Green solvents for sample preparation in analytical chemistry

An analytical procedure comprises two steps: sample preparation mostly extraction (Soxhlet, Dean-Stark, Likens-Nickerson, Blye & Dyer, Folch, leaching, maceration, percolation) and analysis (spectrophotometry, chromatography, spectrometry). Whereas chemical analysis is finished after few minutes, extraction takes at least several hours and requires large solvent volumes, energy-consuming for concentration step by evaporation to recover the final extract. In this current opinion we provide an instantaneous picture of current knowledge on alternative and green solvents used in analytical laboratories for sample preparation and extraction of natural product in terms of innovation, original procedures, and safe products. We discussed how bio-based solvents, water in different forms, deep eutectic solvents, liquefied gas have already become an important issue in the sample preparation in analytical chemistry of natural products replacing petroleum and hazardous solvents.