Deep eutectic solvents-based headspace single-drop microextraction for the chromatographic determination of phenols and aliphatic alcohols in atmospheric air

Abstract

In this work, the possibility for gas chromatography determination of volatile organic compounds in atmospheric air with preliminary microextraction into single drop of a deep eutectic solvent is presented for the first time. Highly toxic compounds (phenol, o-cresol) and aliphatic alcohols (methanol, n-butanol, n-pentanol) were selected as analytes for which low MPCs in the atmospheric air were established. A eutectic mixture of natural, environmentally friendly substances menthol and thymol was used as an extractant. The resulting eutectic solvent forms a stable drop that allows the rapid extraction of analytes from the gas phase. 30 min of sampling is enough to achieve sensitivity at the level of maximum permissible concentrations of these analytes in atmospheric air. At the same time, the volatility of the components of the eutectic compound themselves made it possible to introduce this solvent directly into the gas chromatograph without dilution. The developed procedure was used to analyze real air samples and standard gas mixtures. The limits of detection for analytes were in the range 0.001–0.01 mg L−1. The RSD for all analytes was <5 %. This sample preparation method can be easily and efficiently combined with subsequent chromatographic detection.