Method for detecting hydrogen peroxide employing triaryl- and trihetarylmethane derivatives as redox indicators

A method for detecting hydrogen peroxide comprising contacting a sample with a peroxidase or a peroxidatively-active substance and a reflux indicator of the formula ##STR54## in which A and D, independently of one another represent unsubstituted phenyl, pyridyl or imidazolyl or phenyl, pyridyl, or imidazolyl substituted by halogen, hydroxyl, alkoxy, aryloxy, aralkoxy, aryl, cycloalkyl, hetaryl, alkylmercapto, arylmercapto, alkylsulphonyl, cyano, alkylcarbonyl, alkylcarbonyloxy, nitro, acylamino, alkylsulphonic acid, arylsulphonic acid, alkylcarboxylic acid, aralkylcarboxylic acid, amino which is unsubstituted or substituted by 1 or 2 alkyl, aryl or aralkyl groups, which themselves are unsubstituted or substituted by halogen, cyano, hydroxyl, sulphonic acid, carboxylic acid or substituted amino, or amino groups, the substituents of which are cyclized,

• G represents O, CH.sub.2 or S,
• m represents the number zero or one,
• X represents ##STR55## --NR.sup.1 --NR.sup.2 --, R.sup.1 and R.sup.2 denote hydrogen and
• T denotes hydrogen, hydroxyl, alkyl, aryl, alkoxy, phenoxy, SO.sub.3 H, --COOH or ##STR56## whereby a color change is brought about if hydrogen peroxide is present and detecting any color change in the sample.