magnetic Graphene Oxide and Its Application in Determination of Phthalate Ester Plasticizers in Dairy Products

以石墨粉为原料成功制备磁性氧化石墨烯(magnetic graphene oxide,Fe3O4/GO),通过傅里叶变换红外光谱、X-射线衍射和拉曼光谱对制备的Fe3O4/GO进行表征。基于Fe3O4/GO的强吸附性和磁性,将Fe3O4/GO作为新型净化剂改进传统QuEChERS方法对乳制品样本进行预处理,结合气相色谱-质谱联用对16种邻苯二甲酸酯(phthalate esters,PAEs)进行分析检测。通过对提取剂种类、净化剂用量进行优化,确定最佳前处理条件。结果表明:待测物在20~1000μg/L具有良好的线性关系,线性相关系数R≥0.9984,检出限为0.5~2.5μg/kg,16种PAEs在50、100、200μg/kg添加水平下的平均加标回收率为85.7%~117.7%,相对标准偏差不高于7.6%。每处理1 g样品需要有机溶剂2 mL,吸附剂155 mg,用时约8 min。该方法简化了传统QuEChERS步骤,除杂效果好,适合乳制品中PAEs的分析测试。

Magnetic graphene oxide(Fe3O4/GO)was successfully prepared from graphite powder and characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD)and Raman spectroscopy(RS).Fe3O4/GO was used as a new purifying agent to improve the traditional method of quick,easy,cheap,effective,rugged,and safe(QuEChERS)for the pretreatment of dairy samples because of its strong adsorption capacity and magnetism.Using the improved pretreatment procedure combined with gas chromatography-mass spectrometry(GC-MS),16 phthalate esters(PAEs)were analyzed.The optimum pretreatment conditions were determined by optimizing the type of extraction agent and the amount of purifying agent.The results showed that the calibration curves for all PAEs had a good linearity in the concentration range of 20–1000μg/L with correlation coefficients(R)≥0.9984.The lowest limits of detection were between 0.5 and 2.5μg/kg.The average recoveries ranged from 85.7%to 117.7%at spiked concentration levels of 50,100 and 200μg/kg,with relative standard deviation(RSD)not exceeding 7.6%.Two milliliters of organic solvent and 155 mg of adsorbent were required for treatment of 1 g sample,which took about 8 min.The method only needs simple pretreatment and has good impurity removal effects and is suitable for the analysis of PAEs in dairy products.