Studies of Volatile Organic Compounds Emission from Bottom Sediments of Mid–Forest Eutrophic Lake with the Use of Proton Transfer Reaction Mass Spectrometry

In 2023, studies were conducted on volatile organic compounds (VOCs) emitted from the bottom sediments of the mid-forest eutrophic lake. Lake Łętowskie is located in northern Poland and covers an area of 402 hectares. It is part of the “Łętowskie Lake and the vicinity of Kępice” Protected Landscape Area. Bottom sediment samples were collected from five sites located on the lake. The study sites differed in shoreline development: forest, agricultural land, and the central part of the lake. The emissions from the bottom sediment to the atmosphere of 20 volatile organic compounds were measured in the samples using a proton transfer reaction mass spectrometer (PTR-MS). This analytical technique enables the detection and determination of concentrations of volatile organic compounds characterized by proton affinity greater than that of water. The VOC data obtained showed different characteristics for study sites bordering forests and agricultural areas, which was supported by statistical analysis. The VOC data obtained from Lake Łętowskie were compared with results from neighboring lakes, demonstrating similarities to those observed in a lake with a forest catchment area.