Analytical Chemistry, 07/1985, Vol.57(8), pp.1541-1546
Dual-electrode thin-layer amperometric detectors have been shown to improve the selectivity and sensitivity of electrochemical detectors for liquid chromatography. Most applications have monitored the signal at each electrode individually. This report demonstrates several advantages that can be achieved by recording the difference in the response of the two electrodes. In the parallel adjacent configuration, selectivity can be increased by monitoring a small potential window using this difference mode. In the series configuration, sensitivity can be increased for chemically reversible species through redox cycling. Alternatively, base line interferences can be diminished by equipotential operation in the series configuration. Improved signal-to-noise ratios can be obtained in both the parallel-adjacent and series configurations from attenuation of base line interferences. The determination of phenolic acids in commercial beer samples is used to demonstrate these techniques. 12 references, 9 figures, 3 tables.
Inorganic, Organic, Physical And Analytical Chemistry ; Environmental Sciences ; Beverages ; Quantitative Chemical Analysis ; Organic Acids ; Amperometry ; Sensitivity ; Thin-Layer Chromatography ; Phenol ; Alcohols ; Electrochemistry ; Electrodes ; Experimental Data ; Redox Reactions ; Signal-To-Noise Ratio ; Trace Amounts ; Aromatics ; Chemical Analysis ; Chemical Reactions ; Chemistry ; Chromatography ; Data ; Food ; Hydroxy Compounds ; Information ; Numerical Data ; Organic Compounds ; Phenols ; Separation Processes ; Titration ; 400102 - Chemical & Spectral Procedures ; 520200 - Environment, Aquatic- Chemicals Monitoring & Transport- (-1989) ; 400301 - Organic Chemistry- Chemical & Physicochemical Properties- (-1987) ; 400400 - Electrochemistry ; Environmental Sciences ; Chemistry;