The protonated 4,4'-diaminotriphenylmethyl cation as a reagent and cyclohexanone as an absorbant for sulphur dioxide determination.
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.
Lambert
J L
JL
Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, USA.
Chejlava
M J
MJ
Beyad
M H
MH
Paukstelis
J V
JV