A 10,000 year record of sediment pore-water dissolved organic matter characteristics from Lake Peipsi as revealed by HPSEC

Abstract

In this study, high-performance size-exclusion chromatography (HPSEC) combined with diode-array detection (DAD) was applied for the investigation of dissolved organic matter (DOM) from sediment pore-water from Lake Peipsi, Estonia. The age of the 4 m long sediment core was estimated using the ¹⁴C dating method and suggested sediment accumulation for the past 10,000 years. Using the HPSEC approach it was possible to evaluate temporal changes in the content of DOM and its molecular weight characteristics during the Holocene period. The content of dissolved organic carbon (DOC) calculated from spectroscopic data was in good correlation with the total peak areas computed from HPSEC chromatograms. The results revealed that the content of detected DOC in the older samples 10,300 to 2,600 years before present (BP) was twice as high as in the younger ones (from 2,400 years BP to present). Thus, HPSEC analysis with spectroscopic methods might provide useful information about temporal changes in DOM content and could be used in palaeolimnological research.

Keywords:

• pore-water dissolved organic matter
• sediment
• HPSEC
• humic substances
• palaeolimnology
• Lake Peipsi

Acknowledgements

The support from the Estonian Science Foundation (Grant No. 6720) and the Estonian Ministry of Education and Research (target financing SF0332710s06) is gratefully acknowledged. This work has been partially supported by graduate school ‘Functional materials and processes’ receiving funding from the European Social Fund under project 1.2.0401.09-0079 in Estonia.