Evaluation of the Functional State of Marsh Ecosystems in Belarus and in West Siberia on the Basis of Analysis of Peatr Bitumen Composition
O. V. SEREBRENNIKOVA1,2, E. B. STRELNIKOVA1, M. A. DUCHKO1, N. G. AVERINA3, and N. V. KOZEL3
1Institute of Petroleum Chemistry, Siberian Branch of the Russian Academy of Sciences, Pr. Akademicheskiy 4, Tomsk 634021 (Russia)
2National Research Tomsk Polytechnical University, Pr. Lenina 30, Tomsk 634050 (Russia)
3Institute of Biophysics and Cell Engineering, National Academy of Sciences of Belarus, Ul. Akademicheskaya 27, Minsk 220072 (Belarus)
Keywords: торф, битум, ГХ-МС, алифатические соединения, терпены, стероиды, каротиноиды, тетрапирролы, peat, bitument, GC-MS, aliphatic compounds, terpenes, steroids, carotenoids, tetrapyrrholes
Abstract
More than 150 compounds represented by n- alkanes, n- alkane-2-ones, n- aldehydes, fatty acids and their esters, as well as isoprenoids including sesqui-, di-, triterpenes, steroids, acyclic compounds and tocopoherols were identified in the chloroform-methanol extract of high-moor and valley peat from native, unwatered and recovered regions of marshes in Belarus and in West Siberia by means of gas chromatography - mass spectrometry The composition of carotenoids and tatrapyrrhole pigments was determined in the acetone extract of peat by means of high-pressure liquid chromatography in combination with absorption spectroscopy. Chlorofyll a and b, pheophytin a and b, pheophorbide a, bacteriopheophytin b, lutein, α-carotene and neoxanthine were identified. It was demonstrated that the compounds undergoing the most substantial qualitative and quantitative changes during dewatering are sesqui-, di- and triterpenes, steroids, as well as carotenoids and tetrapyrrholes. Unlike for unaffected peat beds, the dominating sesquiterpene in all the studied high-moor and valley peat samples from dewatered and recovered regions is β-cadinene; the derivatives of lanosterol are present among steroids; in dewatered and recovered valley peat of Belarus there are des-A-derivatives of oleane structures, while among triterpenoids of dewatered peat from West Siberia there are oxygen-containing hopanoids. As a consequence of dewatering, chlorophylls disappear from peat pigments, while the concentration of neoxanthine increases. Dienic pentacyclic structures are absent from dewatered and recovered high-moor peat in Belarus, while the overall fraction of hopanoids increases. As a result of repeated watering of dewatered regions of upland bogs in Belarus, betulin and b-amirin appear among five-membered cyclic isoprenoids. Similarly to native peat, keto derivatives of hopene and oleanene are detected in those samples, while these compounds are absent from peat in dewatered region. The differences in the changes of the individual composition of triterpenes accompanying bog dewatering in West Siberia and Belarus may be due to more severe clinmatic conditions and, as a consequence, low rate of oxidative processes taking place in peat deposit. The obtained results may poromote deeper understanding of the processes that take place in peat deposits, prediction of the development of peat marsh ecosystems and reasonable use of peat.
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