Preface Free

When analytical chemists are asked, “What is the battle horse of any analytical method?”, in all probability, a higher percentage of them would surely point to “sample preparation”…

The first attempts in this field introduced so-called “classical extraction methods”: a high number of efficient sample preparation procedures that soon evolved and consolidated in the scientific community worldwide, but that in the end turned out to be tedious and time consuming. At a certain point, sample preparation moved towards a completely new horizon: miniaturization and automation. It was clear that, in many cases, only extremely low amounts of samples were available, and that enormous quantities of materials and solvents as well as time and, therefore, money, were also wasted unnecessarily, as experiments had shown. As a result, Analytical Chemistry can currently rely on many highly efficient solvent- and sorbent-based microextraction procedures, some of them also automated, most of which are highly consolidated nowadays.

However, in the last few years a new horizon, in parallel and related to that of miniaturization and automation, has also been established: the achievement of green sample preparation procedures, a greenness that can also be accomplished together with miniaturization, and that is a clear trend in the Analytical Chemistry field that is being constantly implemented.

Starting with an introductory chapter on this specific topic, as well as the second one on miniaturization and automation, without which green sample preparation cannot be understood, this book reviews the different extraction materials (i.e. metal– and covalent–organic frameworks, carbonaceous materials, molecularly imprinted polymers, natural sorbents) and solvents (i.e. ionic liquids, deep eutectic solvents, supramolecular solvents, switchable hydrophilicity solvents) used to achieve greenness in sample preparation; some of them are green per se, while others contribute to achieving such a final goal. Finally, several chapters devoted to environmental, food, and pharmaceutical applications have also been introduced, in order to clearly show and demonstrate the high potential and applicability of such approaches, which are daily growing.

As editors, we would like to thank all the authors that have kindly agreed to contribute to this challenging and, at the same time, revulsive project. We both know that, like both of us, they strongly believe in the importance of walking, hand by hand, towards the achievement of sustainable sample pretreatment procedures and, in general, towards the accomplishment of sustainable analytical methodologies, in accordance with sustainable development goals.

Javier Hernández-Borges

Chaudhery Mustansar Hussain