Application of Stir-Bar Sorptive Extraction for Determination of Organic Pollutants in Snow by Thermal Desorption Gas Chromatography—High-Resolution Mass Spectrometry

Abstract

Studying the chemical composition of snow as an indicator of atmospheric pollution at high latitudes is crucial for understanding the transport processes of pollutants in the atmosphere and assessing the anthropogenic impact on Arctic ecosystems. This study proposes a method for detecting and quantifying semi-volatile micropollutants in snow by combining stir-bar sorptive extraction (SBSE) with thermal desorption (TD) gas chromatography–high resolution mass spectrometry (Orbitrap). Optimizing of SBSE conditions using 76 test priority atmospheric pollutants allowed detection limits to be achieved for most non-polar and weakly polar semi-volatile compounds at the levels ranging from 0.01 to 1 ng L^–1. The method demonstrated the ability of detecting 62 analytes and achieving the highly sensitive determination of 32 analytes, with low labor costs using a minimum amount of sample (100 g). The SBSE-TD-GC–HRMS method for snow analysis was developed and validated. Tests on real samples from the Novaya Zemlya and Franz Josef Land archipelagos detected 29 pollutants from various classes, including polycyclic aromatic hydrocarbons, phenols, phthalates, nitro- and chloro-organic compounds, and their derivatives, with concentrations ranging from 0.1 to 50 ng kg^–1.