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Characteristics of interaction of humic acids in water with ferric ionsтезисы доклада
- Авторы: Gorbunova N.V., Korvatovskiy B.N., Кydralieva К.А., Patsaeva S.V., Paschenko V.Z., Khundzhua D.A., Yuzhakov V.I., Yurischeva А.А.
- Сборник: 11th International Conference “Atomic and Molecular Pulsed Lasers”: Abstracts / Eds. M.Gerasimova, E.Kiselyova and A.Klimkin
- Тезисы
- Год издания: 2013
- Место издания: Publishing House of IAO SB RAS Tomsk
- Первая страница: 90
- Аннотация: Investigation of humic acids (HA) interaction with ferric ions in water is interesting for evaluation of HA adsorptive properties and interpretation of environmental monitoring data. Absorption, fluorescence spectra, fluorescence decay kinetics were studied upon addition of ferric chloride to HA solution and changing its pH. Absorption spectra were recorded using Unico photometer, fluorescence spectra were measured with Solar CM2203. Fluorescence decay kinetics were registered with a fluorometer based streak camera Agat-SF3 with time resolution of 10 ps and YAG-laser with light pulse duration of 20 ps. At low ferric salt concentrations up to 20 fluorescence quantum yield was reduced almost twice, but there were no substantial changes in the HA fluorescence band-shape, and the Stern-Volmer dependences remained linear. For salt concentration above 20 the quenching of HA fluorescence was more effective, the quantum yield reduced by an order or more, and the Stern-Volmer dependences became nonlinear. The measured fluorescence kinetics was fit with two exponents (fast ~ 0.4 ns and slow ~ 2 ns). Ferric chloride had virtually no effect on HA fluorescence kinetics, but significantly reduced its fluorescence quantum yield. We conclude that HA fluorescence quenching by ferric ions occurs through static mechanism, and cooperative effect is seen with increasing ferric ions concentration.
- Добавил в систему: Пацаева Светлана Викторовна