Voltammetric determination of organic nitrogen compounds in environmental samples using carbon paste electrode modified with activated carbon

• Published in: Microchemical journal 2019-07, Vol.148, p.66-72
• Main Authors: Teixeira, Meryene de C., Felix, Fabiana S., Thomasi, Sérgio S., Magriotis, Zuy M., da Silva, Josiane M., Okumura, Leonardo L., Saczk, Adelir A.
• Format: Article
• Language: English
• Subjects: Differential-pulse voltammetry; Fuels; Pyridine; Quinoline; Square-wave voltammetry; Textile effluents
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2019.04.038

A quick and simple procedure is described to determine pyridine and quinoline using voltammetric methods and carbon paste electrodes modified with activated carbon in the proportion of 50:20:30 w/w graphite:activated carbon:silicon. Studies with cyclic voltammetry indicated that reduction of organic nitrogen molecules is irreversible in ammonium chloride solution acidified to pH 2.5 with Britton-Robinson buffer. Under the best optimum conditions for the differential pulse voltammetry for pyridine and square wave voltammetry for quinoline, the analytical curve was linear from 1.0 × 10−4 to 9.0 × 10−7 mol L−1 for both analytes with limits of detection of approximately 2.0 × 10−7 mol L−1 and limits of quantification of approximately 7.0 × 10−7 mol L−1. The proposed methods were successfully applied to determine pyridine and quinoline in samples of textile effluents and fuel with minimum sample treatment. •The molecules pyridine and quinoline are molecules model for studies in monitoring of environmental contamination.•The proposed methodology was used for quantification of pyridine and quinoline in textile effluents and organic matrices.•The EPCM / CA were easy to construct and satisfactory sensitivity for the quantification of pyridine and quinoline molecules.•The proposed method was satisfactory for determination of pyridine and quinoline as required by current legislation.