Potentiometric Determination of Acidity in Insulating Oils

Potentiometric Electrode Systems In Nonaqueous Titrimetry

“…The ratios of the dissociation constants of mono-, di-, and triphenylacetic acids in methanol, ethanol, and water have been measured using a concentration cell with quinhydrone--gold electrodes (114). The determination of the acidity of oils has been studied by titration in butanol (29,50,177) and in isoamyl alcohol (176). Ruehle (169) has shown that acetone, anisóle, and dioxane can be used to enhance the solvent powers of butanol without interfering with the functioning of the quinhydrone electrode in this solvent.…”

“…This modification was also reported by Ohlweiler and Meditsch (143). A much earlier use of this reference electrode was for the determination of acidity of oils by titration in 1-butanol saturated with lithium chloride (50,177). Erratic readings have been reported in the region of the end point in acetic acid.…”

Determination of Acidity in Insulating Oil

“…The use of quinhydrone with oils that contain peroxides should be questioned. When using the glass electrode no quinhydrone and conducting salt are necessary in the titration medium (2,4,10,11,12). However, peroxides present an unavoidable difficulty, in that they are attacked A. Titration of 0.9 cc.…”

Potentiometric titration of acidity in oils

“…Inasmuch as carbon and natural graphite gave equally good results, small arc-light carbons were used. The advantages of this electrode pair are (1) simplicity, (2) compactness, (3) high electrical conductivity, (4) low resistance contact with the solution, and (5) large potential change at the end point (100 to 250 millivolts).…”