Task-specific ionic liquids: Applications in sample preparation and the chemistry behind their selectivity

•Review of the last ten years of task-specific ionic liquids (TSILs) applications for sample preparation, covering practically of their history in this field.•Applications on TSILs for preparation and treatment of environmental, food and beverages and biological samples are reviewed and analyzed in terms of their analytical characteristics.•Special emphasis is made on the chemistry responsible for the selectivity of TSILs, and the structural reasons behind their specificity.