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Updated: Jun 26, 2026

Measurement of the Potential Rates of Dissimilatory Nitrate Reduction to Ammonium Based on 14NH4+/15NH4+ Analyses via Sequential Conversion to N2O
Published on: October 7, 2020
Amperometric determination of cyanides at the low ppb level by automated preconcentration based on gas diffusion
Constantinos K Zacharis1, Paraskevas D Tzanavaras, Anastasios N Voulgaropoulos
1Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
Abstract:
A simple, sensitive method for determining free cyanides is described. The assay is based on automated gas diffusion of the analyte using sequential injection analysis (SIA) coupled to amperometric detection on a silver working electrode. The effects of varying several parameters affecting the analytical procedure (including the flow rates of the donor and acceptor streams, the concentrations of the reagents and the sample volumes) were studied. The validity and quality of the method were also assessed, by examining its linearity, limits of detection and quantitation, precision, selectivity to potentially interfering substances. Its sensitivity can be enhanced by applying a simple preconcentration step, following which limits of detection were found to be 0.05-0.12 microgL(-1). Application of the proposed assay to the analysis of tap, mineral and table water samples spiked at concentrations ranging from 1 to 10 microgL(-1) CN(-), yielded satisfactory recoveries (88-112%).
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