Abstract: Diarylimidazoles of the general formula: ##STR1## wherein R.sup.1 is a radical of the general formula: ##STR2## in which R.sup.3 and R.sup.6 are hydrogen atoms, R.sup.4 and R.sup.5, which can be the same or different, are lower alkyl radicals or R.sup.3 /R.sup.4 and /or R.sup.5 /R.sup.6 in each case together represent a lower alkylene radical and R.sup.2 is a lower alkyl radical, and/or of a salt thereof, are useful as redox indicators, particularly in the presence of a SH group-containing substance.

Abstract: The invention relates to a method for determining an ion in an aqueous sample. The method involves contacting the sample with a water immiscible material including an ionophore, a pH indicator and a compound which stabilizes sensitivity of the assay. The ion reacts with the ionophore in the water immiscible material, releasing a proton which reacts with the pH indicator generating a color change which is representative of the ion to be measured. The stabilizing compound stabilizes this change. Also described are compositions including the three recited elements, and various new compounds useful as the stabilizer.

Abstract: The subject matter of the present invention are naphthol derivatives having the general formula I ##STR1## in which R.sup.1, R.sup.2, R.sup.3 are the same or different and each represents hydrogen, an alkyl or alkoxy group, in which at least one of the residues is a (C.sub.8 -C.sub.30)-alkyl or alkoxy residueR.sup.4 is hydrogen or an alkyl groupR.sup.5 is a nitro group, an alkyl group substituted by halogen, a cyano group, a sulfonamide group or an alkylsulfonyl groupX is nitrogen or the residue CR.sup.6 andY is sulphur or the residue CR.sup.7 =CR.sup.8in which R.sup.6, R.sup.7, R.sup.8 are the same or different and each denotes hydrogen, halogen, a nitro group, a cyano group, an alkyl or an alkyl group substituted by halogen or an alkylsulfonyl group, a process for their production and their use as a pH indicator or in methods and agents for the determination of an ion in an aqueous liquid.

Abstract: Diarylimidazoles of the general formula: ##STR1## wherein R.sup.1 is a radical of the general formula: ##STR2## in which R.sup.3 and R.sup.6 are hydrogen atoms, R.sup.4 and R.sup.5, which can be the same or different, are lower alkyl radicals or R.sup.3 /R.sup.4 and/or R.sup.5 /R.sup.6 in each case together represent a lower alkylene radical and R.sup.2 is a lower alkyl radical, and/or of a salt thereof, are used as redox indicators in the colorimetric diarylimidazoles are not influenced by the presence of a SH group-containing substance. The peroxidate-acting substance can be used to determine the presence of creatine kinase.

Abstract: New 1-naphtholphthalein monophosphates of the formula ##STR1## wherein each of R.sup.1 and R.sup.2 is hydrogen or halogen, and each of M.sup.1 and M.sup.2 is a proton or an alkali metal, alkaline earth metal, ammonium, dicyclohexylammonium, tetraalkylammonium or alkanolammonium cation, and the tautomeric transformation products thereof, are useful as substrates for detection and photometric determination of alkaline phosphotase.