Design and application of electrodes for the determination of dissolved oxygen

Hospodka, J.; Čáslavský, Z.

doi:10.1007/bf02881012

Cited by 10 publications

(6 citation statements)

References 27 publications

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“…These electrodes have been used mainly in the fields of food analysis, biology, medicine, and biochemical engineering (Borkowski and Johnson, 1967;Flynn et al, 1967;Halback, 1977;Hospodka and Caslavsky, 1964;Johnson et al, 1964;Krebs and Haddad, 1972;Koch and Kruuv, 1972;Kok and Zajic, 1973;Kok and Zajic, 1975). Oxygen probes have also been used in the measurement of oxygen in silage (Rees, 1981), natural and wastewaters (Gilbert et al, 1982), for theoretical studies (Rutchi et al, 1981) and in food oxidation (Fioriti, 1977;Fischer and Deng, 1977;Mack et al, 1976;Pominski et al, 1975;Quast and Karel, 1971;Quast and Karel, 1972a;Riemer, 1977;Saguy et al, 1983;Spiehler, 1971;…”

Section: Oxygen Uptake Measurementmentioning

confidence: 99%

Kinetics of Oxidation of Dehydrated Food at Low Oxygen Pressures

Kacyn

Saguy

Karel

1983

J Food Processing Preservation

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An apparatus for the measurement of adsorbed/entrapped oxygen held by dehydrated powdered products was developed and is described in detail.The method works on the principle of sample solubilization in deaerated water with compression of the liberated gases into a calibrated chamber containing an oxygen probe.When tested on nonfat dry milk, the coefficient of variation for the method is 20%.Kinetic studies using this apparatus were performed on a model system consisting of methyl linoleate dispersed on Avicel microcrystalline cellulose and nonfat dry milk at headspace oxygen concentrations of 0.52% -10.69%.Excellent correlation was found in the model system between diene conjugation values and oxygen uptake as measured by the apparatus.Correlation coefficients between the two methods were in the range .987 -. 997.Bimolecular kinetics were found to apply to both the model system and the milk-lipid system with KB's within the range expected from studies done by previous workers at higher 02 pressures.The KB's for the cellulose model system were found to be 5 to 6 times greater than those in the milk based system. This was due partly to encapsulation of lipids in the milk during preparation and partly due to smaller surface area in the milk-based system. Mathematical models for the oxidation rate constants as a function of headspace 02 concentrations were derived for the two systems.

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Section: Oxygen Uptake Measurementmentioning

confidence: 99%

Kinetics of Oxidation of Dehydrated Food at Low Oxygen Pressures

Kacyn

Saguy

Karel

1983

J Food Processing Preservation

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“…Under segregated conditions, a much longer BIOTECHNOLOGY AND BIOENGINEERING, VOL. XIV, ISSUE 4 time is needed for complete utilization of the substrate in the larger drops as has been shown elsewhere.22 The quality of the dispersion may be best at the optimal 4; however, this may be a reflection of a given power input. An optimum in 4 should be understood as the optimum of a given fermentor design and that it is dependent on mixing conditions, e.g., circulation pattern and local turbulence field.…”

Section: Other Observationsmentioning

confidence: 90%

Growth models of cultures with two liquid phases. VII. Substrate dissolved in dispersed phase; effect of dispersed phase volume and temperature

Prokop

Erickson²

1972

Biotech & Bioengineering

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SummaryThe effects of dispersed phase volume and temperature on the batch growth of Cundida Zipolytica on gas oil are investigated. Growth parameters are presented for two sets of experiments. The shape of growth curves was basically similar to the system composed of n-hexadecane dissolved in dewaxed gas oil, in spite of the complex nature of the substance. All of the batch growth curves exhibited a linear growth region. The rate of linear growth and its length varied with change in dispersed phase volume. The effect of temperature on growth rate was investigated for temperatures ranging from 23°C to 34°C. The results show a smaller activation energy during linear growth than during the early stages of batch growth. These results are analyzed from the viewpoint of growth models presented previously. The results indicate that growth at drop surfaces is important and that segregation effects may be important.

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“…(8) for various values of z and Al is given in Figure 2. The "S-shaped" character of the curves is simply related to the physical background of the probe response phenomenon: the first part of the curves (the part with greater negative slope) is determined by the more quickly responding region of the probe; the second part of the curves-i.e., the more slowly decreasing part of the curves-corresponds to the more slowly responding region of the probe.…”

Section: Response To Step Changementioning

confidence: 99%

Multiregion, multilayer, nonuniform diffusion model of an oxygen electrode

Linek

Beneš

1977

Biotech & Bioengineering

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The dynamic characteristic of membrane covered dissolved oxygen probes is usually modeled as being equivalent to a single diffusion layer.'-' But this model fails to describe the slowdown in the last 20% of the response to a step change in oxygen tension. Benedek and Heideger4 suggested that the behavior might be due to sideways diffusion and membrane tautness. Kok and Zajic6 proposed ''a central well model" to explain the slowdown, incorporating a lateral diffusion of oxygen from the anodic compartment to the cathode. The aim of this communication is to show an alternative method of solution where the case under study is reduced to simple cases already described.When the electrode is covered with a nonuniformly stretched membrane, the membrane thickness and the thickness of the electrolyte layer need not be constant over all the cathode area (see Fig. 1). The cathode surface area can be then divided into several regions in which the thicknesses of both the layers (membrane and electrolyte) are uniform. Assuming that there is no sideways diffusion between the regions, the diffusion of oxygen in the membrane and the electrolyte layer can be described by the already known models. The response of such a probe can be obtained as a linear combination of the responses of the regions. Explicit expressions describing the probe responses both to a step change in oxygen concentration and to an exponential one are derived for a more general case: the multiregion, multilayer, nonuniform oxygen diffusion model.The slowdown was observed by many

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Design and application of electrodes for the determination of dissolved oxygen

Cited by 10 publications

References 27 publications

Kinetics of Oxidation of Dehydrated Food at Low Oxygen Pressures

Kinetics of Oxidation of Dehydrated Food at Low Oxygen Pressures

Growth models of cultures with two liquid phases. VII. Substrate dissolved in dispersed phase; effect of dispersed phase volume and temperature

Multiregion, multilayer, nonuniform diffusion model of an oxygen electrode

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