Eco-Friendly and Green Biochar Sorbent–Extraction Techniques for Pharmaceuticals, Environmental, and Food Analysis—A Review

The most important aspect of sorbent-based approaches is the use of a sustainable, readily available, and cost-effective sorbent material for sample analysis. Biochar is an emerging and prominent sorbent material for various applications in sorbent-based techniques due to its availability, affordability, eco-friendly nature, porosity, pore structure, abundance of aliphatic and aromatic carbon structures, and abundant oxygen-containing functional groups. On the basis of the numerous benefits of biochar, this review discusses why biochar is the preferred sorbent in sorptive-based techniques. In addition, this review provides a brief evaluation of various biochar-based sorptive approaches, including biochar-based solid-phase extraction (SPE)/microextraction (SPME), magnetic SPE/SPME, in-tube SPME, pipette-tip micro SPE, and thin-film microextraction. Furthermore, each section briefly overviews various studies for various sample analyses and applications, including pharmaceuticals, environmental, and food. Most importantly, on the basis of the literature review, biochar is an emerging sorbent material for various sorbent-based techniques that require further investigation for various applications.