Spectrophotometric and Fluorescent Determination of Hydrophobic Organic Cations in the Surfactant-modified System Mo(VI)– Bromopyrogallol Red

The spectrophotometric and fluorescent characteristics of the surfactant-modified molybdenum (VI) – bromopyrogallol red reagent system were studied. The hydrophobic modification was achieved by adding cationic, nonionic surfactants, or, accordingly, mixtures of surfactant modifiers into the metal reagent system. Modification of the metal reagent system with a nonionic surfactant leads to a decrease in the limit of detection of the hydrophobic organic cation in the molybdenum (VI) – bromopyrogallol red system by the fluorescence method and an increase in the contrast of the spectrophotometric reaction. The colloid-chemical state of molybdenum (VI) – bromopyrogallol red solutions in the presence of cationic surfactant, nonionic surfactant, and their mixture was also investigated. An increase in the turbidity of the investigated solutions is registered under the conditions of a decrease in the scattering factor, which, in turn, increases the limit of detection of the spectrophotometric determination of decamethoxine in the surfactant-modified molybdenum (VI) – bromopyrogallol red system. Based on the obtained results, the conditions for controlled modification of the metal reagent system with surfactants for the determination of hydrophobic organic cations by molecular spectroscopy methods were proposed. Fluorescence and spectrophotometric detection of decamethoxine content in medicines was carried out in optimized surfactant-modified molybdenum (VI) – bromopyrogallol red systems.