Biopolymers in sorbent-based microextraction methods

Since the introduction of the Green Analytical Chemistry guidelines, there has been an increasing concern on the sustainability of sample preparation approaches, particularly if considering they constitute the most time-consuming step of the analytical method and the main source of laboratory wastes. Among the alternatives explored, it is important to highlight the miniaturization of the extraction methods, which has been accompanied by the seek of greener solvents and sorbents. Biopolymers emerge as potential candidates to be used as sorbents in microextraction schemes given their biodegradability, versatility, and easily functionalization. This review offers an overview on biopolymers (chitosan, cellulose, alginate, and agarose) in sorbent-based microextraction approaches, paying attention to the preparation of the sorbent and the format in which biopolymers are incorporated into the sorbent/device, thus implying a specific microextraction approach, their role in the resulting sorbent material, and the reported analytical applications, covering environmental, food, and bioclinical analysis.