SEDL / STP / STP1096-EB / STP20109S

Reducible Dye 2-(p-lodophenyl)-3-(p-Nitrophenyl)-5-(Phenyl)-2H-Tetrazolium Chloride (INT) for Use in Aquatic Toxicology: Notes on Chemical Structure, Electrochemistry, and Toxicity

Catallo, WJ
Virginia Institute of Marine Science, College of William and MaryInstitute for Environmental Studies, Louisiana State University, Gloucester PointBaton Rouge, VALA

Gale, RJ
Louisiana State University, Baton Rouge, LA

Wong, RL
Louisiana State University, Baton Rouge, LA

Bender, ME
Virginia Institute of Marine Science, College of William and MaryInstitute for Environmental Studies, Louisiana State University, Gloucester PointBaton Rouge, VALA

Pages: 15    Published: Jan 1990

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Abstract

Studies of 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-(phenyl)-2H-tetrazolium chloride (INT) chemical structure and aqueous electrochemistry at Hg, C, and Pt electrodes were conducted to address conceptual difficulties in published literature and questions arising from INT behavior in our bioassay systems. Data presented include nuclear magnetic resonance spectra and consistent chemical structures for INT, INT formazan, and an extract from INT-treated Escherichia coli cells. Results from normal and differential pulse polarography, cyclic voltammetry, and spectrochemical determination of minimum potentials for INT reduction on Pt are reported and given mechanistic interpretations. The results of experiments with INT on C and Pt electrodes suggested interfering electrode reactions involving hydrogen. An expanded reaction scheme is proposed based on these observations. Preliminary mutagenicity testing on INT and its reduction products was conducted using the Ames/Salmonella assay. The results of these assays are presented.