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Title: Applications of polarography and related techniques in organic analysis
Author: Brand, Michael John Dinnis
Awarding Body: University of London
Current Institution: Imperial College London
Date of Award: 1968
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The polarographic behaviour of cinnamic acid and a series of substituted cinnamic acids (4-cyano, 3- and 4- chloro, 4-bromo, 3-and 4- methoxy, 4-methyl) has been investigated. With the exception of 4-cyano cinnamic acid, each acid was reduced via a protonated complex of the anion to the saturated acid. The course of reduction of 4-cyano cinnamic acid was pH dependent. In acid solution the nitrilo group was reduced to a primary amine while in neutral and alkaline solutions the olefinic group was reduced both in a protonated complex of the anion and in the unprotonated anion, A comparison has been made of the polarographic behaviour of some derivatives of dithiocarbamic acid which are used as fungicides, i.e. alkyl dithiocarbamates, ethylene bis dithiocarbamates and thiuram disulphides. The application of a.c. polarography to the determination of these compounds was considered. Linear potential sweep chronoamperometry was applied to the determination of alkyl dithiocarbamates at a dropping mercury electrode. The use of cathodic potential sweeps gave a greater sensitivity than did anodic sweeps; this effect was due to formation of an insoluble salt at the electrode surface during the delay period before the potential sweep was applied. The pre-concentration of dithiocarbamates at a mercury electrode was used as a basis of a method for their determination by cathodic stripping voltammetry. The method was applied to all three types of dithiocarbamate with a lower sensitivity limit of 10-8 M. Finally, an operational amplifier instrument for controlled alternating current oscilloscopic polarography was designed and constructed, The instrument was evaluated for the application of sine, triangular and square wave currents at variable frequencies.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available