Record Details
Coulometric determination of dissolved oxygen
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Coulometric determination of dissolved oxygen |
| Names |
Healy, Michael Lyon
(creator) Freund, Harry (advisor) |
| Date Issued | 1965-05-14 (iso8601) |
| Note | Graduation date: 1965 |
| Abstract | Many different aspects of the determination of dissolved oxygen by controlled potential coulometry were investigated to find a means of measuring the oxygen content of natural waters. Rapid sampling techniques, simplicity of operation, and rugged structural features were stressed. Cells were designed to operate by either internal electrolysis or external potential control. A type of steel flow cell of optimum geometry was designed, and measured oxygen in flow streams with 3% accuracy. Periodic sampling was found to be superior to flow analysis, and the flow cell operated by a method of periodic entrapment of sample yielded the most promising results. 0.2% reproducibility was obtained for samples which contained one to five ppm dissolved oxygen, and 1% reproducibility for samples below one ppm. The error in the analysis could not be distinguished from the two percent error in the Winkler titration which was used to determine the standards. Other sample entrapment cells of a different design and with different cathode materials were studied. Two vibrating electrode cells were investigated and found to give no better results than those cells which permit oxygen reduction in quiet solutions. Mercury, gold, platinum, nichrome, stainless steel, and brass were tested as cathode materials. The polarographic and coulometric behavior of dissolved oxygen reduced in cathodes of these materials is described. The investigation of mercury as a cathode material led to the development of an empirical method that relies on the rapid reduction of oxygen on a mercury-electrolyte interface. In one case, 0.5% reproducibility was obtained for individual samples determined at the rate of one every 15 seconds. The utility of these devices, although the current efficiency is low, is pointed out as their potential use as flow stream monitors. The entire work yielded information based on new approaches for the development of ocean-going devices which will measure dissolved oxygen concentrations by controlled potential coulometry to a better degree of accuracy than the existing methods. Design theory and cell construction is presented for devices that operate where rapidity of successive determinations is more important than absolute accuracy. |
| Genre | Thesis/Dissertation |
| Topic | Oxygen |
| Identifier | http://hdl.handle.net/1957/47985 |
