Фракционный И Элементный Состав Гуминовых Веществ Донных Отложений Озер Лесостепной Зоны Тюменской Области

The aim of this work is to determine the elemental composition and types of humic substances extracted from the sediment samples from 6 lakes of the foreststeppe zone of the Tyumen region. The fractionation of humic substances is carried out by the pyrophosphate. To determine carbon, hydrogen, nitrogen and oxygen, the method of elemental analysis is used. The average values of the mass fraction of C, H, O, N for humic acids are 52.9, 4.31, 36.9, 5.88 wt. %; for fulvic acids they are 43.4, 4.96, 46.0, 5.61 wt. % respectively. The atomic ratio of H:C, 0:C and C:N are calculated. The average value (H:C)CORR of humic acids is equal to 1.68 (varying from 1.61 to 1.75), which can be interpreted as a combination of aromatic and aliphatic structures with a predominance of aliphatic chains. The average value for fulvic acids (H:C)CORR is the equal to 2.4 (varying from 2.2 to 2.7), which shows the predominance of the saturated fragments in this structure. The predominant type of humus in the sediments is the humate one. It indicates that the process of the organic matter humification of sediment is dominant if compared to mineralization.