The Composition and, in Particular, the Disinfectant Value of the Phenols in Coal Tars from Various Sources

Moore, Quinti (1933) The Composition and, in Particular, the Disinfectant Value of the Phenols in Coal Tars from Various Sources. PhD thesis, University of Glasgow.

Abstract

The literature on the subject of disinfection with phenolic bodies is very extensive but much the greater part of it is concerned only with the lower boiling fractions of the phenols from which phenol and the cresols, in a pure state, may be isolated with comparative ease. The object of the present research is to examine the phenols of higher boiling points, from which few pure products have so far been isolated, in order to determine whether knowledge of their disinfectant value in addition to known physical constants will assist in distinguishing, or proving relationship, between phenols from different sources such as from low temperature or high temperature coal-tars. Owing to the low solubility of the high boiling phenols in water it was necessary to employ them in an emulsified form. Methods of emulsifying the phenols were studied and comparisons were made between the disinfectant value and the average size of the emulsion particles, in order to obtain the most efficient type of preparation and to determine the extent of variation of the disinfectant value with alteration in the emulsion particle size. The disinfectant values were determined by the Rideal-Walker method and, during the progress of the work, one cause for inconsistent results was traced to the relatively inaccurate method of standardising the broth culture medium. Slight variations in the acidity of the broth were found to change the phenol coefficient value of the same disinfectant preparation and, after publication of the results, the official method of standardising the broth was revised. The comparison of the phenols from different sources of tar was commenced after ascertaining the best methods to obtain consistent results for the disinfectant values of the phenols. In the comparison, identical fractions of the phenols from four tars were prepared and the disinfectant values of the fractions were compared with those of pure phenols. The results of the research work are presented under the following four headings: (1) Introductory review of literature. (2) Preparation of disinfectant emulsions and compar- ison of their germicidal power with emulsion particle size determinations. (3) Effect of slight variation in the adjustment of the acidity of Rideal-Walker broth upon the phenol coefficient value of coal-tar disinfectants. (4) Comparison of the disinfectant value of the phenols from different sources of tar.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1933
• Depositing User: Enlighten Team
• Unique ID: glathesis:1933-79985
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 03 Mar 2020 10:14
• Last Modified: 03 Mar 2020 10:14
• URI: https://theses.gla.ac.uk/id/eprint/79985