Green adsorbents and solvents in food analysis

Green analytical chemistry aims to minimize the negative impact of analytical procedures on the environment and human health. This can be achieved through the use of non-toxic and environmentally friendly reagents. Classical green solvents include water, ethanol, acetone, and supercritical fluids. Water has been used for the extraction of water-soluble compounds (sugars, amino acids). Ethanol and acetone have been used for the extraction of lipids and pigments, flavors and preparation of extracts for chromatographic analysis. Supercritical fluids have been used as a solvent in food analysis for the extraction of lipids, pigments, flavors and caffeine. In this chapter, new types of green solvents and their applications for food analysis have been described in detail. The description is given for new green solvents, for example, deep eutectic solvents (DESs), molecularly imprinted polymers (MIPs), ionic liquids, and supra molecular solvents. The application of these green solvents has been described in detail. The advantages and disadvantages associated with these green solvents have also been described in detail. In this chapter, we have summarized four types of green solvents and adsorbents as listed below molecularly imprinted polymers (MIPs), deep eutectic solvents (DESs), ionic liquids (ILs) and supramolecular solvents (SMs). Among the selected green solvents, ionic liquids (IL) have been extensively used for food analysis. The properties of IL can be adjusted by changing the composition of IL. Application of ionic liquids for metal analysis in foods has critically discussed. Deep eutectic solvents are a new class of green designer solvents with tunable properties and can be synthesized simply by mixing hydrogen bond donors (HBD) and hydrogen bond acceptors (HBA). Applications of DESs have been discussed in detail with special emphasis on the analysis of phenolic compounds, flavonoids and polar organic compounds. Molecularly imprinted polymer (IMPs) is an advanced class of greed adsorbent used for food analysis. A new class of green solvents “supramolecular solvents” has been discussed with special emphasis on supramolecular-deep eutectic solvents.