利用重氮化反应构建比率型电分析方法测定亚硝酸盐  

A Ratiometric Electroanalytical Method Based on Diazotization Reaction for Detection of Nitrite

作　　者：牛湘衡 汪梦珠[2] 胡盼旺 刘邦祥 NIU Xiang-Heng;WANG Meng-Zhu;HU Pan-Wang;LIU Bang-Xiang(Key Laboratory of Functional Molecular Solids,Ministry of Education,Anhui Normal University,Wuhu 241002,China;Institute of Green Chemistry and Chemical Technology,Jiangsu University,Zhenjiang 212013,China)

机构地区：[1]安徽师范大学功能分子固体教育部重点实验室,芜湖241002 [2]江苏大学绿色化学与化工技术研究院,镇江212013

出　　处：《分析化学》2022年第6期869-877,共9页Chinese Journal of Analytical Chemistry

基　　金：功能分子固体教育部重点实验室开放课题项目(No.FMS202001);国家自然科学基金项目(No.21605061)资助。

摘　　要：食品和水中过量的亚硝酸盐(Nitrite)会对人体健康和环境造成诸多危害,因此开发可靠、便捷、低成本的亚硝酸盐检测方法十分重要。本研究采用邻苯二胺(o-Phenylenediamine, OPD)作为探针,基于重氮化反应开发了一种便捷的比率型电分析方法,利用未修饰的丝网印刷电极(Screen-printed electrode, SPE)实现了对亚硝酸盐的高性能检测。OPD探针可在较低电位处产生一个氧化信号,亚硝酸盐可在较高电位处产生另一个氧化信号。当OPD与亚硝酸盐共存时,两者在酸性环境中会发生重氮化反应。随着亚硝酸盐浓度增大,其自身氧化信号增强,而游离的OPD因重氮化反应消耗而减少,导致此探针的氧化信号减弱,基于此实现了比率型电化学测量。本方法对亚硝酸盐的线性检测范围为10~300μmol/L,检出限(S/N=3)为4.7μmol/L,可对环境水样和腌酸水中的目标物进行准确测定。本方法的灵敏度和准确性优良,抗干扰能力强,操作简便,成本低廉,具有广阔的应用前景。Excessive nitrite in food and water can cause many hazards to human health and the environment, therefore, it is very important to develop reliable, convenient and low-cost methods for nitrite detection. In this study, o-phenylenediamine(OPD)was used as a probe to develop a convenient ratiometric electrochemical method to realize high-performance detection of nitrite on bare screen-printed electrodes. The OPD probe could produce an oxidation signal at a low potential, and nitrite could produce another oxidation signal at a high potential. When OPD coexisted with nitrite, a diazotization reaction occurred in the acidic environment. With the increase of nitrite, free OPD decreased due to reaction consumption, resulting in the decreasing oxidation signal of the probe, while the oxidation signal of nitrite was gradually increased. Based on this principle, ratiometric electrochemical measurement of nitrite was achieved with a linear range of 10–300 μmol/L and a detection limit of 4.7 μmol/L. Accurate determination of the target in environmental water and pickle water samples was also demonstrated. The ratiometric electrochemical method with excellent sensitivity and accuracy, strong anti-interference ability, simple operation and low cost showed broad application prospects.

关 键 词：亚硝酸盐 比率型测量 电分析 邻苯二胺 重氮化反应 

分 类 号：X830.2[环境科学与工程—环境工程] O657.1[理学—分析化学] TS207.3[理学—化学]