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4 pages, 176 KiB

Open AccessEditorial

Development of Alternative Green Sample Preparation Techniques

by Emanuela Gionfriddo

Separations 2020, 7(2), 31; https://doi.org/10.3390/separations7020031 - 4 Jun 2020

Cited by 7 | Viewed by 3102

Abstract

Although chemistry disciplines are often regarded by the public as polluting sciences, in the last three decades, the concept of “Green Chemistry” has fueled the development of more sustainable and environmentally friendly chemical processes that are mainly aimed at minimizing the production of [...] Read more.

Although chemistry disciplines are often regarded by the public as polluting sciences, in the last three decades, the concept of “Green Chemistry” has fueled the development of more sustainable and environmentally friendly chemical processes that are mainly aimed at minimizing the production of toxic laboratory waste, to maximize pollution prevention [...] Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

Research

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15 pages, 3554 KiB

Open AccessArticle

Automation of µ-SPE (Smart-SPE) and Liquid-Liquid Extraction Applied for the Analysis of Chemical Warfare Agents

by Marc André Althoff, Andreas Bertsch and Manfred Metzulat

Separations 2019, 6(4), 49; https://doi.org/10.3390/separations6040049 - 9 Oct 2019

Cited by 6 | Viewed by 5195

Abstract

Existing autosamplers are frequently applied only for subjecting the samples to the instruments for injection. In our study, we have set up a TriPlusRSH autosampler mounted on a GC-FID-MS/MS system using the new Method Composer and Script Editor software to automatize all necessary [...] Read more.

Existing autosamplers are frequently applied only for subjecting the samples to the instruments for injection. In our study, we have set up a TriPlusRSH autosampler mounted on a GC-FID-MS/MS system using the new Method Composer and Script Editor software to automatize all necessary sample preparation steps and subsequent injection of samples in the field of chemical disarmament. Those include but are not limited to: liquid-liquid extraction, drying steps, solvent exchange, and µ-SPE. Tedious and error prone off-line steps are eliminated. In particular, when investigating highly toxic substances like chemical warfare agents or anticancer drugs, automation can help to minimize health risks for lab personnel. The setup engaged features brand new prototype equipment, e.g., a centrifuge to assist in phase separation for liquid-liquid extraction. Efficiency and accuracy of the automated methods were carefully evaluated and proven to outperform the respective manual steps after optimization, e.g., the processing time is up to 60% faster and recovery rates are doubled. The developed workflows can easily be adapted to other sample preparation protocols, e.g., determination of octanol/water partition coefficients, and be used amongst different instruments and chromatography data handling systems. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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16 pages, 1793 KiB

Open AccessFeature PaperArticle

A Bottom-Up Approach for Data Mining in Bioaromatization of Beers Using Flow-Modulated Comprehensive Two-Dimensional Gas Chromatography/Mass Spectrometry

by Andre Cunha Paiva, Daniel Simões Oliveira and Leandro Wang Hantao

Separations 2019, 6(4), 46; https://doi.org/10.3390/separations6040046 - 25 Sep 2019

Cited by 20 | Viewed by 4745

Abstract

In this study, we report the combination of comprehensive two-dimensional gas chromatography (GC×GC) with multivariate pattern recognition through template matching for the assignment of the contribution of Brazilian Ale 02 yeast strain to the aroma profile of beer compared with the traditional Nottingham [...] Read more.

In this study, we report the combination of comprehensive two-dimensional gas chromatography (GC×GC) with multivariate pattern recognition through template matching for the assignment of the contribution of Brazilian Ale 02 yeast strain to the aroma profile of beer compared with the traditional Nottingham yeast. Volatile organic compounds (VOC) from two beer samples, which were fermented with these yeast strains were sampled using headspace solid-phase microextraction (HS-SPME). The aroma profiles from both beer samples were obtained using GC×GC coupled to a fast scanning quadrupole mass spectrometer. Data processing performed through multiway principal components analysis succeeded in separating both beer samples based on yeast strain. The execution of a simple and reliable procedure succeeded and identified 46 compounds as relevant for sample classification. Furthermore, the bottom-up approach spotted compounds found exclusively in the beer sample fermented with the Brazilian yeast, highlighting the bioaromatization properties introduced to the aroma profile by this yeast strain. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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11 pages, 1156 KiB

Open AccessFeature PaperArticle

Determination of Hydrophilic UV Filters in Real Matrices Using New-Generation Bar Adsorptive Microextraction Devices

by Alessandra Honjo Ide and José Manuel Florêncio Nogueira

Separations 2019, 6(4), 45; https://doi.org/10.3390/separations6040045 - 25 Sep 2019

Cited by 9 | Viewed by 2965

Abstract

In the present contribution, new-generation bar adsorptive microextraction devices combined with microliquid desorption, followed by high-performance liquid chromatography–diode array detection (BAµE-µLD/HPLC–DAD) are proposed for the determination of two very polar ultraviolet (UV) filters (2-phenylbenzimidazole-5-sulfonic acid (PBS) and 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BZ4)) in aqueous media. [...] Read more.

In the present contribution, new-generation bar adsorptive microextraction devices combined with microliquid desorption, followed by high-performance liquid chromatography–diode array detection (BAµE-µLD/HPLC–DAD) are proposed for the determination of two very polar ultraviolet (UV) filters (2-phenylbenzimidazole-5-sulfonic acid (PBS) and 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BZ4)) in aqueous media. Different sorbents were evaluated as BAµE coating phases, in which polystyrene–divinylbenzene polymer showed the best selectivity for the analysis of both UV filters, with average extraction efficiency of 61.8 ± 9.1% for PBS and 69.5 ± 4.8% for BZ4. The validated method showed great reproducibility for the analysis of PBS and BZ4 UV filters, providing suitable limits of detection (0.04 µg L⁻¹ and 0.20 µg L⁻¹), as well as good linear dynamic ranges (0.16–16.0 and 0.8–80.0 µg L⁻¹), respectively. The proposed methodology was applied for monitoring the target analytes in several real matrices, including tap, sea, and estuarine waters, as well as wastewater samples. Despite some matrix effects being observed for some real samples, good selectivity and linearity were obtained. The present contribution showed an innovative analytical cycle that includes the use of disposable devices, which make BAµE much more user-friendly and suitable for the routine work, being a remarkable analytical alternative for trace analysis of priority compounds in real matrices. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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16 pages, 1010 KiB

Open AccessArticle

Optimised Extraction of Trypsin Inhibitors from Defatted Gac (Momordica cochinchinensis Spreng) Seeds for Production of a Trypsin Inhibitor-Enriched Freeze Dried Powder

by Anh V. Le, Sophie E. Parks, Minh H. Nguyen and Paul D. Roach

Separations 2019, 6(1), 8; https://doi.org/10.3390/separations6010008 - 5 Feb 2019

Cited by 5 | Viewed by 3973

Abstract

The seeds of the Gac fruit, Momordica cochinchinensis Spreng, are rich in trypsin inhibitors (TIs) but their optimal extraction and the effects of freeze drying are not established. This study aims to (1) compare aqueous solvents (DI water, 0.1 M NaCl, 0.02 M [...] Read more.

The seeds of the Gac fruit, Momordica cochinchinensis Spreng, are rich in trypsin inhibitors (TIs) but their optimal extraction and the effects of freeze drying are not established. This study aims to (1) compare aqueous solvents (DI water, 0.1 M NaCl, 0.02 M NaOH and ACN)/water/FA, 25:24:1) for extracting TIs from defatted Gac seed kernel powder, (2) to optimise the extraction in terms of solvent, time and material to solvent ratio and (3) to produce a TI-enriched freeze-dried powder (FD-TIP) with good characteristics. Based on the specific TI activity (TIA), the optimal extraction was 1 h using a ratio of 2.0 g of defatted powder in 30 mL of 0.05 M NaCl. The optimisation improved the TIA and specific TIA by 8% and 13%, respectively. The FD-TIP had a high specific TIA (1.57 ± 0.17 mg trypsin/mg protein), although it also contained saponins (43.6 ± 2.3 mg AE/g) and phenolics (10.5 ± 0.3 mg GAE/g). The FD-TIP was likely stable during storage due to its very low moisture content (0.43 ± 0.08%) and water activity (0.18 ± 0.07) and its ability to be easily reconstituted in water due to its high solubility index (92.4 ± 1.5%). Therefore, the optimal conditions for the extraction of TIs from defatted Gac seed kernel powder followed by freeze drying gave a high quality powder in terms of its highly specific TIA and physical properties. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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Review

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20 pages, 3856 KiB

Open AccessEditor’s ChoiceReview

Hunting Molecules in Complex Matrices with SPME Arrows: A Review

by Jason S. Herrington, German A. Gómez-Ríos, Colton Myers, Gary Stidsen and David S. Bell

Separations 2020, 7(1), 12; https://doi.org/10.3390/separations7010012 - 15 Feb 2020

Cited by 70 | Viewed by 9183

Abstract

Thirty years since the invention and public disclosure of solid phase microextraction (SPME), the technology continues evolving and inspiring several other green extraction technologies amenable for the collection of small molecules present in complex matrices. In this manuscript, we review the fundamental and [...] Read more.

Thirty years since the invention and public disclosure of solid phase microextraction (SPME), the technology continues evolving and inspiring several other green extraction technologies amenable for the collection of small molecules present in complex matrices. In this manuscript, we review the fundamental and operational aspects of a novel SPME geometry that can be used to “hunt” target molecules in complex matrices: the SPME Arrow. In addition, a series of applications in environmental, food, cannabis and forensic analysis are succinctly covered. Finally, special emphasis is placed on novel interfaces to analytical instrumentation, as well as recent developments in coating materials for the SPME Arrow. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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27 pages, 1471 KiB

Open AccessEditor’s ChoiceReview

Evolution of Environmentally Friendly Strategies for Metal Extraction

by Govind Sharma Shyam Sunder, Sandhya Adhikari, Ahmad Rohanifar, Abiral Poudel and Jon R. Kirchhoff

Separations 2020, 7(1), 4; https://doi.org/10.3390/separations7010004 - 6 Jan 2020

Cited by 55 | Viewed by 11871

Abstract

The demand for the recovery of valuable metals and the need to understand the impact of heavy metals in the environment on human and aquatic life has led to the development of new methods for the extraction, recovery, and analysis of metal ions. [...] Read more.

The demand for the recovery of valuable metals and the need to understand the impact of heavy metals in the environment on human and aquatic life has led to the development of new methods for the extraction, recovery, and analysis of metal ions. With special emphasis on environmentally friendly approaches, efforts have been made to consider strategies that minimize the use of organic solvents, apply micromethodology, limit waste, reduce costs, are safe, and utilize benign or reusable materials. This review discusses recent developments in liquid- and solid-phase extraction techniques. Liquid-based methods include advances in the application of aqueous two- and three-phase systems, liquid membranes, and cloud point extraction. Recent progress in exploiting new sorbent materials for solid-phase extraction (SPE), solid-phase microextraction (SPME), and bulk extractions will also be discussed. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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17 pages, 286 KiB

Open AccessReview

Modern Approaches to Preparation of Body Fluids for Determination of Bioactive Compounds

by Katarzyna Madej and Wojciech Piekoszewski

Separations 2019, 6(4), 53; https://doi.org/10.3390/separations6040053 - 5 Nov 2019

Cited by 10 | Viewed by 4759

Abstract

The current clinical and forensic toxicological analysis of body fluids requires a modern approach to sample preparation characterized by high selectivity and enrichment capability, suitability for micro-samples, simplicity and speed, and the possibility of automation and miniaturization, as well as the use of [...] Read more.

The current clinical and forensic toxicological analysis of body fluids requires a modern approach to sample preparation characterized by high selectivity and enrichment capability, suitability for micro-samples, simplicity and speed, and the possibility of automation and miniaturization, as well as the use of small amounts of reagents, especially toxic solvents. Most of the abovementioned features may be realized using so-called microextraction techniques which cover liquid-phase techniques (e.g., single-drop microextraction, SDME; dispersive liquid–liquid microextraction, DLLME; hollow-fiber liquid-phase microextraction, HF-LPME) and solid-phase extraction techniques (solid-phase microextraction, SPME; microextraction in packed syringes, MEPS; disposable pipette tip extraction, DPX; stir bar sorption extraction, SBSE). Some other extraction methodologies like dispersive solid-phase extraction (d-SPE) or magnetic solid-phase extraction (MSPE) can also be easily miniaturized. This review briefly describes and characterizes the abovementioned extraction methods, and then presents their current applications to the preparation of body fluids analyzed for bioactive compounds in combination with appropriate analytical methods, mainly chromatographic and related techniques. The perspectives of the analytical area we are interested in are also indicated. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

25 pages, 3318 KiB

Open AccessReview

Advancements in Non-Invasive Biological Surface Sampling and Emerging Applications

by Atakan Arda Nalbant and Ezel Boyacı

Separations 2019, 6(4), 52; https://doi.org/10.3390/separations6040052 - 4 Nov 2019

Cited by 13 | Viewed by 5445

Abstract

Biological surfaces such as skin and ocular surface provide a plethora of information about the underlying biological activity of living organisms. However, they pose unique problems arising from their innate complexity, constant exposure of the surface to the surrounding elements, and the general [...] Read more.

Biological surfaces such as skin and ocular surface provide a plethora of information about the underlying biological activity of living organisms. However, they pose unique problems arising from their innate complexity, constant exposure of the surface to the surrounding elements, and the general requirement of any sampling method to be as minimally invasive as possible. Therefore, it is challenging but also rewarding to develop novel analytical tools that are suitable for in vivo and in situ sampling from biological surfaces. In this context, wearable extraction devices including passive samplers, extractive patches, and different microextraction technologies come forward as versatile, low-invasive, fast, and reliable sampling and sample preparation tools that are applicable for in vivo and in situ sampling. This review aims to address recent developments in non-invasive in vivo and in situ sampling methods from biological surfaces that introduce new ways and improve upon existing ones. Directions for the development of future technology and potential areas of applications such as clinical, bioanalytical, and doping analyses will also be discussed. These advancements include various types of passive samplers, hydrogels, and polydimethylsiloxane (PDMS) patches/microarrays, and other wearable extraction devices used mainly in skin sampling, among other novel techniques developed for ocular surface and oral tissue/fluid sampling. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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22 pages, 2331 KiB

Open AccessReview

Development, Optimization and Applications of Thin Film Solid Phase Microextraction (TF-SPME) Devices for Thermal Desorption: A Comprehensive Review

by Ronald V. Emmons, Ramin Tajali and Emanuela Gionfriddo

Separations 2019, 6(3), 39; https://doi.org/10.3390/separations6030039 - 5 Aug 2019

Cited by 61 | Viewed by 11625

Abstract

Through the development of solid phase microextraction (SPME) technologies, thin film solid phase microextraction (TF-SPME) has been repeatedly validated as a novel sampling device well suited for various applications. These applications, encompassing a wide range of sampling methods such as onsite, in vivo [...] Read more.

Through the development of solid phase microextraction (SPME) technologies, thin film solid phase microextraction (TF-SPME) has been repeatedly validated as a novel sampling device well suited for various applications. These applications, encompassing a wide range of sampling methods such as onsite, in vivo and routine analysis, benefit greatly from the convenience and sensitivity TF-SPME offers. TF-SPME, having both an increased extraction phase volume and surface area to volume ratio compared to conventional microextraction techniques, allows high extraction rates and enhanced capacity, making it a convenient and ideal sampling tool for ultra-trace level analysis. This review provides a comprehensive discussion on the development of TF-SPME and the applications it has provided thus far. Emphasis is given on its application to thermal desorption, with method development and optimization for this desorption method discussed in detail. Moreover, a detailed outlook on the current progress of TF-SPME development and its future is also discussed with emphasis on its applications to environmental, food and fragrance analysis. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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18 pages, 2667 KiB

Open AccessReview

Alternative Green Extraction Phases Applied to Microextraction Techniques for Organic Compound Determination

by Eduardo Carasek, Gabrieli Bernardi, Sângela N. do Carmo and Camila M.S. Vieira

Separations 2019, 6(3), 35; https://doi.org/10.3390/separations6030035 - 16 Jul 2019

Cited by 24 | Viewed by 6186

Abstract

The use of green extraction phases has gained much attention in different fields of study, including in sample preparation for the determination of organic compounds by chromatography techniques. Green extraction phases are considered as an alternative to conventional phases due to several advantages [...] Read more.

The use of green extraction phases has gained much attention in different fields of study, including in sample preparation for the determination of organic compounds by chromatography techniques. Green extraction phases are considered as an alternative to conventional phases due to several advantages such as non-toxicity, biodegradability, low cost and ease of preparation. In addition, the use of greener extraction phases reinforces the environmentally-friendly features of microextraction techniques. Thus, this work presents a review about new materials that have been used in extraction phases applied to liquid and sorbent-based microextractions of organic compounds in different matrices. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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21 pages, 3923 KiB

Open AccessEditor’s ChoiceReview

Metal-Organic Frameworks in Green Analytical Chemistry

by Priscilla Rocío-Bautista, Iván Taima-Mancera, Jorge Pasán and Verónica Pino

Separations 2019, 6(3), 33; https://doi.org/10.3390/separations6030033 - 27 Jun 2019

Cited by 107 | Viewed by 13192

Abstract

Metal-organic frameworks (MOFs) are porous hybrid materials composed of metal ions and organic linkers, characterized by their crystallinity and by the highest known surface areas. MOFs structures present accessible cages, tunnels and modifiable pores, together with adequate mechanical and thermal stability. Their outstanding [...] Read more.

Metal-organic frameworks (MOFs) are porous hybrid materials composed of metal ions and organic linkers, characterized by their crystallinity and by the highest known surface areas. MOFs structures present accessible cages, tunnels and modifiable pores, together with adequate mechanical and thermal stability. Their outstanding properties have led to their recognition as revolutionary materials in recent years. Analytical chemistry has also benefited from the potential of MOF applications. MOFs succeed as sorbent materials in extraction and microextraction procedures, as sensors, and as stationary or pseudo-stationary phases in chromatographic systems. To date, around 100 different MOFs form part of those analytical applications. This review intends to give an overview on the use of MOFs in analytical chemistry in recent years (2017–2019) within the framework of green analytical chemistry requirements, with a particular emphasis on possible toxicity issues of neat MOFs and trends to ensure green approaches in their preparation. Full article

(This article belongs to the Special Issue Development of Alternative Green Sample Preparation Techniques)

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