title: Purification and characterizing properties of analytical reagent quinizarin-2-sulphonic acid and its sodium salt.
abstract: Quinizarin-2-sulphonic acid and its sodium salt have been purified for analytical use. The thermal analysis behaviour and the infrared and NMR spectra of the reagent have been recorded. Absorptiometry at 465 nm is recommended for the assay of solutions. Spectrophotometric measurements, corrected for fading, are treated by a PITMAP-type procedure to obtain acid dissociation constants for the reagent. Finally, some reactions with metal ions are surveyed briefly.
authors.affiliation: Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Thomson
authors.forename: G F
authors.initials: GF
authors.lastname: Atkinson