Special Issue "Trends in Microextraction Techniques for Sample Preparation"

A special issue of Separations (ISSN 2297-8739).

Deadline for manuscript submissions: closed (20 September 2017)

Special Issue Editor

Guest Editor
Prof. Dr. Victoria F. Samanidou

Department of Chemistry, Aristotle University of Thessaloniki, Greece
Website | E-Mail
Interests: HPLC analytical methods for the determination of organic substances; GC analytical methods; sample preparation methods: solid phase extraction (SPE), matrix solid phase dispersion (MSPD); inorganic anions analysis by single column ion chromatography; fabric phase sorptive extraction (FPSE)

Special Issue Information

Dear Colleagues,

Micro-extraction techniques in sample preparation are gaining interest among analytical chemists as they comply with green analytical chemistry demands and ensure environmental protection and public safety. Savings in cost and time are considered as valuable benefits by using novel micro-extraction approaches in sample handling. Selectivity, sensitivity and lower detection limits are also included among the performance characteristics required to meet the legislation criteria.

The target of this special issue is to present the state of art in microextraction sample preparation techniques. Modern, simple and efficient methods for preconcentration and separation are described for different analytes isolated from various matrices.

Dr. Victoria F. Samanidou
Guest Editor

Manuscript Submission Information

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Keywords

  • sample preparation
  • preconcentration
  • clean-up
  • microextraction techniques
  • solid phase microextraction
  • stir bar sorptive extraction
  • microextraction by packed syringe
  • fabric phase sorptive extraction
  • matrix solid phase dispersion
  • solid phase extraction
  • hollow fiber liquid phase microextraction

Published Papers (13 papers)

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Research

Jump to: Review

Open AccessArticle Development of an Automated Method for Selected Aromas of Red Wines from Cold-Hardy Grapes Using Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry-Olfactometry
Separations 2017, 4(3), 24; doi:10.3390/separations4030024
Received: 1 June 2017 / Revised: 15 June 2017 / Accepted: 30 June 2017 / Published: 5 July 2017
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Abstract
The aroma profile of red wine is complex and research focusing on aroma compounds and their links to viticultural and enological practices is needed. Current research is limited to wines made from cold-hardy cultivars (interspecific hybrids of vinifera and native N. American grapes).
[...] Read more.
The aroma profile of red wine is complex and research focusing on aroma compounds and their links to viticultural and enological practices is needed. Current research is limited to wines made from cold-hardy cultivars (interspecific hybrids of vinifera and native N. American grapes). The objective of this research was to develop a fully automated solid phase microextraction (SPME) method, using tandem gas chromatography-mass spectrometry (GC-MS)-olfactometry for the simultaneous chemical and sensory analysis of volatile/semi-volatile compounds and aroma in cold-hardy red wines. Specifically, the effects of SPME coating selection, extraction time, extraction temperature, incubation time, sample volume, desorption time, and salt addition were studied. The developed method was used to determine the aroma profiles of seven selected red wines originating from four different cold-hardy grape cultivars. Thirty-six aroma compounds were identified from Maréchal Foch, St. Croix, Frontenac, Vincent, and a Maréchal Foch/Frontenac blend. Among these 36 aroma compounds, isoamyl alcohol, ethyl caproate, benzeneethanol, ethyl decanoate, and ethyl caproate are the top five most abundant aroma compounds. Olfactometry helps to identify compounds not identified by MS. The presented method can be useful for grape growers and wine makers for the screening of aroma compounds in a wide variety of wines and can be used to balance desired wine aroma characteristics. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperArticle A Novel Protocol to Monitor Trace Levels of Selected Polycyclic Aromatic Hydrocarbons in Environmental Water Using Fabric Phase Sorptive Extraction Followed by High Performance Liquid Chromatography-Fluorescence Detection
Separations 2017, 4(2), 22; doi:10.3390/separations4020022
Received: 21 March 2017 / Revised: 9 May 2017 / Accepted: 25 May 2017 / Published: 8 June 2017
PDF Full-text (1499 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Fabric phase sorptive extraction (FPSE) combines the advanced material properties of sol–gel derived microextraction sorbents and the flexibility and permeability of fabric to create a robust, simple and green sample preparation device. It simultaneously improves the extraction sensitivity and the speed of the
[...] Read more.
Fabric phase sorptive extraction (FPSE) combines the advanced material properties of sol–gel derived microextraction sorbents and the flexibility and permeability of fabric to create a robust, simple and green sample preparation device. It simultaneously improves the extraction sensitivity and the speed of the extraction by incorporating high volumes of sponge-like, porous sol–gel hybrid inorganic–organic sorbents into permeable fabric substrates that are capable of extracting target analytes directly from both simple and complex aqueous sample matrices. For the first time, this technique was applied to the trace-level determination of selected polycyclic aromatic hydrocarbons (PAHs) in environmental water samples using a non-polar sol–gel C18 coated FPSE media. Several extraction parameters were optimized to improve the extraction efficiency and to achieve a high detection sensitivity. Validation tests of spiked samples showed good linearity for four selected PAHs (R2 = 0.9983–0.9997) over a wide range of concentrations (0.010–10 ng/mL). Limits of detection (LODs) and quantification (LOQs) were measured at pg/mL levels; 0.1–1 pg/mL and 0.3–3 pg/mL, respectively. Inter- and intra-day precision tests showed variations of 1.1%–4.1% for four selected PAHs. Average absolute recovery values were in the range of 88.1%–90.5% with relative standard deviations below 5%, surpassing the values predicted by the recovery prediction model. Finally, the developed FPSE-HPLC-FLD protocol was applied to analyze 8 environmental water samples. Out of four selected PAHs, fluoranthene (Flu) and phenanthrene (Phen) were the most frequently detected in four samples, at concentrations of 5.6–7.7 ng/mL and 4.1–11 ng/mL, respectively, followed by anthracene (Anth) and pyrene (Pyr) in two samples. The newly developed FPSE-HPLC-FLD protocol is simple, green, fast and economical, with adequate sensitivity for trace levels of four selected PAHs and seems to be promising for routine monitoring of water quality and safety. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessArticle Fabric Phase Sorptive Extraction Explained
Separations 2017, 4(2), 21; doi:10.3390/separations4020021
Received: 17 January 2017 / Revised: 4 May 2017 / Accepted: 12 May 2017 / Published: 2 June 2017
Cited by 1 | PDF Full-text (3322 KB) | HTML Full-text | XML Full-text
Abstract
The theory and working principle of fabric phase sorptive extraction (FPSE) is presented. FPSE innovatively integrates the benefits of sol–gel coating technology and the rich surface chemistry of cellulose/polyester/fiberglass fabrics, resulting in a microextraction device with very high sorbent loading in the form
[...] Read more.
The theory and working principle of fabric phase sorptive extraction (FPSE) is presented. FPSE innovatively integrates the benefits of sol–gel coating technology and the rich surface chemistry of cellulose/polyester/fiberglass fabrics, resulting in a microextraction device with very high sorbent loading in the form of an ultra-thin coating. This porous sorbent coating and the permeable substrate synergistically facilitate fast extraction equilibrium. The flexibility of the FPSE device allows its direct insertion into original, unmodified samples of different origin. Strong chemical bonding between the sol–gel sorbent and the fabric substrate permits the exposure of FPSE devices to any organic solvent for analyte back-extraction/elution. As a representative sorbent, sol–gel poly(ethylene glycol) coating was generated on cellulose substrates. Five (cm2) segments of these coated fabrics were used as the FPSE devices for sample preparation using direct immersion mode. An important class of environmental pollutants—substituted phenols—was used as model compounds to evaluate the extraction performance of FPSE. The high primary contact surface area (PCSA) of the FPSE device and porous structure of the sol–gel coatings resulted in very high sample capacities and incredible extraction sensitivities in a relatively short period of time. Different extraction parameters were evaluated and optimized. The new extraction devices demonstrated part per trillion level detection limits for substitute phenols, a wide range of detection linearity, and good performance reproducibility. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessCommunication Design of a Molecularly Imprinted Stir-Bar for Isolation of Patulin in Apple and LC-MS/MS Detection
Separations 2017, 4(2), 11; doi:10.3390/separations4020011
Received: 31 December 2016 / Revised: 14 March 2017 / Accepted: 20 March 2017 / Published: 24 March 2017
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Abstract
Mycotoxins are a very diverse group of natural products produced as secondary metabolites by fungi. Patulin is produced by mold species normally related to vegetable-based products and fruit, mainly apple. Its ingestion may result in agitation, convulsions, edema, intestinal ulceration, inflammation, vomiting, and
[...] Read more.
Mycotoxins are a very diverse group of natural products produced as secondary metabolites by fungi. Patulin is produced by mold species normally related to vegetable-based products and fruit, mainly apple. Its ingestion may result in agitation, convulsions, edema, intestinal ulceration, inflammation, vomiting, and even immune, neurological or gastrointestinal disorders. For this reason, the European Commission Regulation (EC) 1881/2006 established a maximum content for patulin of 10 ppb in infant fruit juice, 50 ppb for fruit juice for adults and 25 ppb in fruit-derived products. In this work, a rapid and selective method based on magnetic molecularly imprinted stir-bar (MMISB) extraction has been developed for the isolation of patulin, using 2-oxindole as a dummy template. The final extraction protocol consisted of simply pouring in, stirring and pouring out samples and solvents from a beaker with the MMISB acting inside. The magnetic device provided satisfactory recoveries of patulin (60%–70%) in apple samples. The successful MMISB approach has been combined with high performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) to determine patulin. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessArticle A Sensitive LC-MS Method for Anthocyanins and Comparison of Byproducts and Equivalent Wine Content
Separations 2016, 3(2), 18; doi:10.3390/separations3020018
Received: 27 January 2016 / Revised: 29 April 2016 / Accepted: 18 May 2016 / Published: 3 June 2016
Cited by 2 | PDF Full-text (2485 KB) | HTML Full-text | XML Full-text
Abstract
Anthocyanins are a group of phenolic compounds with great importance, not only because they play a crucial role in a wine’s quality, but also due to the fact that they can have beneficial effects on human health. In this work, a method was
[...] Read more.
Anthocyanins are a group of phenolic compounds with great importance, not only because they play a crucial role in a wine’s quality, but also due to the fact that they can have beneficial effects on human health. In this work, a method was developed for the detection and identification of these compounds in solid wastes of the wine-making industry (red grape skins and pomace), using liquid-liquid extraction (LLE) prior to the liquid chromatography-mass spectrometry technique (LC-MS). The complete process was investigated and optimized, starting from the extraction conditions (extraction solution selection, dried matter-to-solvent volume ratio, water bath extraction duration, and necessary consecutive extraction rounds) and continuing to the mobile phase selection. The extraction solution chosen was a methanol/phosphoric acid solution (95/5, v/v), while three rounds of consecutive extraction were necessary in order to extract the maximum amount of anthocyanins from the byproducts. During the LC-MS analysis, acetonitrile was selected as the organic solvent since, compared with methanol, not only did it exhibit increased elution strength, but it also produced significantly narrower peaks. To enable accurate identification of the analytes and optimization of the developed method, kuromanin chloride and myrtillin chloride were used as standards. Furthermore, the wine variety (Syrah) from which the specific byproducts were produced was analyzed for its anthocyanin content, leading to interesting conclusions about which anthocyanins are transferred from grapes to wine during the vinification procedure, and to what extent. The results of this study showed that the total concentration of anthocyanins estimated in wine byproducts exceeded almost 12 times the equivalent concentration in Syrah wine, while the four categories of detected anthocyanins, simple glucosides, acetyl glucosides, cinnamoyl glucosides, and pyroanthocyanins, were present in different ratios among the two samples, ranging from 18.20 to 1, to 5.83 to 1. These results not only confirmed the potential value of these byproducts, but also indicated the complexity of the anthocyanins’ transfer mechanism between a wine and its byproducts. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessArticle Application of Carbon Nanotubes Modified Coatings for the Determination of Amphetamines by In-Tube Solid-Phase Microextraction and Capillary Liquid Chromatography
Separations 2016, 3(1), 7; doi:10.3390/chromatography3010007
Received: 17 December 2015 / Accepted: 6 February 2016 / Published: 1 March 2016
PDF Full-text (2013 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this study, polydimethylsiloxane (PDMS)-coated capillary columns (TRB-5 and TRB-35), both unmodified and functionalized with single-wall carbon nanotubes (SWCNTs) or multiwall carbon nanotubes (MWCNTs), have been tested and compared for the extraction of amphetamine (AMP), methamphetamine (MET) and ephedrine (EPE) by in-tube solid-phase
[...] Read more.
In this study, polydimethylsiloxane (PDMS)-coated capillary columns (TRB-5 and TRB-35), both unmodified and functionalized with single-wall carbon nanotubes (SWCNTs) or multiwall carbon nanotubes (MWCNTs), have been tested and compared for the extraction of amphetamine (AMP), methamphetamine (MET) and ephedrine (EPE) by in-tube solid-phase microextraction (IT-SPME). Prior to their extraction, the analytes were derivatized with the fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC). For separation and detection capillary chromatography with fluorimetric detection has been used. The presence of carbon nanotubes in the extractive coatings enhanced the extraction efficiencies and also significantly improved the chromatographic profiles, thus resulting in a reliable option for the analysis of these drugs. As an example of application, a new method is proposed for the analysis of the tested amphetamines in oral fluid using a TRB-35 capillary column functionalized with MWCNTs. The proposed conditions provided suitable selectivity and reproducibility (CV ≤ 6%, n = 3) at low µg/mL levels, and limits of detection of 0.5–0.8 µg/mL. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Review

Jump to: Research

Open AccessFeature PaperReview Recent Trends in Microextraction Techniques Employed in Analytical and Bioanalytical Sample Preparation
Separations 2017, 4(4), 36; doi:10.3390/separations4040036
Received: 16 October 2017 / Revised: 24 November 2017 / Accepted: 27 November 2017 / Published: 1 December 2017
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Abstract
Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device;
[...] Read more.
Sample preparation has been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been made in recent years to simplify the overall sample preparation process. Major focusses of these efforts have included miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these improved attributes are congruent with the Green Analytical Chemistry (GAC) principles. Classical sample preparation techniques such as solid phase extraction (SPE) and liquid-liquid extraction (LLE) are being rapidly replaced with emerging miniaturized and environmentally friendly techniques such as Solid Phase Micro Extraction (SPME), Stir bar Sorptive Extraction (SBSE), Micro Extraction by Packed Sorbent (MEPS), Fabric Phase Sorptive Extraction (FPSE), and Dispersive Liquid-Liquid Micro Extraction (DLLME). In addition to the development of many new generic extraction sorbents in recent years, a large number of molecularly imprinted polymers (MIPs) created using different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high-performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity of modern chromatographic analyses to a new level. Combining magnetic nanoparticles with many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volumes of matrix interferents. The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drug monitoring to the environmental field; from foods to phyto-pharmaceutical applications. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperReview Trends in Microextraction-Based Methods for the Determination of Sulfonamides in Milk
Separations 2017, 4(3), 23; doi:10.3390/separations4030023
Received: 1 May 2017 / Revised: 6 June 2017 / Accepted: 12 June 2017 / Published: 23 June 2017
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Abstract
Sulfonamides (SAs) represent a significant category of pharmaceutical compounds due to their effective antimicrobial characteristics. SAs were the first antibiotics to be used in clinical medicine to treat a majority of diseases, since the 1900s. In the dairy farming industry, sulfa drugs are
[...] Read more.
Sulfonamides (SAs) represent a significant category of pharmaceutical compounds due to their effective antimicrobial characteristics. SAs were the first antibiotics to be used in clinical medicine to treat a majority of diseases, since the 1900s. In the dairy farming industry, sulfa drugs are administered to prevent infection, in several countries. This increases the possibility that residual drugs could pass through milk consumption even at low levels. These traces of SAs will be detected and quantified in milk. Therefore, microextraction techniques must be developed to quantify antibiotic residues, taking into consideration the terms of Green Analytical Chemistry as well. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperReview Fabric Sol–gel Phase Sorptive Extraction Technique: A Review
Separations 2017, 4(2), 20; doi:10.3390/separations4020020
Received: 5 January 2017 / Revised: 15 May 2017 / Accepted: 18 May 2017 / Published: 24 May 2017
Cited by 2 | PDF Full-text (1823 KB) | HTML Full-text | XML Full-text
Abstract
Since the introduction in 2014 of fabric phase sorptive extraction (FPSE) as a sample preparation technique, it has attracted the attention of many scientists working in the field of separation science. This novel sorbent extraction technique has successfully utilized the benefits of sol–gel
[...] Read more.
Since the introduction in 2014 of fabric phase sorptive extraction (FPSE) as a sample preparation technique, it has attracted the attention of many scientists working in the field of separation science. This novel sorbent extraction technique has successfully utilized the benefits of sol–gel derived hybrid sorbents and a plethora of fabric substrates, resulting in a highly efficient, sensitive and green sample pretreatment methodology. The proposed procedure is an easy and efficient pathway to extract target analytes from different matrices providing inherent advantages such as high sample loading capacity and short pretreatment time. The present review mainly focuses on the background and sol–gel chemistry for the preparation of new fabric sorbents as well as on the applications of FPSE for extracting target analytes, from the time that it was first introduced. New modes of FPSE including stir FPSE, stir-bar FPSE, dynamic FPSE, and automated on-line FPSE are also highlighted and commented upon in detail. FPSE has been effectively applied for the determination of various organic and inorganic analytes in different types of environmental and biological samples in high throughput analytical, environmental, and toxicological laboratories. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperReview Recent Advances in Microextraction Techniques of Antipsychotics in Biological Fluids Prior to Liquid Chromatography Analysis
Separations 2017, 4(2), 18; doi:10.3390/separations4020018
Received: 30 January 2017 / Revised: 19 April 2017 / Accepted: 5 May 2017 / Published: 12 May 2017
PDF Full-text (840 KB) | HTML Full-text | XML Full-text
Abstract
Antipsychotic drugs are a class of psychiatric medication worldwide used to treat psychotic symptoms principally in bipolar disorder, schizophrenia and other psycho-organic disorders. The traditional sample preparation techniques such as liquid-liquid extraction (LLE) or solid phase extraction (SPE), which were widely used, tend
[...] Read more.
Antipsychotic drugs are a class of psychiatric medication worldwide used to treat psychotic symptoms principally in bipolar disorder, schizophrenia and other psycho-organic disorders. The traditional sample preparation techniques such as liquid-liquid extraction (LLE) or solid phase extraction (SPE), which were widely used, tend to have many drawbacks because they include complicated, time-consuming steps and they require large sample size as well large amounts of organic solvent. Therefore, due to the modern analytical requirements, such as miniaturization, automation and reduction of solvent volume and time, many microextraction procedures have been developed. In this review we aim to present an overview of those techniques which are used prior to liquid chromatography analyses both for forensic toxicology in different biological matrices as well as for therapeutic drug monitoring. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessReview Carbon-Based Nanomaterials Functionalized with Ionic Liquids for Microextraction in Sample Preparation
Separations 2017, 4(2), 14; doi:10.3390/separations4020014
Received: 9 February 2017 / Revised: 30 March 2017 / Accepted: 4 April 2017 / Published: 10 April 2017
Cited by 1 | PDF Full-text (1358 KB) | HTML Full-text | XML Full-text
Abstract
A large number of carbon-based nanomaterials has been investigated as sorbents in sample preparation, including fullerenes, carbon nanotubes, nanofibers, nanohorns and graphene, as well as their functionalized forms. Taking into account their properties, carbon-based nanomaterials have found a wide range of applications in
[...] Read more.
A large number of carbon-based nanomaterials has been investigated as sorbents in sample preparation, including fullerenes, carbon nanotubes, nanofibers, nanohorns and graphene, as well as their functionalized forms. Taking into account their properties, carbon-based nanomaterials have found a wide range of applications in different sample preparation techniques. Ionic liquids, as an alternative to environmentally-harmful ordinary organic solvents, have attracted extensive attention and gained popularity in analytical chemistry covering different fields like chromatography, electrochemistry and (micro)extraction. Some of the properties of ionic liquids, including polarity, hydrophobicity and viscosity, can be tuned by the proper selection of the building cations and anions. Their tunable nature allows the synthesis of tailor-made solvents for different applications. This review provides a snapshot of the most important features and applications of different carbon-based nanomaterials functionalized with ionic liquids for sample preparation. Emphasis is placed on the description of the different works that have provided interesting results for the use of graphene and carbon nanotubes, in this analytical field. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperReview Recent Advances in Extraction and Stirring Integrated Techniques
Separations 2017, 4(1), 6; doi:10.3390/separations4010006
Received: 31 January 2017 / Revised: 6 March 2017 / Accepted: 7 March 2017 / Published: 15 March 2017
Cited by 4 | PDF Full-text (5257 KB) | HTML Full-text | XML Full-text
Abstract
The extraction yield of a microextraction technique depends on thermodynamic and kinetics factors. Both of these factors have been the focus of intensive research in the last few years. The extraction yield can be increased by synthesizing and using novel materials with favorable
[...] Read more.
The extraction yield of a microextraction technique depends on thermodynamic and kinetics factors. Both of these factors have been the focus of intensive research in the last few years. The extraction yield can be increased by synthesizing and using novel materials with favorable distribution constants (one of the thermodynamic factors) for target analytes. The extraction yield can also be increased by improving kinetic factors, for example, by developing new extraction modes. Microextraction techniques are usually non-exhaustive processes that work under the kinetic range. In such conditions, the improvement of the extraction kinetics necessarily improves the performance. Since the extraction yield and efficiency is related to how fast the analytes diffuse in samples, it is crucial to stir the sample during extraction. The stirring can be done with an external element or can be integrated with the extraction element in the same device. This article reviews the main recent advances in the so-called extraction/stirring integrated techniques with emphasis on their potential and promising approaches rather than in their applications. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)
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Open AccessFeature PaperReview On the Extraction of Antibiotics from Shrimps Prior to Chromatographic Analysis
Separations 2016, 3(1), 8; doi:10.3390/chromatography3010008
Received: 2 February 2016 / Revised: 18 February 2016 / Accepted: 26 February 2016 / Published: 4 March 2016
Cited by 2 | PDF Full-text (1999 KB) | HTML Full-text | XML Full-text
Abstract
The widespread use of antibiotics in veterinary practice and aquaculture has led to the increase of antimicrobial resistance in food-borne pathogens that may be transferred to humans. Global concern is reflected in the regulations from different agencies that have set maximum permitted residue
[...] Read more.
The widespread use of antibiotics in veterinary practice and aquaculture has led to the increase of antimicrobial resistance in food-borne pathogens that may be transferred to humans. Global concern is reflected in the regulations from different agencies that have set maximum permitted residue limits on antibiotics in different food matrices of animal origin. Sensitive and selective methods are required to monitor residue levels in aquaculture species for routine regulatory analysis. Since sample preparation is the most important step, several extraction methods have been developed. In this review, we aim to summarize the trends in extraction of several antibiotics classes from shrimps and give a comparison of performance characteristics in the different approaches. Full article
(This article belongs to the Special Issue Trends in Microextraction Techniques for Sample Preparation)

Planned Papers

The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.

Title: Microextraction techniques used in the sample preparation for determining sulfonamides in milk.
Authors: Maria Kechagia and Victoria Samanidou*
Affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Greece. 54124 Thessaloniki Greece.
Abstract: Sulfonamides (SAs) represent a significant category of pharmaceutical compounds due to the effective antimicrobial characteristics. The sulfonamides were the first antibiotics to be used in the clinical medicine to treat a majority of diseases, continuously since the 1900s. In the dairy farming industry, sulfa drugs are administered to prevent infection. This increases the possibility that through consumption of milk, rags at low levels could pass to the consumer. These traces of the sulfonamides to the milk will be detected and quantified. Therefore microextraction techniques must be developed in terms of Green Analytical Chemistry.

Title: Fabric phase sorptive extraction: A new sample preparation tool, background and applications. A review
Authors: Viktoria Kazantzi and Aristidis Anthemidis
Affiliation: Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki, Greece. 54124 Thessaloniki Greece.
Abstract: Definitely, sample pretreatment procedures, still remain the bottleneck of an analytical method. Recently, Kabir and Furton, introduced a novel sample preparation technique known as fabric phase sorptive extraction (FPSE), in order to overcome the major shortcomings of the most commonly used sample preparation techniques, such as poor extraction performance for highly polar analytes as well as low sorbent loading. Up-to-date, FPSE has been used in batch mode, for the determination of various organic compounds in different types of samples. In addition, an automation of this technique (Fabric Disk Sorptive Extraction, FDSE) presented, in order to overcome drawbacks of the batch-mode extraction procedure. This review provides a summary of the most important information regarding the basic principles as well as the applications of the FPSE / FDSE technique in diverse fields of analytical chemistry. Furthermore, sol-gel sorbent materials used in FPSE are also presented along with the processes of each substrate and sol-gel coating.

Title: Carbon-based nanomaterials functionalized with ionic liquids for microextraction in sample preparation
Authors: Theodoros Chatzimitakos and Constantine Stalikas
Affiliation: Department of Chemistry, University of Ioannina, Ioannina 451 10, Greece
Abstract: A large number of carbon-based nanomaterials have been investigated as sorbents in sample preparation, including fullerenes, carbon nanotubes, nanofibers, nanohorns and graphene as well as their functionalized forms. Taking into account their properties, carbon-based nanomaterials have found a wide range of applications in different sample preparation techniques. Ionic liquids, as an alternative to environmentally harmful ordinary organic solvents have attracted extensive attention and gained popularity in analytical chemistry covering different fields like chromatography, electrochemistry and (micro)extraction. Some of the properties of ionic liquids, including polarity, hydrophobicity and viscosity can be tuned by the proper selection of the building cations and anions. Their tunable nature allows the synthesis of tailor-made solvents for different applications. This review provides a snapshot of the applications of different carbon-based nanomaterials functionalized with ionic liquids for sample preparation. Particular attention has been paid to graphene and carbon nanotubes.

Type of the paper: review
Tentative Title: Analytical prospects of using microextraction approaches for the analysis of polar compounds in environmental matrices
Authors: João T.V. Matos, Regina M.B.O. Duarte, Armando C. Duarte*
Affiliations: Department of Chemistry & CESAM, University of Aveiro, 3810-193 Aveiro, Portugal
Abstract: The miniaturization and improvement of sample preparation has drawn much attention in many fields of analytical chemistry. The feasibility of microextraction approaches for the pre-concentration of analytes with different polarity in environmental samples has been demonstrated. However, the application of these techniques to polar compounds could still be a challenge due to the characteristics of the extraction material (in sorbent-based methods) and/or solvent (in liquid-based methods). This review aims to provide a critical assessment on the applications and challenges of using microextraction techniques to isolate and pre-concentrate traces of organic polar compounds from different environmental matrices.

Title: Recent advances in microextraction techniques of antipsychotics in biological fluids prior to liquid chromatography analysis
Authors: Natalia Manousi 1,2, Georg Raber 1* and Ioannis Papadoyannis2
Affiliation: 1 Institute of Chemistry, University of Graz.
2 Laboratory of Analytical Chemistry, Department of Chemistry, Aristotle University of Thessaloniki.
E-mail: georg.raber@uni-graz.at
Abstract: Antipsychotic drugs are a class of psychiatric medication worldwide used to treat psychotic symptoms principally in schizophrenia, bipolar disorder and psycho-organic disorders. The conventional sample preparation techniques such as liquid-liquid extraction (LLE) and solid phase extraction (SPE), which are widely used, tend to have many drawbacks because they include complicated, time-consuming steps and they require large amounts of sample and organic solvent. Therefore, due to the modern trend of miniaturization, automatization and reduction of solvent consumption and time, many microextraction procedures were developed. In this review we aim to present an overview of those techniques which are used prior to liquid chromatography analysis both for forensic toxicology in different biological matrices as well as for therapeutic drug monitoring.

Title: Recent trends in microextraction techniques employed in analytical and bioanalytical sample preparation
Author: Abuzar Kabir1, Marcello Locatelli2,3,*, Halil Ibrahim Ulusoy
Affiliation:
1 International Forensic Research Institute, Department of Chemistry and Biochemistry, Florida International University, Miami, FL, USA
2 Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, Chieti (CH), Italy
3 Interuniversity Consortium of Structural and Systems Biology INBB, Rome, Italy
4 Department of Analytical Chemistry, Faculty of Pharmacy, Cumhuriyet University, Sivas, Turkey
Correspondance: Marcello Locatelli, Ph.D., Department of Pharmacy, University “G. d’Annunzio” of Chieti-Pescara, Via dei Vestini 31, build B, level 2, 66100 Chieti (CH), Italy; E-mail:
Abstract: After being neglected for decades, sample preparation has finally been recognized as a major step in the chemical analysis workflow. As such, substantial efforts have been invested in recent years to simplify the overall sample preparation process. Major focusses of these efforts include, miniaturization of the extraction device; minimizing/eliminating toxic and hazardous organic solvent consumption; eliminating sample pre-treatment and post-treatment steps; reducing the sample volume requirement; reducing extraction equilibrium time, maximizing extraction efficiency etc. All these attributes corroborate with the Green Analytical Chemistry principles. Classical sample preparation techniques such as solid phase extraction (SPE) and liquid-liquid extraction (LLE) are being rapidly replaced with emerging miniaturized and environment friendly techniques including Micro Extraction by Packed Sorbent (MEPS), Fabric Phase Sorptive Extraction (FPSE), Dispersive Liquid-Liquid Micro Extraction (DLLME). In addition to the development of many new generic extraction sorbents, a large number of molecularly imprinted polymers (MIPs) based on different template molecules have also enriched the large cache of microextraction sorbents. Application of nanoparticles as high performance extraction sorbents has undoubtedly elevated the extraction efficiency and method sensitivity to new level. Connecting magnetic nanoparticles to many microextraction sorbents has opened up new possibilities to extract target analytes from sample matrices containing high volume of matrix interferents.
The aim of the current review is to critically audit the progress of microextraction techniques in recent years, which has indisputably transformed the analytical chemistry practices, from biological and therapeutic drugs monitoring to environmental field, from foods to phyto-pharmaceuticals applications.
Keywords: MEPS, FPSE, DLLME, magnetic solid phase extraction (MSPE); extraction procedures

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