University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
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Zeitschrift fur Chemie

  • Publisher: Wiley
  • FAD Code: ZSCH
  • CODEN: ZECEAL
  • ISSN: 0044-2402
  • Abbreviation: Z. Chem.
  • DOI Prefix: 10.1002/ange
  • Language: German
  • Comments: Fulltext from 1887 V1

Citations 11

"HPLC Dual-electrode Electrochemical Detection Of Phenols After Post-column Derivatization"
Z. Chem. 1990 Volume 30, Issue 12 Pages 448-450
Jörg Noack, Jürgen Mattusch, Gerhard Werner

Abstract: A mixture of catechol, resorcinol and quinol in McIlvain buffer solution (pH 2.4) was analyzed by HPLC on a Separon (18.5 µm) reversed-phase column (15 cm x 4 mm). The amperometric detection system consisted of an Ag - AgCl reference electrode, a steel auxiliary electrode and two vitreous-carbon working electrodes. The eluted analyte was first oxidized at the first and then reduced at the second carbon electrode. With applied potentials +1100 and +100 mV, all three isomers gave anodic and cathodic peaks, but at +800 and -100 mV only catechol and quinol were detected. When post-column derivatization by UV irradiation [in a PTFE tube (9.5 m x 0.3 mm) at a flow rate of 0.6 mL s-1] was applied, the sensitivity for catechol and quinol deteriorated to 59% of the value found without derivatization. For resorcinol, however, irradiation caused a sensitivity improvement to 154% (by measurement of the anodic current at +1100 mV) and a decrease in the detection limit to 0.7 pmol.
Phenols HPLC Electrochemical analysis Amperometry Electrode Post-column derivatization Buffer Column Reverse pH Sensitivity Detection limit

"Universal Electrochemical Detector For Flowing Liquids"
Z. Chem. 1990 Volume 30, Issue 11 Pages 419-419
Klaus Bartels

Abstract: The described flow-through cell (for use in, e.g., LC or flow injection analysis) consists of a PTFE block drilled at right-angles with four converging tubular holes to which, by means of interchangeable screw connections, the inlet and outlet tubing and the working and Ag - AgCl reference electrodes are connected. The effective volume of the cell can be altered by the use of electrode mountings of different lengths. The cell was tested by using an ECM 700 electrochemicl measuring system (Zentrum fuer wissenschaftlichen Geraetebau, Berlin), with Pt electrodes (0.5 mm diameter) at 0.8 V vs. Ag - AgCl and at different effective volume (0.5 to 6.3 µL), with K4Fe(CN)6 as analyte in a flow of 1 M KCl at 0.1 and 0.3 mL min-1. Response times were 0.2 to 6.8 s, with rectilinear calibration up to 50 ng and a detection limit of 25 pg.
Ferricyanide Electrode Flowcell Detector

"Survey Of Electrodes Used For Voltammetric Analysis"
Z. Chem. 1990 Volume 30, Issue 4 Pages 117-129
Alan M. Bond1, Fritz Scholz

Abstract: In this review, the topics discussed are electrode construction (macro-electrodes, micro-electrodes, solid, paste and liquid electrodes), electrode material (noble metals), C, Hg, and surface-modified electrodes) and flow-through electrodes, as used for detection in LC and flow injection analysis. (300 references).
Voltammetry Review

"Electrochemical Detection In Flowing Solutions"
Z. Chem. 1988 Volume 28, Issue 6 Pages 197-204
Hendrik Ernons, Gabriele Jokuszies

Abstract: A review is presented on the principles and applications of conductometric, potentiometric, voltammetric and coulometric detection in flow injection analysis and HPLC, with emphasis on dynamic interfacing techniques. Factors considered in selection of favourable cell designs include sensitivity, linear dynamic range, response time, selectivity and stability. Applications of amperometric detectors are summarized. (114 references).
Amperometry HPLC Conductometry Coulometry Potentiometry Review Linear dynamic range

"Voltammetric Detector For Flowing Systems"
Z. Chem. 1988 Volume 28, Issue 3 Pages 113-114
Gabriele Jokuszies, Hendrik Emons

Abstract: A wall-jet cell comprising a Pt working electrode, a Ag counter electrode and a Ag - AgCl reference electrode (described and illustrated) was incorporated into a detector for HPLC or flow injection analysis. The detector cell was characterized by the amperometric oxidation of K4Fe(CN)6. The most favourable working electrode potential, determined by recording hydrodynamic polarograms of 1 mM K4Fe(CN)6 in 0.1 M KCl at increasing electrode potential from 0 to +1 V, was +0.4 V.
HPLC Electrode Electrode Polarography Voltammetry Apparatus Detector

"Determination Of α-amylase By Flow Injection Analysis"
Z. Chem. 1987 Volume 27, Issue 9 Pages 333-334
Volkmar Müller, Helmut Müller

Abstract: A flow injection system is described for assay of amylase(I) by a reaction involving starch solution as substrate, dinitrosalicylic acid as color reagent and monitoring (at 525 nm) of the formation of aminosalicylic acid. The calibration graph is rectilinear up to 52 iu mL-1 and the limit of detection is 0.3 iu mL-1; 17 to 20 samples can be analyzed in 1 h.
α-Amylase Spectrophotometry

"Spectrophotometric Flow-through Method For The Determination Of Phosphate After Reduction Of Molybdophosphoric Acid At A Bubble Electrode"
Z. Chem. 1986 Volume 26, Issue 8 Pages 298-299
Fritz Scholz, Günter Henrion, Kerstin Weinberg

Abstract: Molybdophosphoric acid is reduced to phosphomolybdenum blue by passage through a cell with mercury and mercury - HgCl2 electrodes, of low dead volume and containing an ion-exchange membrane, which is coupled to a continuous-flow colorimeter. With reduction at -0.3 V vs. silver - AgCl, the calibration graph is rectilinear in the range 10 µM to 0.5 mM PO43-. The coefficient of variation (n = 10) is 1.9% at 0.4 mM.
Phosphate Electrode Ion exchange Spectrophotometry Electrochemical product conversion

"Kinetic Determination Of Traces Of Iron By Means Of Flow Injection Analysis Based On The Catalytic Oxidation Of Leucomalachite Green By Hydrogen Peroxide"
Z. Chem. 1986 Volume 26, Issue 4 Pages 142-143
Helmut Müller, Volkmar Müller

Abstract: Optimum conditions of reagent concentration, activator concentration, pH and reaction time are established for the reaction, in which 30 µL of sample solution is injected into a flow of 1.26 mM leucomalachite green in buffer solution of pH 2.5 mixed wth a solution 0.05 M in H2O2 and 5.5 mM in 1,10-phenanthroline, which is present as activator. Absorbance is measured at 603 nm after a fixed time of >2 min. A detection limit of 30 ng mL-1 in a 30 µL sample is established. Interference by Co(II), Mo(VI), Cu(II), Mn(II), Zn(II), Ni(II) and Cr(III) is evaluated. Between 30 and 60 samples can be analyzed in 1 h.
Iron Spectrophotometry Catalysis Interferences Kinetic Optimization

"Bubbleelectrodes - New Flow-through Electrodes For Analytical, Preparative And Spectroscopical Applications"
Z. Chem. 1985 Volume 25, Issue 4 Pages 121-125
Fritz Scholz, Günter Henrion

Abstract: A review is presented, with 22 references, in which the theory and applications of bubble electrodes are discussed. Such electrodes find applications in electrolysis, e.s.r., and detection in HPLC or flow injection analysis.
Cadmium Electrode Voltammetry Review

"Principles And Applications Of Flow Injection Analysis"
Z. Chem. 1984 Volume 24, Issue 3 Pages 81-93
Helmut Müller, Volkmar Müller

Abstract: Principles of flow injection analysis, including dispersion effects, are described, and the system is discussed in terms of its transport, injection, reaction (e.g., dialysis, dilution, extraction and chemical reaction), detection and data-processing components. An extensive table is presented of applications in clinical, pharmaceutical, water and agricultural chemistry, with details of detection systems and detection limits. Special flow injection methods, e.g., the stopped-flow technique, titration, and closed-system operation, are also discussed. (174 references).
Caffeic acid Ferricyanide Agricultural Pharmaceutical Clinical analysis Sample preparation Closed loop Dialysis Dilution Dispersion Extraction Review Stopped-flow

"Determination Of Water In Organic Solvents By Using The Karl Fischer Method With Flow Injection Analysis"
Z. Chem. 1984 Volume 24, Issue 2 Pages 75-76
Helmut Müller, Günter Wallaschek

Abstract: Liquid paraffin is pumped into the reservoir to force the Karl Fischer reagent in two parallel streams into phase-separation vessels; in this way the reagent does not make contact with the pump tubing. The lower (reagent) phase from the separation vessels flows to the detection system; one stream passes the sample-introduction system and traverses a delay coil. A µflow-through I--selective electrode (Ag2S type) is used for potentiometric measurement, and the differential response is recorded. Calibration standards are included in each series of analyzes to compensate for changes in electrode response as its surface acquires an iodine-containing coating. From 0.01 to 5% (w/w) of water can be determined with a coefficient of variation of 3%, and 50 to 60 samples (e.g., 30 µL) can be analyzed in 1 h; only 0.9 mL of reagent is needed per determination.
Water Organic compound Industrial Electrode Karl Fischer analysis Potentiometry