Grinstead and his co-workers [1-3] were the first to study extractants composed of an amine, an organic acid, and a diluent, all three components being water immiscible. They tested these extractants for extraction of CaCl2, MgCl2, NaCl, NaBr, NaNO3, and Na2SO4. Their studies were followed by those of other researchers [4-29], who investigated the extraction of many other salts, including chlorides and sulfates of many transition metals. Various names were used for these extractants, including amine salts, mixed extractants, mixed ionic solvents, and binary extractants. In the following, the term acid-base-coupled (ABC) extractants is used.
For a long time, scientists’ work had mainly focused on the improvement of methods for the diagnostic analysis of works of art. Although this is a really important topic, a huge demand for innovative solutions to solve the main issues in restoration was growing from conservators. We pioneered the application of nanoscience to the Conservation of Cultural Heritage, which may offer effective and exhaustive answers to these requests. In the following, we will highlight as case studies some of the most important methodologies developed.
