One of the most cited limitations of capillary (and microchip) electrophoresis is the poor sensitivity. This review continues to update this series of biannual reviews, first published in ...Electrophoresis in 2007, on developments in the field of on‐line/in‐line concentration methods, covering the period July 2012–July 2014. It includes developments in the field of stacking, covering all methods from field‐amplified sample stacking and large‐volume sample stacking, through to ITP, dynamic pH junction, and sweeping. Attention is also given to on‐line or in‐line extraction methods that have been used for electrophoresis.
Although containing significant levels of phenolic compounds (PCs), leaves biomass coming from either forest, agriculture, or the processing industry are considered as waste, which upon disposal, ...brings in environmental issues. As the demand for PCs in functional food, pharmaceutical, nutraceutical and cosmetic sector is escalating day by day, recovering PCs from leaves biomass would solve both the waste disposal problem while ensuring a valuable "societal health" ingredient thus highly contributing to a sustainable food chain from both economic and environmental perspectives. In our search for environmentally benign, efficient, and cost-cutting techniques for the extraction of PCs, green extraction (GE) is presenting itself as the best option in modern industrial processing. This current review aims to highlight the recent progress, constraints, legislative framework, and future directions in GE and characterization of PCs from leaves, concentrating particularly on five plant species (tea, moringa, stevia, sea buckthorn, and pistacia) based on the screened journals that precisely showed improvements in extraction efficiency along with maintaining extract quality. This overview will serve researchers and relevant industries engaged in the development of suitable techniques for the extraction of PCs with increasing yield.
•Magnetic particles in solid phase extraction for metal determination.•Synthesis, characterization, classification and applications of MPs.•On-line implementation in SIA, LOV and microfluidic ...systems.•Critical evaluation of on-line column packing in MSPE.
The use of magnetic materials in solid phase extraction has received considerable attention in recent years taking into account many advantages arising from the inherent characteristics of magnetic particles. Magnetic solid phase extraction (MSPE) methodology overcomes problems such as column packing and phase separation, which can be easily performed by applying an external magnetic field. The use of magnetic particles in automatic systems is growing over the last few years making the on-line operation of MSPE a promising technique in the frame of green chemistry. This article aims to provide all recent progress in the research of novel magnetic materials as sorbents for metal preconcentration and determination coupled with different detection systems as well as their implementation in sequential injection and microfluidic systems. In addition, a description of preparation, characterization as well as applications of various types of magnetic materials, either with organic or inorganic coating of the magnetic core, is presented. Concluding remarks and future trends are also commented.
Growing attention to environmental protection leads food industries to adopt a model of “circular economy” applying safe and sustainable technologies to recover, recycle and valorize by-products. ...Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized.
The efficiency of conventional solid-liquid extraction methods to extract C-Phycocyanin (C-PC) from given biomass is very low because of the resistance offered by the cell membrane for its ...disruption. The present work aims at developing an efficient protocol for primary extraction of C-PC from dry biomass of Arthrospira platensis. Surfactant (Triton X-100, Tween 20 and Tween 80) and enzyme-assisted (lysozyme) methods were attempted. Process parameters such as incubation time, solid-liquid ratio and surfactant/enzyme concentration were standardized for pre-soaked (120 min) biomass. Enzyme-assisted extraction (at 0.6% enzyme concentration and 16 h incubation) resulted in the highest C-Phycocyanin purity of 1.19 with a satisfactory yield of 82.07 mg/g dry biomass (68.96% extraction efficiency). Among surfactants, Tween 80 (at 0.6% Tween 80 concentration and 50 min incubation) resulted in the highest yield of 71.94 mg/g dry biomass (71.94% extraction efficiency) with a purity of 0.8. Ultrasonication was carried out in combination with these two methods (one at a time) at already standardized conditions to explore the synergy between them. Compared all the methods studied, ultrasonication with enzyme-assisted extraction resulted in the highest C-PC yield of 92.73 mg/g dry biomass (77.92% extraction efficiency) with a purity of 1.09 and was inferred as the best method.
•Enzyme-assisted method was used for extraction of C-Phycocyanin.•Surfactant-assisted method was also used.•These methods were applied in combination with Ultrasonication to achieve synergy.•Combining processes increased C-Phycocyanin yield compared to individual methods.•Yield of 82% with 1.09 purity was achieved by Ultrasound-assisted enzymatic method.
•Salting-out assisted liquid–liquid extraction in acetonitrile–water mixtures is discussed.•The liquid phase separation and the analytes’ fraction extracted were evaluated.•Carbonate and sulfate ...salts produced higher phase ratios and fractions extracted.•Studies on beer samples corroborated the results obtained in model solutions.
The use of the salting-out effect in analytical chemistry is very diverse and can be applied to increase the volatility of the analytes in headspace extractions, to cause the precipitation of proteins in biological samples or to improve the recoveries in liquid–liquid extractions. In the latter, the salting-out process can be used to create a phase separation between water-miscible organic solvents and water. Salting-out assisted liquid–liquid extraction (SALLE) is an advantageous sample preparation technique aiming HPLC-UV analysis when developing analytical methodologies. In fact, some new extraction methodologies like QuEChERS include the SALLE concept. This manuscript discusses another point of view over SALLE with particular emphasis over acetonitrile–water mixtures for HPLC-UV analysis; the influence of the salting-out agents, their concentration and the water–acetonitrile volume ratios were the studied parameters. α-dicarbonyl compounds and beer were used as test analytes and test samples, respectively. The influence of the studied parameters was characterized by the obtained phase separation volume ratio and the fraction of α-dicarbonyls extracted to the acetonitrile phase. Results allowed the distribution of salts within three groups according to the phase separation and their extractability: (1) chlorides and acetates, (2) carbonates and sulfates and (3) magnesium sulfate; of all tested salts, sodium chloride had the highest influence on the α-dicarbonyls fraction extracted.
Anthocyanins have gathered the attention of the scientific community mostly due to their vast range of possible applications. They have been the center point of the research in many different fields, ...among which is food development, where their innate coloring, antioxidant capacity, and biological potential open interesting venues to the development of new food additives and functional foodstuffs. As the range of application grows, so does the necessity to obtain these compounds, and since they are naturally occurring, the most common way to obtain anthocyanins is to extract them from different plant sources, such as fruits and flowers. Several efforts have been made to develop methods that allow for better extraction yields and higher purification rates therefore this review aims to compile the information regarding extraction and purification procedures in a comprehensive manner.
Following our previous reviews, this manuscript presents an updated perspective on the use of compressed fluids, mainly under sub- and supercritical conditions, for the extraction of bioactive ...components from natural matrices covering the period from 2015 to present. These extraction technologies might have an important role in the development of sustainable and efficient extraction processes to cope with the high demand of natural bioactive compounds. Moreover, more complex approaches based on process integration, intensification and the development of sequential valorization chains are being increasingly developed. Most recent and interesting applications grouped according to the type of natural material used (plants, seaweeds, microalgae and food-related by-products) are described and critically commented. Furthermore, we discuss the potential future outlooks related to this field in agreement with our own experience.
•Recent developments of compressed fluid-based extraction are discussed.•PLE and SFE are widely employed to obtain bioactive components from natural sources.•Biorefinery and integrated approaches for plants, by-products and microalgae are described and discussed.•The use of green solvents for the extraction of bioactives is deeply discussed.
Marine microalgae and seaweeds (microalgae) represent a sustainable source of various bioactive natural carotenoids, including β-carotene, lutein, astaxanthin, zeaxanthin, violaxanthin and ...fucoxanthin. Recently, the large-scale production of carotenoids from algal sources has gained significant interest with respect to commercial and industrial applications for health, nutrition, and cosmetic applications. Although conventional processing technologies, based on solvent extraction, offer a simple approach to isolating carotenoids, they suffer several, inherent limitations, including low efficiency (extraction yield), selectivity (purity), high solvent consumption, and long treatment times, which have led to advancements in the search for innovative extraction technologies. This comprehensive review summarizes the recent trends in the extraction of carotenoids from microalgae and seaweeds through the assistance of different innovative techniques, such as pulsed electric fields, liquid pressurization, supercritical fluids, subcritical fluids, microwaves, ultrasounds, and high-pressure homogenization. In particular, the review critically analyzes technologies, characteristics, advantages, and shortcomings of the different innovative processes, highlighting the differences in terms of yield, selectivity, and economic and environmental sustainability.
In spite of the huge development of analytical instrumentation during last two decades, sample preparation is still nowadays considered the bottleneck of the whole analytical process. In this regard, ...efforts have been conducted towards the improvement of the selectivity during extraction and/or subsequent clean-up of sample extracts. Molecularly imprinted polymers (MIPs) are stable polymers with molecular recognition abilities, provided by the presence of a template during their synthesis and thus are excellent materials to provide selectivity to sample preparation. In the present review, the use of MIPs in solid-phase extraction and solid-phase microextraction as well as its recent incorporation to other extraction techniques such as matrix-solid phase dispersion and stir bar sorptive extraction, among others, is described. The advantages and drawbacks of each methodology as well as the future expected trends are discussed.
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