氮硫掺杂石墨烯量子点电化学发光猝灭法测定明矾石中汞  

Determination of mercury in alunite by electrochemical luminescence quenching method based on nitrogen and sulfur co-doped graphene quantum dots

作　　者：张效伟[1] ZHANG Xiaowei(School of Science,Qingdao Technological University,Qingdao 266033,China)

机构地区：[1]青岛理工大学理学院,山东青岛266033

出　　处：《冶金分析》2021年第11期57-62,共6页Metallurgical Analysis

基　　金：国家自然科学基金项目(51975305);山东省教育厅重点项目(Z2020046);山东省教育科学研究项目(2020ZC289)。

摘　　要：通过水热法合成了具有良好水溶性和光学性能的氮硫掺杂石墨烯量子点(NS-GQDs),并基于Hg^(2+)能够使NS-GQDs的电化学发光(ECL)信号发生猝灭的原理,建立了NS-GQDs ECL猝灭法测定汞的方法,并将实验方法应用于明矾石中汞的测定。将NS-GQDs修饰到金电极上作为ECL探针,往检测池中加入Hg^(2+)标准溶液,同时加入pH 7.6的磷酸盐缓冲溶液和50 mmol/L K_(2)S_(2)O_(8)溶液,混合均匀后进行ECL检测。在选定的实验条件下,NS-GQDs ECL信号的猝灭值与Hg^(2+)浓度之间具有良好的线性关系,相关系数为0.9997,线性范围为0.1~220μmol/L,检出限为0.03μmol/L,定量限为0.05μmol/L。将实验方法应用于明矾石矿样品中汞的测定并进行加标回收试验,同时采用原子荧光光谱法(AFS)进行方法对照试验,结果的相对标准偏差(n=6)为2.8%~4.3%,回收率在96%~106%之间;利用t检验法比较实验方法和AFS的测定结果,结果表明,在置信度为95%时,t计为0.33,小于t表(2.776),说明这两种方法测得值之间无显著性差异。The nitrogen and sulfur co-doped graphene quantum dots(NS-GQDs)with good water solubility and optical property were synthesized by hydrothermal method.Based on the electrochemical luminescence(ECL)quenching effect of Hg^(2+) on NS-GQDs,a method for the determination of Hg^(2+)was established based on NS-GQDs ECL quenching.The proposed method was applied for the determination of mercury in alunite.NS-GQDs were modified onto gold electrode and then used as ECL probe.Hg^(2+) standard solution was added into detection cell.Meanwhile,the phosphate buffer solution at pH 7.6 and 50 mmol/L K_(2)S_(2)O_(8) solution were also added.The solution was uniformly mixed for ECL detection.Under the selected experimental conditions,the ECL quenching value of NS-GQDs showed good linear relationship with Hg^(2+) concentration.The linear correlation coefficient was 0.9997.The linear range was 0.1-220μmol/L.The limit of detection was 0.03μmol/L,and the limit of quantification was 0.05μmol/L.The proposed method was applied to the determination of mercury in alunite ore sample.Moreover,the standard addition recovery tests were conducted.Meanwhile,atomic fluorescence spectrometry(AFS)was selected for check experiments.The relative standard deviations(RSD,n=6)of determination results were between 2.8% and 4.3%.The recoveries were between 96% and 106%.The t test method was used to compare the determination results of experimental method and AFS.The results showed that|ttest|was 0.33 at confidence interval of 95%,which was less than ttable of 2.776.It was indicated that there was no significant difference between the measurement results of two methods.

关 键 词：氮硫掺杂石墨烯量子点(NS-GQDs) 电化学发光(ECL) 汞 明矾石 

分 类 号：O655.25[理学—分析化学] O657.1[理学—化学]