Abstract:

In the last years, the concept of Green Chemistry has emerged due to the need to implement new eco-friendly methodologies. The main objective of this recent way of doing chemistry is pollution prevention rather than remediation. For this purpose, twelve principles have been proposed to reduce or eliminate the generation of wastes or hazardous substances in the design, manufacture and application of chemical products. Green Chemistry represents a new philosophy and sets high standards to carry out research and production of chemical substances and processes, maximizing its benefits and minimizing the side effects that can be harmful to humans and the environment. Teaching Green Chemistry principles should also be part of any Chemistry related subject.

The role of Analytical Chemistry is not limited to the traditional field of analysis; indeed, it is currently contributing to the assessment of sustainable environmental chemistry. In this sense, the proposal of practical experiences that allow students to understand the importance of Analytical Chemistry as a mean of preventing environmental risks is an important issue.

The search for safer and cleaner extraction solvents that compile with Green Analytical Chemistry principles has led to the use of deep eutectic solvents (DESs) for extraction purposes -in particular in dispersive liquid-liquid microextraction (DLLME)- since a good number of them have a low or negligible toxicity and some of them are hydrophobic which can be used in DLLME without the addition of a dispersion solvent. Therefore, they are more environmentally friendly alternative solvents.

In the Master’s Degree in Chemistry of the University of La Laguna, several subjects provide students with the opportunity to practice new green methods by developing complete analytical methodologies in practical classes. As a result of this, they can improve their skills in the management and application of many of eco-friendly methods. Moreover, students achieve a current and sustainable point of view to face the resolution of problems in Analytical Chemistry.

In this work, we propose a particular quick and cheap strategy that can be easily developed in the laboratory, in which students have to prepare and characterise a natural DES (NADES) that compiles excellent characteristics to be used as a green solvent in the DLLME of a group of pollutants from different water samples. Results indicate that this approach clearly contributes to the knowledge and improvement of Green Chemistry principles and has an important effect on the future work of the students.

Keywords:

Green chemistry, natural deep eutectic solvent, eco-friendly, extraction, practical classes, learning by doing.