Automation The use of various elements of an analytical process with minimal or reduced human intervention. Direct analysis The analysis of a sample without any sample treatment. Eco-scale Quantitative criterion to evaluate method greenness. Greenness Environmental impact of an analytical methodology. Life cycle assessment A technique to evaluate the environmental impacts associated with all the steps of a procedure. Miniaturization The scaling down of mechanical, optical and electronic devices and analytical operations. Passivation The change of chemical form or hazard reagent or waste to reduce its reactivity or toxicity. Sensor A device employed to detect changes in its environment and send the information to an electronic processor.

Green Analytical Chemistry and Green Chemistry

Since the 1970s decade, novel analytical methodologies have been introduced to improve the analytical figures of merit of previous methods, and also to reduce the undesirable side effects, like operator risk, environment contamination, consumption of reagents and solvents, waste generation, and so on. In this sense, different strategies were considered to improve analytical methods based on automation, miniaturization, direct and multianalyte analysis, and reduction of solvents, reagents and wastes together with the replacement of toxic reagents by innocuous ones, as it can be seen in Fig. 1 that shows the progress on the concepts related with green analytical chemistry and the main milestones since the 1970s. The increasing environmental conscience of analytical chemistry was firstly introduced as “Ecological Paradigm” by Malissa, in 1987, indicating that today Analytical Chemistry must be closely implicated in the preservation of our ecosystem and actively contribute to the protection of the environment and the operator safety. De la Guardia and Ruzicka in 1995 edited the first international scientific journal issue devoted to sustainable methods and introduced the “Environmentally Friendly Analytical Chemistry” concept, based on the replacement or reduction of toxic chemicals to harmless ones by the incorporation of (i) robotics, (ii) miniaturized chromatograph systems, (iii) flow techniques as flow injection analysis or sequential injection analysis, and (iv) sensor technologies. Green Chemistry concept was introduced by Anastas and Warner in 19981 indicating the environmental implication in the development of chemical products and processes. Thus, Green Chemistry must contribute to avoid, or reduce, the negative impacts of chemical activities on human health and the environment. This concept is based on (i) the reduction of reagent and solvent consumption, (ii) the reduction of wastes, (iii) the proposal of recycling, passivation or degradation of toxic wastes, and (iv) the use, if possible, of remote sensing and direct analysis of samples without treatment. The 12 Principles of Green Chemistry were proposed as a list of guidelines to conduct in order to make more environmentally sustainable (greener) a chemical, process or product. They were summarized under the acronym PRODUCTIVELY and emphasized aspects like atom economy, toxicity of reagents, energetic efficiency, or method safety. The “integrated environmentally friendly approach” was proposed by de la Guardia in 1999 based on the evaluation of the whole analytical process in the frame of the ecological paradigm in order to preserve accuracy, sensitivity and selectivity of the analytical method, but also reducing cost and sample handling, and improving operator safety and comfort, repeatability, and laboratory productivity. To achieve this, the use of strategies based on in-field sampling, on-line analysis, and on line decontamination/passivation of wastes was proposed. Green Analytical Chemistry was introduced by Anastas in 1999 and deeply discussed in the books of Koel and Kaljurand, and de la Guardia and Armenta. Green Analytical Chemistry combines in a unique frame all the aforementioned strategies. The reduction of reagent and solvent consumptions must be mainly directed to the steps of the analytical process, such as sample extraction and preparation, and analyte separations. Automation and minimization of analytical methods allows the reduction of both, reagents and generated wastes. Additionally, special efforts must be focused in the development of direct methodologies for the in-field, noninvasive and remote analysis. Green Analytical Chemistry does not limit the progress of novel analysis methods, but compromises them with the preservation of the environment. The history of Green Chemistry and Green Analytical Chemistry concepts has run in parallel since their formulation. However, from the 12 Principles of Green Chemistry, only few are applicable to analytical chemistry approaches, such as: (i) prevention of wastes, (ii) use of safe and not toxic reagents and solvents, (iii) increase energy efficiency, and (iv) avoid derivatization steps. The objectives and needs of an analytical method slightly differ from those of general chemistry and, consequently, additional principles related to Green Analytical Chemistry were required. Thus, Galuzska et al.2 enunciated the 12 Principles of Green Analytical Chemistry, under the acronym SIGNIFICANCE, introducing aspects as the use of chemometric data treatment to reduce number of samples, the use of integrated systems to improve efficiency, use of natural solvents, or the incorporation of miniaturized systems.