Перегляд за Автор "Nevmerjitcaia, K. S."

Зараз показуємо 1 - 1 з 1
  • Ескіз
    Документ
    The Features of Pyrocatechol Violet Complexation with Mo(VI) and W(VI) in solutions. The Spectrophotometric Determination of Mo(VI) in Multivitamins
    (2017) Chebotaryov, Oleksandr M.; Snigur, Denys V.; Dubovyi, V. P.; Shcherbakova, Tetiana M.; Bevziuk, Kateryna V.; Nevmerjitcaia, K. S.; Чеботарёв, Александр Николаевич; Снигур, Денис Васильевич; Дубовый, Виталий Петрович; Щербакова, Татьяна Михайловна; Бевзюк, Екатерина Викторовна; Невмержицкая, Е. С.; Чеботарьов, Олександр Миколайович; Снігур, Денис Васильович; Щербакова, Тетяна Михайлівна
    The conditions of an interaction of molybdenum(VI) and tungsten(VI) with pyrocatechol violet (PCV) have been studied and optimized. The PCV complexation with Mo(VI) and W(VI) takes place in the pH range of pH 1÷4 (pH opt 1.5 and 1.1 respectively). The composition of the complexes of Mo(VI) and W(VI) with PCV in binary systems is 1:1 and the molar ratios of light absorption have been calculated (ε550=14000 and ε555=15000, respectively). In the presence of cetylpyridinium bromide (CPBr) it was observed bathochromic shift of the absorption bands of complexes, which is associated with the formation of ion associates. In the ternary systems maximum yield of colored products is observed at pH 4.3, Mo(VI) and pH 4.0 for W(VI). The ratio of components in ternary systems «Mo(VI)/W(VI)-PCV-CPBr» is 1:1:2. The mechanism of Mo(VI) and W(VI) complexation with the PCV has been suggested based on the spectrophotometric data aggregate. The binary and ternary systems the coordinating particles are cations MoO2(OH)+ and WO2(OH)+, and the PCV reacts by dissociating of sulfogroup form. In ternary systems cetylpyridinium cation involved in the formation of ion associates due to their electrostatic interaction of with sulfo and hydroxy groups of PCV. The molar absorbance coefficients of ionic associates «Mo(VI)-PCV-CPBr» and «W(VI)-PCV-CPBr» are equal ε670=57000 and ε670=61000, and Beer’s law is observed in the concentration range of 0.3-25 μg/mL and 0.2-23 μg/ml, respectively.