Microwave Extraction of Semi-Volatile Organic Compounds from Soil

Introduction

Semi-volatile organic compounds (SVOCs) are a subgroup of volatile organic compounds (VOCs) that have high molecular weights and higher boiling points than VOCs. Among these compounds are polyaromatic hydrocarbons (PAHs), phthalates, plasticizers, polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs). Many of these compounds have been banned, due to both their persistence in the environment and human toxicity. Prolonged exposure to these compounds, especially indoors, has raised public health concerns, prompting their categorization by the US EPA as hazardous air pollutants (HAPs). Compounds under this categorization can cause serious health effects, such as allergies, asthma, endocrine and thyroid disruption, reproductive toxicity, fetal and child development delays, and even cancer.

SVOCs consist of compounds with diverse chemical properties and structural features. These differences make it challenging to efficiently extract all analytes of interest with one method. Furthermore, the soil matrix from which the SVOCs are to be extracted often include multiple components, adding to the complexity of extraction. With the MARS 6 running microwaveassisted solvent extraction (MASE), a batch of 40 samples with a difficult set of analytes can be effectively extracted from complex matrices.

Traditional methods, such as Soxhlet, are time consuming and use a large amount of solvent. Other automated methods often require tedious sample preparation and the assembly of complex sample holders. The MARS 6 is the only batch system available and uses a minimal amount of solvent. The MARSXpress or MARSXpress Plus vessels combined with disposable glass liners allows for simple and clean sample preparation.