Microextraction Tech

Cyclodextrins (CDs) are cyclic (R-1,4)-linked oligosacharides that consist of 6 (α- CD), 7 (β-CD) or 8 (γ-CD) glucopyranose subunits. They present a characteristic cage-like structure which allows to host molecules that present an appropriate dimension and polarity (Figure 1). In fact, the supramolecular structure posses an hydrophilic external surface and a hydrophophic cavity which make cyclodextrins useful to dissolve non-polar compounds in polar environments. The non-polar compounds form inclusion complexes with the cyclodextrin cavities involving non-covalent bonds which makes this interaction reversible.   Figure 1. Chemical and conformation structures of  γ-CD    The dimensions of cyclodextrins are defined in terms of outer diameter, cavity diameter, height of torus and cavity volume (Figure 2). These dimensions depend directly on the number of glucopyranose subunits and mark the type of analytes that are able to enter in the cavity to form an inclusi...