An overview on the recent applications of agarose as a green biopolymer in micro-extraction-based sample preparation techniques.

Introducing a myriad array of chemicals in different industrial fields has made sample preparation inevitable for trace analysis. Classical extraction techniques such as solid phase extraction (SPE) and liquid-liquid extraction (LLE) techniques often suffer from tedious procedures (huge workload) and hazards to personnel and environment (samples and reagents are often user-unfriendly and processed in high amounts). For addressing these problems, microextraction techniques have been introduced. These systems benefit from using a minute amount of sample, reduced consumption of organic solvents, enhanced clean-up, high recovery and high enrichment factors. Moreover, approaches based on the use of natural materials have emerged during the last 10 years. Agarose is a natural biopolymer used as a green material in the form of gel-based separation medium. It has been recently utilized in the microextraction schemes. Easy fabrication, adjustability to get various dimensions and shapes, high inertness and biodegradability are of its main attributes. The present overview is focused on applications of agarose in solid phase microextraction (SPME), micro-solid phase extraction (μ-SPE) and liquid phase microextraction (LPME) - agarose film-liquid phase microextraction (AF-LPME) and gel electromembrane extraction (G-EME) since 2012. Besides, the pros and cons of agarose employment in the mentioned techniques will be described in depth.