Protometric thermometric titrations of sparingly soluble compounds in water in the presence of n-octanol

Abstract Thermometric titrimetry permits titration of acido–basic compounds in water in the presence of n -octanol. n -Octanol permits the solubilization of protolytes and moreover may also displace the equilibria of the titration reactions. Hydrochlorides of highly insoluble derivatives such as phenothiazine derivatives can be titrated with satisfactory accuracy and precision by sodium hydroxide despite their high p K a values. Likewise barbiturate salts can be titrated by hydrochloric acid. In the case of some salts, the methodology may permit the sequential titration of the ion and counter ion.