New hydrophilic materials for solid-phase extraction

Solid-phase extraction (SPE) is increasingly being used as a sample pre-treatment technique to cover a wide range of analytes, including the most polar. This involves the development of new sorbents that are able to trap the most polar analytes. We provide an overview of the new sorbents, both commercially available and synthesized in-house, which improve the extraction of the most polar compounds in SPE. We mainly cover polymeric sorbents with a large specific surface area and a hydrophilic character that is obtained by either copolymerizing polar monomers or introducing polar functional groups. Other novel material technology, such as monoliths, is also described. For these new sorbents, we describe morphological and chemical properties that we relate to their retention capabilities towards polar compounds. We discuss the recoveries of polar compounds when these sorbents are used in SPE and compare them with recoveries when other sorbents are used. (c) 2005 Elsevier Ltd. All rights reserved.