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Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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advances in solid phase Microextraction and perspective on future directions
Analytical Chemistry, 2018Co-Authors: Nathaly Reyesgarces, Emanuela Gionfriddo, German Augusto Gomezrios, Md Nazmul Alam, Ezel Boyaci, Barbara Bojko, Varoon Singh, Jonathan J Grandy, Janusz PawliszynAbstract:Solid phase Microextraction (SPME) is a versatile, non-exhaustive sample preparation tool that has been demonstrated to be well-suited for facile and effective analysis of a broad range of compounds in a plethora of studies. A growing number of reports describing diverse SPME workflows for novel investigations in a variety of fields, such as flavor and fragrance investigations, environmental studies, and diverse bioanalytical applications, among others, corroborate the applicability of this Microextraction tool in the analytical sciences
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a critical review of solid phase Microextraction for analysis of water samples
Trends in Analytical Chemistry, 2016Co-Authors: Hamed Pirimoghadam, Fardin Ahmadi, Janusz PawliszynAbstract:Abstract The review summarizes applications of solid phase Microextraction (SPME) for water sample analysis. Official methods and standards of SPME in water research and inter-laboratory validation are discussed. A comparison of SPME with current EPA-approved methods from several analytical aspects is presented. The review also provides some perspectives of the recent development of SPME on sampling water using artificial river systems, in the passive sampling and on-site sampling. Recently developed configuration of SPME such as thin film Microextraction and high-throughput applications ( e.g. when used in a 96-blade configuration) are shown.
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thin film Microextraction offers another geometry for solid phase Microextraction
Trends in Analytical Chemistry, 2012Co-Authors: Ruifen Jiang, Janusz PawliszynAbstract:Abstract As a new geometry for solid-phase Microextraction, thin-film Microextraction (TFME) has become an attractive sample-preparation technique. The high surface area-to-volume ratio together with the increase of extraction-phase volume enhanced the sensitivity of this technique without sacrificing the sampling time compared to other Microextraction approaches. Comprehensive research has demonstrated the good agreement of the experimental data with the fundamental principle of this technique. In this review, we summarize the theory of the sampling process, the reported calibration methods and diverse TFME formats, different structures of the extraction phase and related preparation methods. Furthermore, we discuss approaches to TFME desorption, coupling with different analytical instruments and the main applications of this technique.
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Microextraction of drugs
Journal of Chromatography A, 2000Co-Authors: Heather Lord, Janusz PawliszynAbstract:This review will attempt to provide an overview as well as a theoretical and practical understanding of the use of Microextraction technologies for drug analysis. The majority of the published reports to date focus on the use of fibre solid-phase Microextraction and so the review is significantly focused on this technology. Other areas of Microextraction such as single drop and solvent film Microextraction are also described. Where there are insufficient examples in the literature to illustrate important concepts, examples of non-drug analyses are presented. The review is intended for readers new to the field of Microextraction or its use in drug extraction, but also provides an overview of the most recent advances in the field which may be of interest to more experienced users. Particular emphasis is placed on the effect various sample matrices have on extraction characteristics.
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automated in tube solid phase Microextraction coupled to high performance liquid chromatography
Analytical Chemistry, 1997Co-Authors: Ralf Eisert And, Janusz PawliszynAbstract:Recently, solid-phase Microextraction (SPME) was successfully coupled to high-performance liquid chromatography. However, the efficiency of this analytical method, in terms of manpower, still suffers from its manual operation technique. Furthermore, the selectivity obtained for the analysis of very polar compounds is still poor because of a limited selection of commercially available fiber coatings that can withstand the aggressive HPLC conditions (solvents). This paper describes the first approach to developing an automated SPME-HPLC system. A mixture of polar thermally labile analytes, phenylurea pesticides, was selected for Microextraction directly from an aqueous sample. A piece of a ordinary capillary GC column with its coating (Omegawax 250) was used for the absorption of analytes from the aqueous sample (in-tube solid-phase Microextraction). A needle hosts the capillary when it is pierced through the septum of the vial containing the spiked aqueous sample. The aqueous samples were stored in 2 mL vi...
Carlos Bendicho - One of the best experts on this subject based on the ideXlab platform.
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speciation of mercury by ionic liquid based single drop Microextraction combined with high performance liquid chromatography photodiode array detection
Talanta, 2009Co-Authors: Francisco Penapereira, Isela Lavilla, Carlos Bendicho, Lorena Vidal, Antonio CanalsAbstract:Abstract Room temperature ionic liquids can be considered as environmentally benign solvents with unique physicochemical properties. Ionic liquids can be used as extractant phases in SDME, being compatible with chromatographic systems. A single-drop Microextraction method was developed for separation and preconcentration of mercury species (MeHg + , EtHg + , PhHg + and Hg 2+ ), which relies on the formation of the corresponding dithizonates and Microextraction of these neutral chelates onto a microdrop of an ionic liquid. Afterwards, the separation and determination were carried out by high-performance liquid chromatography with a photodiode array detector. Variables affecting the formation and extraction of mercury dithizonates were optimized. The optimum conditions found were: Microextraction time, 20 min; stirring rate, 900 rpm; pH, 11; ionic liquid type, 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 MIM][PF 6 ]); drop volume, 4 μL; and no sodium chloride addition. Limits of detection were between 1.0 and 22.8 μg L −1 for the four species of mercury, while the repeatability of the method, expressed as relative standard deviation, was between 3.7 and 11.6% ( n = 8). The method was finally applied to the determination of mercury species in different water samples.
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miniaturized preconcentration methods based on liquid liquid extraction and their application in inorganic ultratrace analysis and speciation a review
Spectrochimica Acta Part B: Atomic Spectroscopy, 2009Co-Authors: Francisco Penapereira, Isela Lavilla, Carlos BendichoAbstract:Abstract Liquid–liquid extraction (LLE) is widely used as a pre-treatment technique for separation and preconcentration of both organic and inorganic analytes from aqueous samples. Nevertheless, it has several drawbacks, such as emulsion formation or the use of large volumes of solvents, which makes LLE expensive and labour intensive. Therefore, miniaturization of conventional liquid–liquid extraction is needed. The search for alternatives to the conventional LLE using negligible volumes of extractant and the minimum number of steps has driven the development of three new miniaturized methodologies, i.e. single-drop Microextraction (SDME), hollow fibre liquid-phase Microextraction (HF-LPME) and dispersive liquid–liquid Microextraction (DLLME). The aim of this paper is to provide an overview of these novel preconcentration approaches and their potential use in analytical labs involved in inorganic (ultra)trace analysis and speciation. Relevant applications to the determination of metal ions, metalloids, organometals and non-metals are included.
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immersed single drop Microextraction interfaced with sequential injection analysis for determination of cr vi in natural waters by electrothermal atomic absorption spectrometry
Spectrochimica Acta Part B: Atomic Spectroscopy, 2008Co-Authors: Francisco Pena, Isela Lavilla, Carlos BendichoAbstract:Abstract Single-drop Microextraction (SDME) and sequential injection analysis have been hyphenated for ultratrace metal determination by Electrothermal-Atomic Absorption Spectrometry (ETAAS). The novel method was targeted on extraction of the Cr(VI)-APDC chelate and encompasses the potential of SDME as a miniaturized and virtually solvent-free preconcentration technique, the ability of sequential injection analysis to handle samples and the versatility of furnace autosamplers for introducing microliter samples in ETAAS. The variables influencing the Microextraction of Cr(VI) onto an organic solvent drop, i.e., type of organic solvent, Microextraction time, stirring rate of the sample solution, drop volume, immersion depth of the drop, salting-out effect, temperature of the sample, concentration of the complexing agent and pH of the sample solution were fully investigated. For a 5 and 20 min Microextraction time, the preconcentration factors were 20 and 70, respectively. The detection limit was 0.02 µg/L of Cr(VI) and the repeatability expressed as relative standard deviation was 7%. The SDME-SIA-ETAAS technique was validated against BCR CRM 544 (lyophilized solution) and applied to ultrasensitive determination of Cr(VI) in natural waters.
Hian Kee Lee - One of the best experts on this subject based on the ideXlab platform.
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determination of ultraviolet filters in water samples by vortex assisted dispersive liquid liquid Microextraction followed by gas chromatography mass spectrometry
Journal of Chromatography A, 2012Co-Authors: Yufeng Zhang, Hian Kee LeeAbstract:Abstract For the first time, a simple solvent Microextraction method termed vortex-assisted liquid–liquid Microextraction (VADLLME) coupled with gas chromatography–mass spectrometry (GC–MS) has been developed and used for the analysis of six benzophenone ultraviolet (UV) filters (i.e. benzhydrol, 2,4-dihydroxybenzophenone, benzophenone, 2-hydroxy-4-methoxybenzophenone, ethylhexyl salicylate and homosalate) in water samples. The most favorable extraction variables in the VADLLME process were determined. In the extraction procedure, 40 μL of tetrachloroethene as extraction solvent were directly injected into a 15-mL centrifuge tube containing 10 mL of aqueous sample, adjusted to pH 4 for VADLLME. After VADLLME, the extract was evaporated under a gentle nitrogen gas stream and then reconstituted with N , O -bis-(trimethylsilyl)trifluoroacetamide (BSTFA), thus allowing the target analytes to be converted into their trimethylsilyl derivatives to optimize the GC–MS analysis. No centrifugation and disperser solvent were required in this Microextraction procedure. Significantly, short extraction time and high extraction efficiency were achieved. This method opens up a potentially new horizon for on-site dispersive liquid–liquid Microextraction. Under the optimum conditions, the proposed method provided good enrichment factors up to 310, with relative standard deviations ranging from 6.1 to 12.9%. The limits of quantification were in the range of 20–100 ng/L, depending on the analytes. The linearities were between 0.05 and 10 μg/L and 0.1 and 10 μg/L for different UV filters. Finally, the proposed method was successfully applied to the determination of UV filters from spiked genuine water samples and acceptable recoveries over the range of 71.0–120.0% were obtained.
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ionic liquid supported three phase liquid liquid liquid Microextraction as a sample preparation technique for aliphatic and aromatic hydrocarbons prior to gas chromatography mass spectrometry
Journal of Chromatography A, 2008Co-Authors: Chanbasha Basheer, Anass Ali Alnedhary, B Madhava S Rao, Rajasekhar Balasubramanian, Hian Kee LeeAbstract:For the first time hollow fiber-protected ionic liquid supported three-phase (liquid–liquid–liquid) Microextraction (HFM-LLLME) was developed for the gas chromatography-mass spectrometric (GC-MS) analysis of aromatic and aliphatic hydrocarbons. The hydrocarbons were extracted from 10 m1 of aqueous samples though small volumes of ionic liquid and organic solvent in the hollow fiber membrane HFM) wall and channel, respectively. The ionic liquid was immiscible with both the aqueous sample and the organic solvent (toluene). After extraction, the enriched solvent was directly injected into a GC-MS system for analysis without any further pretreatment. Ionic liquid supported HFM-LLLME shows better extraction performance than two-phase HFM-liquid-phase Microextraction, in which only organic solvent is involved, and solid-phase Microextraction. The ionic liquid and organic solvent combination found most suitable for HFM-LLLME was 1-butyl-3-methylimidazolium hexafluorophosphate, and toluene, respectively. This new technique provided up to 210-fold enrichment of aliphatic and aromatic hydrocarbons in 40 min with good reproducibility (<11%) and limits of detection (1–7 ng l−1).
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dynamic three phase Microextraction as a sample preparation technique prior to capillary electrophoresis
Analytical Chemistry, 2003Co-Authors: Li Hou, Hian Kee LeeAbstract:Dynamic three-phase (liquid−liquid−liquid) Microextraction was developed for capillary electrophoresis. Four aromatic amines as model compounds were extracted from 4-mL aqueous samples adjusted to basic condition (donor solution) through a small volume of organic solvent impregnated in a hollow fiber, which was held by the needle of a conventional syringe, and retracted into a 5-μL acidic acceptor solution inside the syringe. A renewable organic film and aqueous sample plug were formed inside the hollow fiber with the repeated movement of the syringe plunger enabled by a programmable syringe pump. This is believed to be the first reported instance of a semiautomated dynamic liquid−liquid−liquid Microextraction (LLLME) procedure. Following this Microextraction, the 5-μL acceptor solution was analyzed by capillary zone electrophoresis (CE). This new technique provided ∼140-fold enrichment in 20 min. Utilizing 4-chloroaniline as internal standard, dynamic LLLME could provide good reproducibility (<4.0%). In ...
Jacek Namieśnik - One of the best experts on this subject based on the ideXlab platform.
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green aspects developments and perspectives of liquid phase Microextraction techniques
Talanta, 2014Co-Authors: Agata Spietelun, łukasz Marcinkowski, Miguel De La Guardia, Jacek NamieśnikAbstract:Determination of analytes at trace levels in complex samples (e.g. biological or contaminated water or soils) are often required for the environmental assessment and monitoring as well as for scientific research in the field of environmental pollution. A limited number of analytical techniques are sensitive enough for the direct determination of trace components in samples and, because of that, a preliminary step of the analyte isolation/enrichment prior to analysis is required in many cases. In this work the newest trends and innovations in liquid phase Microextraction, like: single-drop Microextraction (SDME), hollow fiber liquid-phase Microextraction (HF-LPME), and dispersive liquid-liquid Microextraction (DLLME) have been discussed, including their critical evaluation and possible application in analytical practice. The described modifications of extraction techniques deal with system miniaturization and/or automation, the use of ultrasound and physical agitation, and electrochemical methods. Particular attention was given to pro-ecological aspects therefore the possible use of novel, non-toxic extracting agents, inter alia, ionic liquids, coacervates, surfactant solutions and reverse micelles in the liquid phase Microextraction techniques has been evaluated in depth. Also, new methodological solutions and the related instruments and devices for the efficient liquid phase micoextraction of analytes, which have found application at the stage of procedure prior to chromatographic determination, are presented.
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developments in ultrasound assisted Microextraction techniques for isolation and preconcentration of organic analytes from aqueous samples
Trends in Analytical Chemistry, 2013Co-Authors: Aleksandra Szreniawasztajnert, Bozena Zabiegala, Jacek NamieśnikAbstract:Abstract The great potential of ultrasonic assistance in sample preparation, especially extraction, is being recognized. In this review, we discuss the applications of ultrasonic radiation in assisting Microextraction. Topics covered include ultrasound-assisted emulsification Microextraction, ultrasound-assisted-emulsification-dispersive liquid-liquid Microextraction, and ultrasound-assisted hollow-fiber liquid-phase Microextraction with its modifications. We critically discuss the advantages and the limitations of each technique. Finally, we summarize recent practical applications.
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Current trends in solid-phase Microextraction (SPME) fibre coatings
Chemical Society Reviews, 2010Co-Authors: Agata Spietelun, Michał Pilarczyk, Adam Kloskowski, Jacek NamieśnikAbstract:This critical review presents information on known and innovative approaches to the manufacture of fibre coatings used in solid-phase Microextraction (SPME). The properties, advantages and drawbacks of the different types of commercially available SPME fibre coatings are discussed in detail, as are those of novel types of coatings and the methodologies of their preparation. The applications of fibre coatings in the solid-phase Microextraction of a broad spectrum of analytes are analysed, with particular emphasis on the sampling of polar analytes from polar matrices (174 references).
Junping Xiao - One of the best experts on this subject based on the ideXlab platform.
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trace determination of organophosphorus pesticides in environmental samples by temperature controlled ionic liquid dispersive liquid phase Microextraction
Journal of Chromatography A, 2008Co-Authors: Qingxiang Zhou, Junping XiaoAbstract:Abstract This paper described a new approach for the determination of organophosphorus pesticides by temperature-controlled ionic liquid dispersive liquid-phase Microextraction prior to high-performance liquid chromatography with ultraviolet detection. Methylparathion and phoxim, two of the typical organophosphorus pesticides, were used as the model analytes for the investigation of the development and application of the new Microextraction method. 1-Hexyl-3-methylimidazolium hexafluorophosphate [C6MIM][PF6] was used as the extraction solvent and the factors affecting the extraction efficiency such as the volume of [C6MIM][PF6], pH of working solutions, extraction time, centrifuging time, dissoluble temperature and salt effect were optimized. Under the optimal extraction conditions, methylparathion and phoxim exhibited good linear relationship in the concentration range of 1–100 ng mL−1. The detection limits were 0.17 ng mL−1 and 0.29 ng mL−1, respectively. Precisions of proposed method (RSDs, n = 6) were 2.5% and 2.7%, respectively. This proposed method was successfully applied in the analysis of four real environmental water samples and good spiked recoveries over the range of 88.2–103.6% were obtained. These results indicated that temperature-controlled ionic liquid dispersive liquid-phase Microextraction had excellent application prospect in environmental field.
