The dye phenol red (phenolsulphonphthalein) was chemically brominated to bromophenol blue (3',3',5',5'-tetrabromophenolsulphonphthalein) directly by hydrogen peroxide (20 mM or higher) under acidic pH (0.5-4.5) and moderate temperature (30°C). Since this bromination reaction takes place in the absence of any chemical or biological catalyst, the results represent an important warning concerning a commonly used assay for detecting or screening haloperoxidases. Bromophenol red (5',5'-dibromophenolsulphonphthalein) and another unidentified compound were observed as temporary intermediates. Incubation of the reaction mixture with KCl instead of NaBr did not yield any chlorinated products under the same conditions.
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Health, Toxicology and Mutagenesis