Polarographic reduction of some triphenylmethane dyes and their potential carcinogenic activity.

Polarographic reduction of some triphenylmethane dyes in strictly anhydrous solutions was studied in the absence and presence of alpha-lipoic acid. The values of the half-wave potentials E1/2 and the parameter of potential carcinogenicity tg alpha were determined for all compounds studied. The current value of the first diffuse polarographic wave was increased in the presence of alpha-lipoic acid for all of the compounds. The increase was linear and depended on the alpha-lipoic acid concentration in anhydrous solutions. The highest determined value of tg alpha belonged to crystal violet (0.420) and to methyl violet 2B (0.440). The values indicate potential carcinogenic activities of the respective triphenylmethane dyes.