荧光试纸技术可视化定量检测食品中的乙二胺四乙酸

Visual quantitative determination of ethylenediamine tetraacetic acid in food by fluorescent dipstick technique

目的建立荧光试纸技术对食品中乙二胺四乙酸(editic acid,EDTA)进行可视化定量检测的方法。方法以豌豆荚为原料,采用水热法合成蓝色荧光碳量子点(carbon quantum dots,CQDs),利用透射电镜(transmission electron microscope,TEM)、X射线衍射仪(X-ray diffractomer,XRD)、X射线光电子能谱仪(X-ray photoelectron spectroscopy,XPS)和傅里叶变换红外光谱仪(Fourier transform infrared spectrometer,FTIR)对制备的CQDs的形貌及表面结构进行表征;向豌豆荚碳量子点溶液中加入铜离子(Cu^(2+)),使蓝色荧光淬灭,将CQDs-Cu^(2+)溶液吸附于滤纸上,制得EDTA荧光检测试纸。结果EDTA能使CQDs-Cu^(2+)体系淬灭的荧光恢复,在20~120μmol/L范围内与CQDs-Cu^(2+)荧光恢复强度呈现较好的线性关系,检出限为6.29μmol/L,回收率为98.73%~99.40%。结论该试纸可用于定量检测食品中EDTA的含量,为EDTA的检测提供更加简便、直观的方法。

Objective To establish a visual and quantitative method for the determination of editic acid(EDTA)in food by fluorescence dipstick technique.Methods Blue fluorescent carbon quantum dots(CQDs)were synthesized from pea pod by hydrothermal method.The morphology and surface structure of the prepared CQDs were characterized by transmission electron microscopy(TEM),X-ray diffractomer(XRD),X-ray photoelectron spectroscopy(XPS)and Fourier transform infrared spectroscopy(FTIR).Copper ion(Cu^(2+))was added to pea pod carbon quantum dot solution to quench the blue fluorescence.CQDs-Cu^(2+)solution was adsorbed on the filter paper to prepare EDTA detection fluorescence test paper.Results EDTA could restore the quenched fluorescence of CQDS-Cu^(2+)system,there was a good linear relationship with the fluorescence recovery intensity of CQDs-Cu^(2+)in the range of 20‒120μmol/L,the limit of detection was 6.29μmol/L,and the recovery rates were 98.73%‒99.40%.Conclusion The test paper can be used to quantitatively detect the content of EDTA in food and provide a more simple and intuitive detection method for the detection of EDTA.