Pressurized liquid extraction of organic contaminants in environmental and food samples

Pressurized liquid extraction (PLE) is an automated technique that uses elevated temperature and pressure to achieve exhaustive extraction from solid matrices, so reducing solvent consumption and enhancing sample throughput when compared with traditional procedures. Hence, it can be considered an environment-friendly technique, generating small volumes of waste and reducing costs and time. This review focuses on application of this green technique to the analysis of organic contaminants in food and environmental matrices for monitoring purposes. We examine fundamentals and key aspects of the development of a PLE method, including pressurized hot-water extraction, together with some relevant applications in food and the environment. We pay special attention to methods, including clean-up in one step in the extraction cell or on-line clean-up coupled to the extraction cell. We also compare PLE with other techniques (e.g., Soxhlet, microwave-assisted extraction, and supercritical fluid extraction).