Glass Electrode as Reference Electrode in Electrometric Titrations

1942 ◽  
Vol 14 (1) ◽  
pp. 67-69 ◽  
Author(s):  
Louis Lykken ◽  
F Tuemmler
Keyword(s):  
Reference Electrode ◽  
Glass Electrode

Determination of Sodium in Urine by Specific Ion Electrode

1967 ◽  
Vol 13 (3) ◽  
pp. 227-232 ◽  
Author(s):  
Joseph S Annino
Keyword(s):  
Excellent Agreement ◽  
Reference Electrode ◽  
Sodium Concentration ◽  
Glass Electrode ◽  
Sodium Ion ◽  
Flame Photometry ◽  
Standard Curve ◽  
Sodium Activity ◽  
Ion Activity

Abstract A method has been developed for determination of sodium concentration (activity) in urine using a glass electrode designed to be especially sensitive to sodium ion activity. The urine is diluted 2:20 with Tris buffer (pH 8.0) and sodium activity measured by dipping a sodium electrode and calomel reference electrode in the diluted specimen and obtaining a millivolt reading with a sensitive pH meter. The sodium concentration is then calculated from a predetermined standard curve. Concentrations of 0-200 mEq./L. may be read using the same dilution. Blind comparisons of sodium concentrations obtained by flame photometry and by sodium ion electrode showed excellent agreement.

Guidelines for potentiometric measurements in suspensions Part A. The suspension effect (IUPAC Technical Report)

2007 ◽  
Vol 79 (1) ◽  
pp. 67-79 ◽  
Author(s):  
Srecko F. Oman ◽  
M. Filomena Camões ◽  
Kipton J. Powell ◽  
Raj Rajagopalan ◽  
Petra Spitzer
Keyword(s):  
Reference Electrode ◽  
Cell Voltage ◽  
Glass Electrode ◽  
Indicator Electrode ◽  
Liquid Junction ◽  
Technical Report ◽  
Suspension Effect ◽  
The Difference ◽  
Definition Of ◽  
Junction Potential

An explanation of the origin and interpretation of the suspension effect (SE) is presented in accordance with "pH Measurement: IUPAC Recommendations 2002" [Pure Appl. Chem.74, 2169 (2002)]. It is based on an analysis of detailed schemes of suspension potentiometric cells and confirmed with experimental results. Historically, the term "suspension effect" evolved during attempts to determine electrochemically the thermodynamically defined activity of H+ (aq) in suspensions. The experimental SE arises also in determining other pIon values, analogous to pH values.The SE relates to the observation that for the potential generated when a pair of electrodes (e.g., reference electrode, RE, and glass electrode) is placed in a suspension, the measured cell voltage is different from that measured when they are both placed in the separate equilibrium solution (eqs). The SE is defined here as the sum of: (1) the difference between the mixed potential of the indicator electrode (IE) in a suspension and the IE potential placed in the separated eqs; and (2) the anomalous liquid junction potential of the RE placed in the suspension. It is not the consequence of a boundary potential between the sediment and its eqs in the suspension potentiometric cells as is stated in the current definition of the SE.

The errors involved in pH determination in soils.

1954 ◽  
Vol 5 (4) ◽  
pp. 716 ◽  
Author(s):  
M Raupach
Keyword(s):  
Reference Electrode ◽  
Glass Electrode ◽  
Measuring System ◽  
Ph Measurements ◽  
Soil Systems ◽  
Water Suspensions ◽  
Supernatant Liquid ◽  
Soil Variation ◽  
Single Determination ◽  
Suspension Effect

Errors of replication of pH values of 1: 5 soil-water suspensions are shown to differ significantly between routine observers and to be larger when duplicate determinations are made upon different days rather than on the same day. For the routine technique employed in these laboratories the 5 per cent. fiducial limits of a single determination do not rise above ±0.09 pH units due to the above causes. Errors due to soil variation over small distances in the field may show 5 per cent. limits as high as ±1.3 pH units. The causes of the errors which may arise within the measuring system are considered and details are given of errors in soil systems due to the suspension effect and to lack of equilibrium between the soil and aqueous phases. Absence of equilibrium may give differences as high as 1.0 unit when measurements are made upon sedimenting alkaline suspensions; no errors occur due to this cause below pH 5. The presence of salts does not modify the differences observed. The suspension effect is relatively small. It is recommended that where possible, pH measurements be made upon soil systems with the glass electrode in the suspension and the reference electrode in the dialysate or supernatant liquid. The description and use of a suitable electrode arrangement is given in an appendix. Generally pH measurements can be considered to no greater accuracy than ±0.1 unit and quite often circumstances do not justify this precision.

Formation constants for selected organo—metal (Al3+, Fe3+)—phosphate complexes

1985 ◽  
Vol 63 (12) ◽  
pp. 3357-3366 ◽  
Author(s):  
Paul A. Arp ◽  
W. Lense Meyer
Keyword(s):  
Organic Acids ◽  
Aqueous Solutions ◽  
Reference Electrode ◽  
Formation Constants ◽  
Glass Electrode ◽  
Metal Phosphate ◽  
Electrode Pair ◽  
Phosphate Ions

The possible formation of organo–metal–phosphate complexes (O–M–P) in aqueous solutions is examined by potentiometric titration analysis. The complex-forming solutions contain Al3+-ions or Fe3+-ions, organic acids (salicylic, phthalic, oxalic, and citric acids) and phosphate ions. The titrations are done within the precipitation-free pH-region from 2 to 4.5 (approximately) at 25 °C under nitrogen at an ionic strength of 0.2 M KCl. The calibration of the electrode pair (glass-electrode, calomel-reference electrode) and the determination of the formation constants are facilitated by analyzing the pertinent curves with the ACBA-(Arena etal.) and MINIQUAD-(Gans etal.) computer programs. The results suggest (i) that O–M–P complexes are readily formed, and that the power of selected organic acids to form ternary mixed-ligand complexes with Al3+-ions and phosphate ions decreases in the order salycilate > citrate > oxalate > phthalate. Also, Fe3+-ions are found to be more strongly bound by salicylate and phosphate ions than Al3+-ions. The effect of O–M–P formation on the chemical speciation of Al in buffered aqueous solutions containing mineral nutrients for the growth of biological organisms is demonstrated for a special case study.

Electrochemical Measurements during the Anaerobic Corrosion of Steel

2000 ◽  
Vol 663 ◽  
Author(s):  
N.R. Smart ◽  
P.A.H. Fennell ◽  
R. Peat ◽  
K. Spahiu ◽  
L. Werme
Keyword(s):  
Redox Potential ◽  
Silver Chloride ◽  
Steel Wire ◽  
Reference Electrode ◽  
Glass Electrode ◽  
Spent Fuel ◽  
Geologic Repository ◽  
Steel Electrode ◽  
Anaerobic Corrosion ◽  
Corrosion Of Steel

ABSTRACTIn Sweden, it is proposed that spent fuel should be encapsulated in sealed cylindrical canisters for disposal in a geologic repository. The canisters would consist of a thick ferrous inner container and a copper overpack. If mechanical failure of the copper overpack occurred, allowing water to enter, the ferrous inner container would corrode anaerobically and liberate hydrogen. The rate of hydrogen generation due to the anaerobic corrosion of steel in anoxic groundwater has been measured using barometric cells. The aim of the work presented in this paper was to measure the redox potential, Eh and pH in the presence of anaerobically corroding steel, in a barometric cell. Two specially designed barometric cells were constructed. They were equipped with a silver chloride or calomel reference electrode, a gold Eh electrode, a glass electrode, and a steel electrode. The electrodes were allowed to stabilize in anoxic artificial groundwater and then a mass of pickled steel wire was introduced into the test cell. As the wires were added, the redox potential rapidly became more negative due to the rapid consumption of the residual oxygen. The corrosion potential of the steel was stable and a slow drift in pH was observed. The results are compared with the results of geochemical modelling. Extension of the work to investigate the electrochemical parameters in the presence of dissolved uranium species is discussed.

Recent advances in analytical potentiometry with ion-selective electrodes

1982 ◽  
Vol 305 (1491) ◽  
pp. 631-644 ◽  
Keyword(s):  
Field Effect Transistor ◽  
Liquid Membrane ◽  
Reference Electrode ◽  
Glass Electrode ◽  
Ion Selective Electrodes ◽  
Selective Electrode ◽  
Solution Interface ◽  
Recent Advances ◽  
Effect Transistor ◽  
Historical Developments

Historical developments in analytical potentiometry are briefly introduced and compared with those in polarography and coulometry: in the discussion special emphasis is given to the selectivities of these methods. Next, recent advances are described in ion-selective electrodes of both the solid membrane and the liquid membrane types; an extremely small ion-selective reference electrode assembly made with a field effect transistor is described and the use of solid solvent as membrane material is discussed. The enhancement of the selectivity of anion electrodes by p-tert -octylphenol is introduced and the effect of the enhancement is explained after a discussion from a voltammetric standpoint of the mechanisms of potential generation at the electrode-solution interface. As an example of the applications of the ion-selective electrode, the use of the cationsensitive glass electrode for the measurement of the activities of metal ions in nonaqueous solvents is introduced.

Evaluation of a molybdenum sulfide reference electrode in hot alkaline solutions

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 35-41
Author(s):  
OUTI A. HYÖKYVIRTA ◽  
TOM E. GUSTAFSSON
Keyword(s):  
Molybdenum Disulfide ◽  
Surface Film ◽  
Reference Electrode ◽  
Exposure Period ◽  
Molybdenum Sulfide ◽  
Alkaline Solutions ◽  
Internal Reference ◽  
Cell Potential ◽  
Pulp Digester ◽  
Alkaline Sulfide

This investigation evaluated the applicability of a molybdenum sulfide reference electrode (MSRE) as an internal reference electrode for use in alkaline sulfide solutions over a range of pulp digester liquors at 170°C. The electrode remained stable during the exposure period of two weeks. The experimentally determined half cell potential of the MSRE is E = -0.91 VSHE. The surface of the MSRE was examined by scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA) to verify the chemical composition of the thin surface film. Based on ESCA studies, the surface film contained molybdenum disulfide and sodium disulfide. During storage of the specimens, sulfide was partly oxidized to sodium sulfite in air. Next to the metallic molybdenum, a mixed molybdenum disulfide and molybdenum hydroxide layer was detected.

Facile and Fast Detection of Genistein in Derris scandens by Square Wave Voltammetry using a Cobalt(II) Phthalocyanine-Modified Screen-Printed Electrochemical Sensor

2020 ◽  
Vol 16 (3) ◽  
pp. 341-348
Author(s):  
Surinya Traipop ◽  
Suchada Chuanuwatanakul ◽  
Orawon Chailapakul ◽  
Eakkasit Punrat
Keyword(s):  
Electrochemical Sensor ◽  
Square Wave Voltammetry ◽  
Silver Chloride ◽  
Reference Electrode ◽  
High Sensitivity ◽  
Plastic Substrate ◽  
Fast Analysis ◽  
Square Wave ◽  
Wave Voltammetry ◽  
Screen Printed

Background: Recently, Derris scandens, a Thai herbal medicine with anti-inflammatory activity, is widely used as beverage and supplementary food. When the traditional medicine is a choice for health therapy, the simple and reliable equipment is required to control the suitable consuming amount of the active component. Objective: To develop the electrochemical sensor for genistein determination in Derris scandens with high sensitivity and rapid operation. Methods: An in-house screen-printed electrochemical sensor consisting of a three-electrode system was developed for genistein determination. A silver/silver chloride (Ag/AgCl) reference electrode, a carbon counter electrode and a carbon working electrode were prepared on a 0.3-mm-thick plastic substrate by the screen-printing technique using conductive ink. The dimensions of each sensor were 2.5×1.0 cm. Only 50 µL of sample solution was required on this device for the determination of genistein concentration by rapid response square wave voltammetry. Results: The oxidation peak of genistein appeared with good response in acidic media at a peak potential of 0.6 V. Moreover, the signal was enhanced by modifying the conductive carbon ink with cobalt( II) phthalocyanine. Under the optimized conditions, the linear range was found to be 2.5-150 µM and the detection limit was 1.5 µM. Moreover, the small volume extraction was successfully developed without any further pre-concentration. This proposed method was applied to determine genistein in Derris scandens with satisfying results. Conclusion: The proposed method is promising as an alternative method for genistein determination with facile and fast analysis.

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