An ultramicro oxygen electrode

1964 ◽  
Vol 19 (2) ◽  
pp. 326-329 ◽  
Author(s):  
Irving Fatt
Keyword(s):  
Platinum Electrode ◽  
Oxygen Electrode ◽  
Electrode Modification ◽  
Mechanical Pressure ◽  
Platinum Cathode ◽  
Oxygen Measurement ◽  
Unstirred Solution

The advantages of a 1-μ-diameter platinum cathode in the Clark-type oxygen electrode are shown to be freedom from effects due to flow, stirring, or mechanical pressure. When used with a 5-mil polyethylene membrane the 1-μ electrode shows only a 2% difference between a vigorously stirred solution and the unstirred solution. A mechanical pressure of 200 psi on the 1-μ covered electrode caused only a 20% reduction in current. The use of a 1-μ covered electrode as an implant is suggested. electrode implant; Clark-type oxygen electrode modification; polarographic electrode; oxygen measurement; platinum electrode Submitted on March 4, 1963

Electrodeposition of Cu2O Particles by Using Electrolyte Solution Containing Glucopone as Surfactant

2009 ◽  
Vol 1 (2) ◽  
pp. 18-20
Author(s):  
Dahyunir Dahlan
Keyword(s):  
Indium Tin Oxide ◽  
Pulse Current ◽  
Platinum Electrode ◽  
Saturated Calomel Electrode ◽  
X Ray Diffraction ◽  
X Ray ◽  
Glass Substrates ◽  
Continuous Current ◽  
Oxide Particles ◽  
Cupric Sulphate

Copper oxide particles were electrodeposited onto indium tin oxide (ITO) coated glass substrates. Electrodeposition was carried out in the electrolyte containing cupric sulphate, boric acid and glucopone. Both continuous and pulse currents methods were used in the process with platinum electrode, saturated calomel electrode (SCE) and ITO electrode as the counter, reference and working electrode respectively. The deposited particles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that, using continuous current deposition, the deposited particles were mixture of Cu2O and CuO particles. By adding glucopone in the electrolyte, particles with spherical shapes were produced. Electrodeposition by using pulse current, uniform cubical shaped Cu2O particles were produced

Comparison of Gold and Platinum Electrode Responses in Activated Sludge

1993 ◽  
Vol 28 (11-12) ◽  
pp. 473-480
Author(s):  
A. Heduit ◽  
B. Martin ◽  
I. Duchamp ◽  
D. R. Thevenot
Keyword(s):  
Electron Transfer ◽  
Activated Sludge ◽  
Gold Electrode ◽  
Platinum Electrode ◽  
Electrochemical Determination ◽  
Exchange Current ◽  
Experimental Conditions ◽  
Equilibrium Exchange ◽  
Prolonged Contact ◽  
Current Densities

Gold and platinum were compared to ascertain how they expressed a stabilized potential in activated sludge. The comparison was based on electrochemical determination of the electron transfer rate (i.e. equilibrium exchange current density) and recording of potentials against time. When both metals are treated in the same way, platinum gives equilibrium exchange current densities approx. 10 times higher than gold, both in aerated activated sludge and in treated water. For platinum, the equilibrium exchange current densities range from 0.1 to 0.25 µA/cm2 immediately after polishing and decrease during prolonged contact with activated sludge subjected to alternating aeration/anoxia sequences. The lower kinetics of electron transfer on gold go together with significant differences in response:- In an aerobic medium a gold electrode potential is lower than that of a platinum electrode. In a strongly anaerobic medium, the reverse is true. Consequently, the amplitude of the potential variation between aerobic and anaerobic media is smaller for gold than for platinum. Under our experimental conditions this amplitude was approx 350 mV for gold and 850 mV for platinum.- The slopes of the linear relationships between potential and pH or potential and the logarithm of the dissolved oxygen concentration are two or three times greater for platinum than for gold. Although the values obtained with platinum electrodes cannot represent a veritable equilibrium state, the platinum electrode zero-current potential would seem to be far more sensitive to variations in the medium than that of the gold electrode; it is, therefore, more suitable for use in activated sludge.

Determination of aeration capacity of bubbled column type fermentors with oxygen electrode

1978 ◽  
Vol 43 (3) ◽  
pp. 713-718 ◽  
Author(s):  
Jaroslav Votruba ◽  
Miroslav Sobotka ◽  
Aleš Prokop
Keyword(s):  
Oxygen Electrode ◽  
Column Type ◽  
Aeration Capacity

Amperometric assay of vitamin C using an ascorbate oxidase enzyme electrode

1979 ◽  
Vol 44 (11) ◽  
pp. 3395-3404 ◽  
Author(s):  
Pavel Posádka ◽  
Lumír Macholán
Keyword(s):  
Ascorbic Acid ◽  
Vitamin C ◽  
Oxygen Electrode ◽  
Ascorbate Oxidase ◽  
Current Response ◽  
Reaction Conditions ◽  
Long Term Storage ◽  
Oxidase Enzyme ◽  
Optimal Reaction

An oxygen electrode of the Clark type, coated by a thin, active layer of chemically insolubilized ascorbate oxidase from squash peelings specifically detects by measuring oxygen uptake 10 to 400 μg of ascorbic acid in 3 ml of phosphate buffer. The record of current response to substrate addition lasts 1-2 min. The ascorbic acid values determined in various samples of fruit juices are in good agreement with the data obtained by titration and polarography. The suitable composition of the membrane and its lifetime and stability during long-term storage are described; optimal reaction conditions of vitamin C determination and the possibilities of interference of other compounds are also examined. Of the 35 phenols, aromatic amines and acids tested chlorogenic acid only can cause a positive error provided that the enzyme membrane has been prepared from ascorbate oxidase of high purity.

The voltammetric determination of 4-nitrobiphenyl

1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima
Keyword(s):  
Differential Pulse Voltammetry ◽  
Differential Pulse ◽  
Voltammetric Determination ◽  
Hanging Mercury Drop Electrode ◽  
Optimum Conditions ◽  
Mercury Drop Electrode ◽  
Working Electrode ◽  
Pulse Voltammetry ◽  
Unstirred Solution

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.

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