Dissolved methane in Lake Baikal: a modified technique for determining concentrations and vertical distribution in the water column

We have developed a modified method of headspace analysis of water samples with the control of temperature and total pressure in the gaseous phase of a closed heterogeneous system followed by a gas chromatographic measurement of methane concentration with the methane content in the lake water of < 500 nl СН4/L. Here, we describe the background concentrations and vertical distribution of dissolved methane in the water column of Lake Baikal, which were obtained for several years.