title: The protonated 4,4'-diaminotriphenylmethyl cation as a reagent and cyclohexanone as an absorbant for sulphur dioxide determination.
abstract: Protonated 4,4'-diaminotriphenylmethyl cation, DATM, has been investigated as a colorimetric reagent for the determination of sulphur dioxide. The bisulphite addition compound with formaldehyde alkylates a primary arylamine group in the protonated reagent to re-establish resonance, and hence produces a colour that is proportional in intensity to the concentration of either bisulphite or formaldehyde (the other being in excess). The large bathochromic spectral shift results in a negligible blank correction. Cyclohexanone in aqueous solution has been found to stabilize bisulphite solutions for up to 6 hr. The stabilization by cyclohexanone has been compared with stabilization by tetrachloromercurate(II). The Beer-Lambert law is obeyed with good precision for both sulphite and formaldehyde determination.
authors.affiliation: Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Lambert
authors.forename: M J
authors.initials: MJ
authors.lastname: Chejlava
authors.forename: M H
authors.initials: MH
authors.lastname: Beyad
authors.forename: J V
authors.initials: JV
authors.lastname: Paukstelis