Известия Томского политехнического университета: Инжиниринг георесурсов (May 2019)
The composition of peat extracts from drained and natural raised bogs of Belarus and Western Siberia
Abstract
Relevance of the work is caused by the active reclamation of swamps and the lack of data on wetland drainage impact on chemical composition of peat deposits. The main aim of the study is to characterize composition of peat extracts from natural and drained peat bogs in Belarus and Western Siberia. The methods used in the study: high performance liquid chromatography, UV-spectrometry, chromatography-mass spectrometry. Results: Using GC/MS the authors have identified more than 150 compounds represented by n-alkanes, n-alkan-2-ones, n-aldehydes, fatty acids and their esters, as well as isoprenoids, comprising sesqui-, di, triterpenes, steroid compounds, acyclic and tocopherols in the chloroform-methanol extract of native upland and drained peat Belarus and Western Siberia. The composition of carotenoid and tetrapyrrole pigments was determined in peat acetone extract by high pressure liquid chromatography in combination with electron spectroscopy. Among the pigments chlorophylls a and b, pheophytin a and b, pheophorbide, lutein and neoxanthin were identified. It is shown that the highest sesqui-, di-and triterpenes, steroids, and carotenoids and tetrapyrroles undergo qualitative and quantitative changes when drying. As a result of drainage in peat raised bogs of Belarus the amount of steroids, sesqui- and diterpenes increased, in peats of Western Siberia - the amount of steroids, terpenes and tocopherols. Among the steroids the content of lanostan derivatives increased. As a result of drainage chlorophyll disappeared and neoxanthipart amount increased in peat in pigment composition. The difference in the climatic conditions of Western Siberia and Belarus found its way in changes while drying swamps of individual terpenes. Later periods of thawing, especially marshes drained sites, and discharge of meltwater in Western Siberia create less favorable conditions for drying and cause low speed of oxidation occurring in peat deposits. As a result, in drained Belarus peat the variety of terpenes decreased significantly due to destruction of the least stable compounds, while in peats of Western Siberia these compounds are preserved.
