There is a trend in analytical chemistry towards development of eco-friendly methods of sample preparation without loss of efficiency. This book provides a general, critical, and updated vision of the different green sample preparation approaches that have been developed. These include miniaturisation of the extraction techniques that allow a reduction not only of the chemicals used during the process, but also of the sample amount; the use of greener solvents, such as certain ionic liquids (ILs) or deep eutectic solvents (DES), instead of conventional organic solvents; and the use of new selective sorbent materials that allow both extraction and clean-up in the same step. All of these strategies have been successfully applied to the determination of a wide variety of organic and inorganic compounds. Advanced undergraduate and graduate students will find this book a good reference source and, because of the multidisciplinary nature of this topic, it will be of use to a broad audience including chemists, materials scientists, environmental analysts, forensic scientists, pharmacists, biologists and chemical engineers, who are involved and interested in the future frontiers of analytical chemistry.