An investigation of polycyclic aromatic hydrocarbons (PAH) extraction using pressurized solvent techniques.

摘要

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in nature. They enter the environment through natural and anthropogenic sources, and can be persistent in the environment. PAHs are considered to be the first compounds known to be carcinogenic, and therefore numerous studies have been conducted focusing on the detection, analysis and remediation of these organic pollutants. Due to their chemical and physical properties, the results of PAH analysis using commercial pressurized solvent extraction (PSE) instrumentation are often variable, with errors of greater than 50% expected and accepted. The present project has extensively investigated the PSE extraction of PAHs in solid matrices. These studies suggested that PAHs were being retained in the PSE extraction cells by a physical bond between the cell frit and the analytes, causing unreliable surrogate and analyte recoveries. An improved extraction method, including the silanization of the extraction cell frits using 15% dichlorodimethylsilane in toluene, was developed. This method improved the surrogate and analyte recoveries of all PAHs, with improved accuracy and precision at concentrations as low as 20 ng·g-1. This method was validated using Ottawa sand, dry soil, and soil with varying moisture contents. A detection limit of less than 5 ng·g-1 was achieved for all PAHs studied, in accordance with the Sediment Quality Guidelines outlined by the Canadian Council for the Ministers of the Environment.;Key words. polycyclic aromatic hydrocarbons, pressurized solvent extraction, GC-MS, silanization