Electrochemical Detection of Ammonia in Aqueous Solution using Fluorescamine: A Comparison of Fluorometric Versus Voltammetric Analysis

Authors

Panchompoo Janjira, Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom;
G. Compton Richard, Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom;Follow

Corresponding Author

G. Compton Richard(richard.compton@chem.ox.ac.uk)

Abstract

Fluorescamine is a non-fluorescent reagent widely used for the quantitative determination of primary amines by fluorescence spectroscopy as it reacts readily with primary amines to form a fluorescent product. In this work, a new sensitive voltammetric method for the detection of ammonia in aqueous solution by the reaction with fluorescamine has been developed. First, the electrochemical behaviour of fluorescamine in the absence and presence of ammonia was investigated in 0.1 mol L^-1 borate buffer solution (pH 9.0) by cyclic voltammetry using a glassy carbon (GC) electrode. As for fluorescamine itself, a well-defined irreversible oxidation peak could be observed at ca. 0.70 V vs. SCE. When ammonia was added to the fluorescamine solution, another irreversible oxditaion peak corresponding to the oxidation of the reaction product formed between fluorescamine and ammonia could be observed at ca. 0.46 V vs. SCE. Upon the addition of ammonia, the oxidation peak of fluorescamine became smaller while the oxidation peak of the reaction product formed increased in height, due to the stoichiometric chemical consumption of fluorescamine by ammonia and the formation of the product during the reaction, respectively. These two anodic peaks corresponding to the oxidation of fluorescamine and its fluorescent product formed were then used for the quantitative detection of ammonia, explored by square wave voltammetry and by fluorescence spectroscopy. The square wave voltammetric response of the reaction product formed showed a linear response over ammonia concentration range of 0 to 60 μmol L^-1. The limits of detection (LOD) was found to be 0.71 μmol L^-1 and 3.17 μmol L^-1 determined based upon Signal/Noise (S/N) = 3 and 3σ, respectively. These limits of detection are similar to those obtained with the fluorometric method.

Graphical Abstract

Keywords

electrochemical detection, cyclic voltammetry, square wave voltammetry, fluorescence spectroscopy, ammonia, fluorescamine

DOI Link

https://doi.org/10.61558/2993-074X.2614

Publication Date

2012-10-28

Online Available Date

2012-08-30

Revised Date

2012-08-27

Received Date

2012-06-26

Recommended Citation

Panchompoo Janjira, G. Compton Richard. Electrochemical Detection of Ammonia in Aqueous Solution using Fluorescamine: A Comparison of Fluorometric Versus Voltammetric Analysis[J]. Journal of Electrochemistry, 2012 , 18(5): Article 6.
DOI: 10.61558/2993-074X.2614
Available at: https://jelectrochem.xmu.edu.cn/journal/vol18/iss5/6