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Voltammetric determination of nitrate with a modified carbon paste electrode
Author(s) -
Neuhold Christian,
Kalcher Kurt,
Diewald Wolfgang,
Cai Xiaohua,
Raber Georg
Publication year - 1994
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.1140060309
Subject(s) - nitrate , chemistry , amberlite , inorganic chemistry , electrode , voltammetry , differential pulse voltammetry , hydrochloric acid , cyclic voltammetry , carbon fibers , electrochemistry , materials science , adsorption , organic chemistry , composite material , composite number
A method for the voltammetric determination of nitrate in drinking water is presented. Nitrate exerts a catalytic effect on the reduction and reoxidation of thallium (1 ↔ 0) in cyclic and differential pulse voltammetry, leading to a peak enhancement. Nitrate can be preconcentrated together with tetrachlorothallate(III) from hydrochloric acid solutions onto a carbon paste electrode modified with a liquid anion exchanger. (Amberlite LA2) under open circuit conditions. After reduction of the Tl(III) to Tl(0) at the electrode surface at a potential of −1.2 V (vs. SCE), the increase of the reoxidation current of Tl(III) to TI(I) by nitrate is exploited for analytical purposes. Linearity between current and concentration exists for 0.5 to 60 μg · mL −1 nitrate when applying anodic differential pulse vokammetry. Mechanical regeneration of the electrode surface is necessary after each measurement. The interference of other anions and the influence of methodical parameters are invistigated. The applicability of this method for the determination of nitrate in drinking wat concise overview on the the electroanalytical techniques for the Quantitative determination of nitrate is also presented.