Analysis of environmental contaminants with molecularly imprinted polymers

Environmental pollutants affect negatively the environment, deteriorating the planet. The analysis of complex mixtures frequently requires several pretreatment steps and if the substance to be analyzed is present in low concentration, it needs to be concentrated so that it can be detected by standard analytical techniques. If it is a complex sample of similar compounds, a step is necessary that involves their cleaning. Solid-phase extraction is a widely used technique for sample pretreatment, since it is flexible and easy to automate. Molecularly imprinted polymers possess selective molecular recognition properties because the recognition sites within the polymer matrix are complementary to the molecule under analysis in the form and position of the functional groups. The molecular imprinting technique is based on the preparation of a highly cross-linked polymer around an analyte used as a template molecule, which is initially contacted with a suitable monomer in order to form a pre-polymerization complex and subsequently adds the cross-linker, the initiator and the solvent with which the polymerization is carried out. Once the polymer is obtained, the template molecule is extracted releasing the specific recognition sites. This paper presents a review of the molecular printing process and its applications in combination with solid phase extraction, to be used as an alternative for the pre-concentration of samples of environmental contaminants.