Costa Daniel J E, Martínez Ana M, Ribeiro Williame F, Bichinho Kátia M, Di Nezio María Susana, Pistonesi Marcelo F, Araujo Mario C U
Universidade Federal da Paraíba, Departamento de Química, Laboratório de Automação e Instrumentação em Química Analítica/Quimiometria, Caixa Postal 5093, CEP 58051-970 João Pessoa, PB, Brazil.
Departamento de Química, Universidad Nacional del Sur, INQUISUR (UNS-CONICET), Av. Alem 1253, B8000CPB Bahía Blanca, Buenos Aires, Argentina.
Talanta. 2016 Jul 1;154:134-40. doi: 10.1016/j.talanta.2016.03.063. Epub 2016 Mar 21.
Tryptamine, a biogenic amine, is an indole derivative with an electrophilic substituent at the C3 position of the pyrrole ring of the indole moiety. The electrochemical oxidation of tryptamine was investigated using glassy carbon electrode (GCE), and focusing on trace level determination in food products by square wave adsorptive stripping voltammetry (SWAdSV). The electrochemical responses of tryptamine were evaluated using differing voltammetric techniques over a wide pH range, a quasi-reversible electron-transfer to redox system represented by coupled peaks P1-P3, and an irreversible reaction for peak P2 were demonstrated. The proton and electron counts associated with the oxidation reactions were estimated. The nature of the mass transfer process was predominantly diffusion-limited for the oxidation process of P1, the most selective and sensitive analytical response (acetate buffer solution pH 5.3), being used for the development of SWAdSV method, under optimum conditions. The excellent response allowed the development of an electroanalytical method with a linear response range of from 4.7-54.5)×10(-)(8)molL(-1), low detection limit (0.8×10(-)(9)molL(-)(1)), and quantification limit (2.7×10(-9)molL(-1)), and acceptable levels of repeatability (3.6%), and reproducibility (3.8%). Tryptamine content was determined in bananas, tomatoes, cheese (mozzarella and gorgonzola), and cold meats (chicken sausage and pepperoni sausage), yielding recoveries above 90%, with excellent analytical performance using simple and low cost instrumentation.
色胺是一种生物胺，是一种吲哚衍生物，在吲哚部分吡咯环的C3位置带有亲电取代基。使用玻碳电极（GCE）研究了色胺的电化学氧化，并通过方波吸附溶出伏安法（SWAdSV）专注于食品中痕量水平的测定。在较宽的pH范围内使用不同的伏安技术评估了色胺的电化学响应，证明了由耦合峰P1 - P3表示的准可逆电子转移到氧化还原系统，以及峰P2的不可逆反应。估计了与氧化反应相关的质子和电子数。对于P1的氧化过程，传质过程的性质主要是扩散限制的，P1是最具选择性和灵敏的分析响应（醋酸盐缓冲溶液pH 5.3），在最佳条件下用于开发SWAdSV方法。出色的响应使得能够开发一种电分析方法，其线性响应范围为（4.7 - 54.5）×10^(-8) molL^(-1)，检测限低（0.8×10^(-9) molL^(-1)），定量限（2.7×10^(-9) molL^(-1)），以及可接受的重复性水平（3.6%）和再现性（3.8%）。测定了香蕉、西红柿、奶酪（马苏里拉奶酪和戈贡佐拉奶酪）和冷肉（鸡肉香肠和意大利辣香肠）中的色胺含量，回收率高于90%，使用简单且低成本的仪器具有出色的分析性能。
