N-substituted phenothiazines as redox indicators in titrations with chloramine-T and chloramine-B.
Profenamine hydrochloride, fluphenazine dihydrochloride, trifluopromazine hydrochloride, cyamepromazine maleate, perphenazine dihydrochloride and mepazine hydrochloride are proposed as redox indicators in the titration of hydroquinone, metol and ascorbic acid with chloramine-T and chloramine-B in sulphuric, hydrochloric and acetic acid media. They give a sharp reversible colour change at the equivalence point. A simple but accurate method for the determination of hydroquinone, metol and ascorbic acid is described. The conditional potentials and molar absorptivities of the indicators and redox potential of chloramine-B are reported.
Gowda
H S
HS
Department of Post-graduate Studies and Research in Chemistry, University of Mysore, Manasa Gangotri, Mysore, India.
Mohan
B M
BM
Ahmed
S A
SA