ISSN 00978078, Water Resources, 2013, Vol. 40, No. 3, pp. 285–296. © Pleiades Publishing, Ltd., 2013. Original Russian Text © N.S. Safronova, E.S. Grishantseva, G.S. Korobeinik, 2013, published in Vodnye Resursy, 2013, Vol. 40, No. 3, pp. 274–286. WATER QUALITY AND PROTECTION: ENVIRONMENTAL ASPECTS Hydrocarbon Gases (C1–C5) and Organic Matter in Bottom Sediments of the Ivankovo Reservoir on the Volga River N. S. Safronovaa, E. S. Grishantsevaa, and G. S. Korobeinikb a Moscow State University, Moscow, 119991 Russia Email:
[email protected] b Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, ul. Kosygina 19, GSP1, Moscow, 119991 Russia Received June 21, 2011 Abstract—The results of studying the composition of hydrocarbon gases (C1–C5) and organic matter in bot tom sediments of the Ivankovo Reservoir in 1995, 2004, and 2005 are given. The methods used in the study include vaporphase gas chromatography, instrumental pyrolysis gas chromatography, and massspectrom 13 etry for determining organic carbon δ Corg. The gas field of bottom sediments in different regions of the res ervoir varies widely in terms of gas saturation and the spectrum of hydrocarbon gases. This suggests the het erogeneous composition of organic matter in the sediments and different conditions of its input and transfor mation processes. The gases were found to contain saturated hydrocarbons from methane to pentane C1–C5, including isomers iC4 and iC5 and unsaturated compounds C2–C4. A correlation was found to exist between methane distribution and the distribution of its more highmolecular homologues, which confirms their genetic relationship in bottom sediments.