摘要
提出了基于铕离子-四环素-草甘膦荧光增强体系结合分子印迹固相萃取测定环境样品中草甘膦残留量的方法。以正硅酸乙酯为溶胶-凝胶功能单体,在pH 1.0的硅溶胶-凝胶体系中制备了草甘膦分子印迹固相萃取膜,用于环境水和土壤样品的前处理。将前处理后的样品溶液与1.5×10^(-2)mol·L^(-1)EuCl_(3)溶液、3.0×10^(-3)mol·L^(-1)四环素溶液和100 mmol·L^(-1)硼酸盐缓冲溶液(pH 10.0)按照一定比例混合,静置反应3 min;以403 nm为激发波长,根据体系在615 nm发射波长处的荧光强度增加值ΔF计算草甘膦的含量。结果表明:在较强碱性条件下,草甘膦的加入使体系在615 nm处的荧光强度显著增强;草甘膦浓度的对数在5.0×10^(-8)~1.5×10^(-4)mol·L^(-1)内与体系ΔF值呈线性关系,检出限(3s/k)为1.0×10^(-8)mol·L^(-1);草铵膦、氨甲基膦酸、常见金属离子以及结构类似的氨基酸等不干扰铕离子-四环素-草甘膦体系的荧光强度,而Fe^(3+)、Hg^(2+)会产生干扰,因此样品前处理过程中加入三乙醇胺进行掩蔽。方法用于实际环境水和土壤样品分析,草甘膦测定值与电化学法测定值基本一致;按照标准加入法对其中一个水样进行回收试验,草甘膦回收率为101%。
A method for the determination of residue of glyphosate in environmental samples based on europium ion-tetracycline-glyphosate fluorescence enhancement system combined with molecular imprinted solid phase extraction was proposed.Using ethyl orthosilicate as sol-gel functional monomer,glyphosate molecular imprinted solid phase extraction membrane was prepared in a silica sol-gel system at pH 1.0 for the pretreatment of environmental water and soil samples.The pretreated sample solution was mixed with 1.5×10^(-2)mol·L^(-1)EuCl_(3)solution,3.0×10^(-3)mol·L^(-1)tetracycline solution and 100 mmol·L^(-1)borate buffer solution(pH 10.0)at a definite ratio,then the mixed solution was reacted for settling 3 min.The content of glyphosate was calculated according to the increase of fluorescence intensity(ΔF value)of the system at emission wavelength of 615 nm,with 403 nm as excitation wavelength.It was shown that the fluorescence intensity of the system at 615 nm was significantly enhanced by the addition of glyphosate under higher alkaline condition,and linear relationship between the logarithm of glyphosate concentration andΔF value of the system was kept in the range of 5.0×10^(-8)-1.5×10^(-4)mol·L^(-1),with detection limit(3s/k)of 1.0×10^(-8)mol·L^(-1).Glyphosate-ammonium,and aminomethylphosphonic acid,common metal ions and amino acids with similar structure did not interfere with the fluorescence intensity of europium ion-tetracycline-glyphosate system,but Fe^(3+)and Hg^(2+)did,so triethanolamine was used during sample pretreatment for masking.The method was applied to analysis of water and soil samples in real environment,and the determined values of glyphosate were basically consistent with those obtained by electrochemical method.Test for recovery was made on the water sample according to the standard addition method,giving the result of 101%.
作者
袁宁
沈晓峰
全红花
曾诚
李明
YUAN Ning;SHEN Xiaofeng;QUAN Honghua;ZENG Cheng;LI Ming(School of Environmental Science and Engineering,Yangzhou University,Yangzhou 225127,China;Yangzhou Customs District,Yangzhou 225100,China)
出处
《理化检验（化学分册）》
CAS
CSCD
北大核心
2024年第1期15-21,共7页
Physical Testing and Chemical Analysis(Part B:Chemical Analysis)
基金
南京海关科技项目(No.2021KJ21)。
关键词
草甘膦
铕离子
四环素
荧光
分子印迹固相萃取
glyphosate
europium ion
tetracycline
fluorescence
molecular imprinted solid phase extraction
