AGREE-Analytical GREEnness Metric Approach and Software

Green analytical chemistry focuses on making analytical procedures more environmentally benign and safer to humans. The amounts and toxicity of reagents, generated waste, energy requirements, the number of procedural steps, miniaturization, and automation are just a few of the multitude of criteria considered when assessing an analytical methodology’s greenness. The use of greenness assessment criteria requires dedicated tools. We propose the Analytical GREEnness calculator, a comprehensive, flexible, and straightforward assessment approach that provides an easily interpretable and informative result. The assessment criteria are taken from the 12 principles of green analytical chemistry (SIGNIFICANCE) and are transformed into a unified 0–1 scale. The final score is calculated based on the SIGNIFICANCE principles. The result is a pictogram indicating the final score, performance of the analytical procedure in each criterion, and weights assigned by the user. Freely available software makes the assessment procedure straightforward. It is open-source and downloadable from https://mostwiedzy.pl/AGREE.

Ionic liquids and deep eutectic mixtures: sustainable solvents for extraction processes

In recent years, ionic liquids and deep eutectic mixtures have demonstrated great potential in extraction processes relevant to several scientific and technological activities. This review focuses on the applicability of these sustainable solvents in a variety of extraction techniques, including but not limited to liquid- and solid-phase (micro) extraction, microwave-assisted extraction, ultrasound-assisted extraction and pressurized liquid extraction. Selected applications of ionic liquids and deep eutectic mixtures on analytical method development, removal of environmental pollutants, selective isolation, and recovery of target compounds, purification of fuels, and azeotrope breaking are described and discussed.

How green are ionic liquids? - A multicriteria decision analysis approach

Due to various desirable physicochemical properties, ionic liquids (ILs) are still gaining in popularity. ILs have been recurrently considered green solvents. However, environmental, health and safety assessments of ILs have raised certain doubts about their benignness, and their greenness status is currently unclear. To clarify the situation on their greenness, we perform a comprehensive assessment of more than 300 commercially available ILs. We apply multicriteria decision analysis, the tool that allows ranking many alternatives according to relevant criteria. They are toxicity towards various organisms, biodegradability, hazard statements and precautionary measures during their handling. We incorporated organic solvents to rankings, as their greenness is better described, so they serve as greenness reference points. The ranking results obtained considering the whole set of criteria show that ILs are placed between recommended polar solvents and problematic/undesirable non polar organic solvents in terms of greenness. However, the exclusion of toxicity data due to unavailability of endpoints results in assessment of ILs as greener than most of organic solvents.

Paper-based analytical device for instrumental-free detection of thiocyanate in saliva as a biomarker of tobacco smoke exposure

This work describes a fast and simple assay for in situ detection of thiocyanate, i.e., a biomarker of tobacco smoke exposure, in human saliva. The assay is based on the formation of an iron(III)-thiocyanate colored complex in a paper-based sensing platform and subsequent image analysis using a scanner as detection device. Experimental parameters influencing the color intensity of the complex were fully evaluated, including the selection of detection conditions, type of paper substrate, test zone dimensions and composition as well as the stability of the paper-based device. Under optimal conditions, the detection limit was 0.06mM of thiocyanate, and the repeatability, expressed as relative standard deviation, was 3%. The proposed method, characterized by its simplicity, portability and low sample consumption, was applied to the detection of thiocyanate in a series of human saliva samples. Average thiocyanate levels in the ranges 0.28-0.87mM and 0.78-4.28mM were found for non-smokers and smokers, respectively. Recovery studies were carried out at two concentration levels, showing recovery values in the range of 96.1-103.6%.

Miniaturized analytical methods for determination of environmental contaminants of emerging concern - A review

The determination of contaminants of emerging concern (CECs) in environmental samples has become a challenging and critical issue. The present work focuses on miniaturized analytical strategies reported in the literature for the determination of CECs. The first part of the review provides brief overview of CECs whose monitoring in environmental samples is of particular significance, namely personal care products, pharmaceuticals, endocrine disruptors, UV-filters, newly registered pesticides, illicit drugs, disinfection by-products, surfactants, high technology rare earth elements, and engineered nanomaterials. Besides, an overview of downsized sample preparation approaches reported in the literature for the determination of CECs in environmental samples is provided. Particularly, analytical methodologies involving microextraction approaches used for the enrichment of CECs are discussed. Both solid phase- and liquid phase-based microextraction techniques are highlighted devoting special attention to recently reported approaches. Special emphasis is placed on newly developed materials used for extraction purposes in microextraction techniques. In addition, recent contributions involving miniaturized analytical flow techniques for the determination of CECs are discussed. Besides, the strengths, weaknesses, opportunities and threats of point of need and portable devices have been identified and critically compared with chromatographic methods coupled to mass chromatography. Finally, challenging aspects regarding miniaturized analytical methods for determination of CECs are critically discussed.

Directly suspended droplet microextraction in combination with microvolume UV-vis spectrophotometry for determination of phosphate

A miniaturized methodology for the determination of phosphate in waters has been developed by combining directly suspended droplet microextraction (DSDME) with microvolume spectrophotometry. The method is based on the extraction of the ion pair formed between 12-molybdophosphate and malachite green onto a microdrop of methyl isobutyl ketone and subsequent spectrophotometric determination with no dilution. An enrichment factor of 325 was obtained after 7.5 min of microextraction. The detection limit was 6.1 nM phosphate and the repeatability, expressed as relative standard deviation, was 2.7% (n=6). The method was successfully applied to the determination of dissolved reactive phosphorus in different freshwater samples.

Rapid screening of polycyclic aromatic hydrocarbons (PAHs) in waters by directly suspended droplet microextraction-microvolume fluorospectrometry

A rapid and simple screening method for polycyclic aromatic hydrocarbons (PAHs) in water samples is proposed. The method is based on the combination of a miniaturized sample preparation approach, namely, directly suspended droplet microextraction (DSDME), and microvolume fluorospectrometry. Benzo[a]pyrene (BaP) was used as the model compound for screening purposes. Under optimal conditions, a detection limit of 0.024 μg L(-1) and an enrichment factor of 159 were obtained for BaP in 5 min. The repeatability, expressed as relative standard deviation (RSD), was 4.9% (n=8). The unreliability region of the screening method was 0.54-0.67 μg L(-1), by using a cut-off value of 0.6 μg L(-1) of BaP. Finally, the proposed method was applied to the in situ achievement of the binary "yes/no" response for PAHs in different water samples and recovery studies were performed at three different levels, with BaP recoveries in the range of 93-104%.

Ionogel fibres of bis(trifluoromethanesulfonyl)imide anion-based ionic liquids for the headspace solid-phase microextraction of chlorinated organic pollutants

A procedure for the immobilization of different ionic liquids on a SPME fibre was developed and optimized. A hybrid sorbent was successfully applied for the isolation of chlorinated organics from water samples.