The use of sorbents of various natures for the extraction of non-steroidal anti-inflammatory drugs from aqueous media (review)

Abstract

Non-steroidal anti-inflammatory drugs (NSAIDs) belong to the group of anti-inflammatory, analgesic, and antipyretic drugs and are among the most consumed pharmaceuticals by the global population. NSAIDs are characterised by side effects and biodegrade in the environment with the formation of the not less toxic compounds. Determination of non-steroidal anti-inflammatory drugs at the level of microconcentrations, even with the use of sensitive methods of analysis, is possible only after preliminary concentration. The purpose of this study was to summarize the use of sorbents of various natures (including those of natural origin) for the sorption of non-steroidal anti-inflammatory drugs based on international databases. Active carbons, biochar, materials based on graphene, carboxylated and uncarboxylated multilayer carbon nanotubes and other materials based on carbon (graphene-like carbon nitride, graphene oxide, chitosan, carbon nitride) are widely used for concentration. Nanostructured silicon and clay materials (CM), as well as nanoheterostructures based on CM are cost-effective, characterized by a mesoporous structure and a high surface area. For their modification, cationic surfactants and ionic liquids are used. In order to obtain a more developed surface and increase in the number of functional groups, it was proposed to activate sorbents by physical (thermal activation in a stream of gases) or chemical (use of inorganic acids, salts and alkalis) methods. Molecularly imprinted polymers were synthesized by precipitation and double imprinting processes, and crosslinked polymers and hybrid polymeric materials were synthesized by suspension-emulsion polymerization. Popular sorbents for the recovery of NSAIDs are magnetic nanosorbents and organometallic polymers. The review presents the sorption conditions (pH, solution volume, time to reach sorption equilibrium, sorbent mass), chemometric algorithms for optimizing the sorption conditions and the values of the limiting sorption of diclofenac, ibuprofen, and acetylsalicylic acid by materials of various natures. Possible sorption mechanisms, kinetic and sorption models, are described.