New materials in sample preparation: Recent advances and future trends

The low concentration levels of different chemical compounds in complex matrices such as food, environmental, biological and pharmaceutical, requires adequate analytical methods to isolate, preconcentrate and accurately quantify the analytes obtaining satisfactory results. The sample preparation step is a critical part of the whole analytical process, once it is constantly prone to contamination and at the same time, it is more difficult to automate. Aiming to improve the extraction performance of sample preparation techniques, highlighting the microextraction techniques, several sorbent materials have been developed and used in different application areas. They are based upon sorption processes and usually are in accordance with the principles of green chemistry (greener analytical methods). This review summarizes the recent advances and the prospects for new materials to be utilized in sample preparation techniques, emphasizing microextraction techniques based upon a sorption process in line with the concept of green analytical chemistry. We also approached the synthesis and main properties of the sorbent materials as well as the main miniaturized techniques that use them, and their most relevant and representative applications.