QuEChERS Extraction of PAHs from Various Soils and Sediments Followed by Chromatographic Determination

Abstract

We studied the features of PAHs extraction by QuEChERS in the sample preparation of soils and bottom sediments of various compositions followed their determination by gas chromatography–mass-spectrometry. The test samples were soils of sandy, loamy sand, loamy, and clayey types and bottom sediments of loamy sand type. The mineralogical composition and organic matter content of the samples were used to predict how PAHs were retained by the soils and sediments. The impact of ultrasonic treatment on analyte extraction with subsequent identification by chromatography was assessed. No ultrasonic treatment was required to extract and determine all PAHs (up to 100%) in sandy and loamy sand soils and low-molecular-weight PAHs in all test samples. The QuEChERS extraction and determination of high-molecular-weight PAHs in clay type soil samples and loamy sand bottom sediments required a 10-min ultrasonic treatment, while the recoveries of analytes were higher than 87 and 90%, respectively. The analysis of a loamy soil sample with a high organic matter content was the most challenging. To extract over 70% of high-molecular-weight PAHs from a sample of this type using the QuEChERS technique, the binary acetonitrile–acetone (1 : 1) extractant rather than conventional acetonitrile was used with the simultaneous 15-min ultrasonic treatment.