Moreover, this enhancement allows the use of a smaller amount of sorbent
compared to the conventional extraction approaches resulting in the saving of material. In order to obtain analytical in formation, the sorbent is then recovered after the extraction. The analytes can be directly monitorized on the sorbent surface by using a spectroscopic technique [22,23] or can be conveniently eluted/desorbed for the subsequent analysis of the eluted fraction [24–27]