Lucas Simone Bernardino, Duarte Lucas Mattos, Rezende Kariolanda Cristina Andrade, Coltro Wendell Karlos Tomazelli
Instituto de Química, Universidade Federal de Goiás, Goiânia 74690-900, GO, Brazil.
Instituto de Química, Departamento de Química Analítica, Universidade Federal Fluminense, Niterói 24020-141, RJ, Brazil.
Micromachines (Basel). 2022 Oct 14;13(10):1736. doi: 10.3390/mi13101736.
Nitrite is considered an important target analyte for environmental monitoring. In water resources, nitrite is the result of the nitrogen cycle and the leaching processes of pesticides based on nitrogenous compounds. A high concentration of nitrite can be associated with intoxication processes and metabolic disorders in humans. The present study describes the development of a portable analytical methodology based on microchip electrophoresis coupled with amperometric detection for the determination of nitrite in environmental water samples. Electrophoretic and detection conditions were optimized, and the best separations were achieved within 60 s by employing a mixture of 30 mmol L lactic acid and 15 mmol L histidine (pH = 3.8) as a running buffer applying 0.7 V to the working electrode ( Pt) for amperometric measurements. The developed methodology revealed a satisfactory linear behavior in the concentration range between 20 and 80 μmolL (R = 0.999) with a limit of detection of 1.3 μmolL. The nitrite concentration was determined in five water samples and the achieved values ranged from (28.7 ± 1.6) to (67.1 ± 0.5) µmol L. The data showed that using the proposed methodology revealed satisfactory recovery values (83.5-103.8%) and is in good agreement with the reference technique. Due to its low sample consumption, portability potential, high analytical frequency, and instrumental simplicity, the developed methodology may be considered a promising strategy to monitor and quantitatively determine nitrite in environmental samples.
亚硝酸盐被认为是环境监测的重要目标分析物。在水资源中，亚硝酸盐是氮循环以及含氮化合物农药淋溶过程的产物。高浓度的亚硝酸盐可能与人体中毒过程和代谢紊乱有关。本研究描述了一种基于微芯片电泳与安培检测联用的便携式分析方法的开发，用于测定环境水样中的亚硝酸盐。对电泳和检测条件进行了优化，通过使用30 mmol/L乳酸和15 mmol/L组氨酸（pH = 3.8）的混合物作为运行缓冲液，在工作电极（铂）上施加0.7 V进行安培测量，在60秒内实现了最佳分离。所开发的方法在20至80 μmol/L的浓度范围内呈现出令人满意的线性行为（R = 0.999），检测限为1.3 μmol/L。测定了五个水样中的亚硝酸盐浓度，所得值范围为（28.7 ± 1.6）至（67.1 ± 0.5）µmol/L。数据表明，使用所提出的方法显示出令人满意的回收率（83.5 - 103.8%），并且与参考技术高度一致。由于其低样品消耗、便携潜力、高分析频率和仪器简单性，所开发的方法可被视为监测和定量测定环境样品中亚硝酸盐的一种有前景的策略。
