Individual and joint kinetic fluorometric determination of imidazole and 4-methylimidazole

The oxidation of 1,1,3-tricyano-2-amino-1-propene in the presence of hydrogen peroxide and copper is favored by imidazole, 4-methylimidazole, or any other compound possessing the imidazole ring. This fluorescent reaction has been used for the individual determination of imidazole and 4-methylimidazole at 10⁻⁵M level by application of several kinetic methods (tangent, fixed-time, and maximum fluorescence intensity) with a precision (%RSD) of about ±1%. A differential-rate principle allows the determination of binary mixtures of both compounds, which is subject to synergistic effects. Mixtures of imidazole and 4-methylimidazole in ratios between 1:1 and 1:9 have been resolved with a %RSD of ±7.1% for imidazole and ±3.1% for 4-methylimidazole.