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Michel M, Chimuka L, Kowalkowski T, Cukrowska EM, Buszewski B. Prediction of extraction efficiency in supported liquid membrane with a stagnant acceptor phase by means of artificial neural network. J Sep Sci 2013; 36:986-91. [PMID: 23378188 DOI: 10.1002/jssc.201200105] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 11/07/2012] [Accepted: 11/15/2012] [Indexed: 11/06/2022]
Abstract
An artificial neural network model of supported liquid membrane extraction process with a stagnant acceptor phase is proposed. Triazine herbicides and phenolic compounds were used as model compounds. The model is able to predict the compound extraction efficiency within the same family based on the octanol-water partition coefficient, water solubility, molecular mass and ionisation constant of the compound. The network uses the back-propagation algorithm for evaluating the connection strengths representing the correlations between inputs (octanol-water partition coefficients logP, acid dissociation constant pK(a), water solubility and molecular weight) and outputs (extraction efficiency in dihexyl ether and undecane as organic solvents). The model predicted results in good agreement with the experimental data and the average deviations for all the cases are found to be smaller than ±3%. Moreover, standard statistical methods were applied for exploration of relationships between studied parameters.
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2
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On-line coupling of a clean-up device with supported liquid membrane to capillary electrophoresis for direct injection and analysis of serum and plasma samples. J Chromatogr A 2012; 1234:2-8. [DOI: 10.1016/j.chroma.2011.10.046] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2011] [Revised: 10/13/2011] [Accepted: 10/17/2011] [Indexed: 11/19/2022]
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3
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Zhao W, Jusys Z, Behm RJ. Quantitative online analysis of liquid-phase products of methanol oxidation in aqueous sulfuric acid solutions using electrospray ionization mass spectrometry. Anal Chem 2010; 82:2472-9. [PMID: 20163128 DOI: 10.1021/ac902847a] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We describe a novel method and setup for quantitative online analysis of the liquid-phase methanol oxidation products in acidic aqueous solutions by electrospray ionization mass spectrometry (ESI-MS). This includes a specially designed flow system, which allows continuous online mixing, derivatization, extraction, separation, and quantitative detection within ca. 3 min. For electrospray ionization of formaldehyde, it is first online-derivatized by 2,4-dinitrophenyl hydrazine to form the easily ionizable 2,4-dinitrophenyl hydrazone. Then, both formic acid and derivatized formaldehyde are online extracted into an immiscible organic phase, which, after separation from the aqueous phase, is piped to the ESI-MS for analysis. This strategy ensures complete removal of the highly corrosive sulfuric acid from the analyte and allows the liquid-phase methanol oxidation reaction (MOR) products (formaldehyde and formic acid) to be quantitatively detected by ESI-MS. Finally, the potential of this method for online analysis in electroanalysis and electrocatalysis is discussed.
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Affiliation(s)
- W Zhao
- Institute of Surface Chemistry and Catalysis, Ulm University, D-89069 Ulm, Germany
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Ali I, Gupta V, Aboul‐Enein HY, Hussain A. Hyphenation in sample preparation: Advancement from the micro to the nano world. J Sep Sci 2008; 31:2040-53. [DOI: 10.1002/jssc.200800123] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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5
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Hyötyläinen T. On-line coupling of extraction with gas chromatography. J Chromatogr A 2008; 1186:39-50. [DOI: 10.1016/j.chroma.2007.11.066] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2007] [Revised: 11/08/2007] [Accepted: 11/15/2007] [Indexed: 11/30/2022]
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Hyötyläinen T. Principles, developments and applications of on-line coupling of extraction with chromatography. J Chromatogr A 2007; 1153:14-28. [PMID: 17196971 DOI: 10.1016/j.chroma.2006.11.102] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2006] [Revised: 11/21/2006] [Accepted: 11/29/2006] [Indexed: 11/27/2022]
Abstract
On-line coupling of extraction and chromatographic separation allows the whole analysis to be performed in a closed system. On-line systems are particularly useful when the analytes are labile, the amount of sample is limited, or very high sensitivity is required. Many on-line systems have been developed both for liquid and for solid samples. This review discusses the different instruments that have been constructed and the factors that need to be considered in the coupling. Selected illustrative applications are described to illustrate the potential of the on-line systems.
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Affiliation(s)
- Tuulia Hyötyläinen
- University of Helsinki, Department of Chemistry, Laboratory of Analytical Chemistry, P.O. Box 55, FIN-00014 University of Helsinki, Finland.
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Kloskowski A, Chrzanowski W, Pilarczyk M, Namiesnik J. Modern Techniques of Sample Preparation for Determination of Organic Analytes by Gas Chromatography. Crit Rev Anal Chem 2007. [DOI: 10.1080/10408340600976663] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Adam Kloskowski
- a Department of Physical Chemistry , Gdansk University of Technology , Gdansk, Poland
| | - Wojciech Chrzanowski
- a Department of Physical Chemistry , Gdansk University of Technology , Gdansk, Poland
| | - Michał Pilarczyk
- a Department of Physical Chemistry , Gdansk University of Technology , Gdansk, Poland
| | - Jacek Namiesnik
- b Department of Analytical Chemistry , Gdansk University of Technology , Gdansk, Poland
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Barri T, Bergström S, Norberg J, Jönsson JA. Miniaturized and Automated Sample Pretreatment for Determination of PCBs in Environmental Aqueous Samples Using an On-Line Microporous Membrane Liquid−Liquid Extraction-Gas Chromatography System. Anal Chem 2004; 76:1928-34. [PMID: 15053653 DOI: 10.1021/ac035089g] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new, fast, and automated sample pretreatment technique for determination of lipophilic organic compounds in aqueous samples has been developed and applied to the determination of polychlorinated biphenyls (PCBs) in environmental river water. It is based on miniaturized microporous membrane liquid-liquid extraction coupled on-line to gas chromatography (GC) with electron capture detection. The heart of the system that simultaneously connects the sample pretreatment step to the final GC analysis has been named the extracting syringe (ESy). The ESy carries a miniaturized membrane extraction card attached to an electrically and mechanically designed installment and is mounted directly over a GC injector for fully automated injection of the extract. A method was developed to extract 10 PCB congeners from 1-mL water samples (after addition of 40% acetonitrile) with an extraction time of 10 min. The optimized methodology showed good linearity (in the dynamic concentration range of 5 ng L(-)(1)-1 microg L(-)(1)), enrichment factors of 33-40 times, repeatable extractions (RSD 2-5%, n = 4), and low detection limits (2-3 ng L(-)(1)). Acetonitrile had to be added to the samples in order to overcome the influence of PCB adsorption on the repeatability of extraction and enrichment and to minimize the overall memory effect (OME). OME and carryover depended not only on the concentration of the organic solvent added to the sample and that used in the washing procedure but also on whether the extracting card was changed or not. When an optimized washing procedure was applied, the OME was approximately 0.2% at high concentrations (i.e., 1 microg L(-)(1)). When each extraction took place in a new extraction card, no OME was detected. Additionally, no significant adsorption onto glass surfaces or a matrix effect on extraction was noticed. The main features of this methodology are good extraction repeatability, low detection limits at short extraction time, and the unsurpassed characteristic of no detectable OME in the entire system when each sample is processed in a new card. The total consumption of organic (nonchlorinated) solvents is less than 5 mL per sample.
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Affiliation(s)
- Thaer Barri
- Department of Analytical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
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Kou D, Mitra S. Simultaneous Extraction and Concentration by On-Line Hollow Fiber Membrane Extraction. Anal Chem 2003; 75:6355-60. [PMID: 14616022 DOI: 10.1021/ac030071r] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the determination of trace-level pollutants in water, a concentration step is usually needed between extraction and analysis. In this paper, simultaneous extraction and concentration during on-line analysis using hollow fiber membranes is reported. Solvent loss across the membrane resulted in simultaneous concentration during extraction and had pronounced influence on enrichment factor and extraction efficiency. This phenomenon is an important consideration for analytical methods employing solvent extraction across a membrane, because it is possible to eliminate the concentration step. Continuous on-line monitoring of semivolatile compounds was achieved using this approach, and the effects of process variables on enrichment and extraction efficiency were studied. It was found that enrichment increased with solvent loss, even when the extraction efficiency decreased.
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Affiliation(s)
- Dawen Kou
- Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102, USA
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Dawidowicz AL, Kalityński R, Trocewicz J, Nestorowicz A, Fijałkowska A, Trela-Stachurska K. Investigation of propofol renal elimination by HPLC using supported liquid membrane procedure for sample preparation. Biomed Chromatogr 2002; 16:455-8. [PMID: 12378557 DOI: 10.1002/bmc.183] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
One of the least explored subjects in the research on the metabolism of a widely used anaesthetic, propofol, is its excretion in an unchanged form. According to literature, the estimated percentage of applied propofol eliminated intact via kidneys is lower than 0.3%. The present study shows the amount of propofol excreted in an unchanged form with urine collected during the first 48 h after anaesthesia in five patients undergoing elective intracranial procedures. The drug was concentrated and selectively isolated from urine samples by supported liquid membrane technique and determined by HPLC with fluorescence detection. The amount of unchanged propofol eliminated with urine was approximately (0.004 +/- 0.002)% of the total applied dose. The obtained results may suggest that propofol in an unchanged form is not excreted by kidneys at all provided that all propofol determined in presented study originated from conjugates hydrolysis.
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Affiliation(s)
- Andrzej L Dawidowicz
- Department of Chemical Physics and Physicochemical Separation Methods, Faculty of Chemistry, Maria Curie-Skłodowska University, PL 20-031 Lublin, Maria Curie-Skłodowska Sq. 3, Poland.
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Chapter 15 Liquid membrane techniques. ACTA ACUST UNITED AC 2002. [DOI: 10.1016/s0166-526x(02)80052-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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12
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El-Hawary WF. Determination of lignocaine and amprolium in pharmaceutical formulations using AAS. J Pharm Biomed Anal 2002; 27:97-105. [PMID: 11682215 DOI: 10.1016/s0731-7085(01)00514-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The ion-associate complexes of lignocaine hydrochloride (Lig.Cl) with ammonium reineckate (Rk) or sodium cobaltithiocyanate, and that of amprolium hydrochloride (Amp.Cl) with ammonium reineckate, have been prepared. The precipitated ion-associates were subjected to elemental analyses, infrared and nuclear magnetic resonance spectroscopy and determination of the metal content for elucidation of their structures. The solubilities of the solid ion-associate complexes have been studied and their solubility products were determined at different temperatures at the optimum pH for their quantitative precipitation. The thermodynamic parameters DeltaH, DeltaG and DeltaS for the dissolution of the ion-associate complexes were calculated. These ion-associate complexes have been used for the quantitative determination of the above mentioned drugs by precipitating them with an excess of the inorganic metal complex ions and determining the excess metal complex ions using atomic absorption spectrometry. The method was applied for the determination of the above drugs in pure solution and pharmaceutical preparations. 0.135-135.4 and 0.158-157.6 mg of lignocaine and amprolium, respectively, can be determined with mean relative standard deviations (R.S.D.) 0.92-1.20% and recovery values of 99.18+/-0.48 to 100.12+/-0.34% indicating high precision and accuracy.
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Affiliation(s)
- W F El-Hawary
- Chemistry Department, Faculty of Science, Cairo University, Giza, Egypt
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Cordero BM, Pérez Pavón JL, García Pinto C, Fernández Laespada ME, Carabias Martínez R, Rodriguez Gonzalo E. Analytical applications of membrane extraction in chromatography and electrophoresis. J Chromatogr A 2000; 902:195-204. [PMID: 11192155 DOI: 10.1016/s0021-9673(00)00835-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An overview of the analytical applications of membrane-based systems for sample enrichment in chromatography and capillary electrophoresis is presented. A brief introduction to the different types of membranes and the main forces related to the transport through them is also given.
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Affiliation(s)
- B M Cordero
- Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de Salamanca, Spain.
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Abstract
Sample preparation techniques based on non-porous membrane extraction generally offer a high degree of selectivity and enrichment power, together with convenient possibilities for direct and automated connections to chromatographic and other analytical instruments. In this review principles and applications for techniques as supported liquid membrane extraction, microporous membrane liquid-liquid extraction, polymeric membrane extraction and membrane extraction with a sorbent interface are described and compared.
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Affiliation(s)
- J A Jönsson
- Department of Analytical Chemistry, Lund University, Sweden.
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Jönsson JA, Andersson M, Melander C, Norberg J, Thordarson E, Mathiasson L. Automated liquid membrane extraction for high-performance liquid chromatography of Ropivacaine metabolites in urine. J Chromatogr A 2000; 870:151-7. [PMID: 10722072 DOI: 10.1016/s0021-9673(99)00971-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An automatic method for the determination of metabolites of Ropivacaine in urine was set up. It utilizes supported liquid membrane extraction for sample clean-up and enrichment, followed by ion-pair chromatography determination using UV detection. The extraction was very selective with no observed interfering compounds from the urine matrix, permitting simple isocratic chromatographic analysis. The detection limits for spiked urine samples were 2-18 nM for the different compounds. The repeatability was 1-3% (RSD) with an internal standard that was also extracted, and about twice without this standard. A throughput of 3.3 samples per hour was achieved and the liquid membrane was stable for more than a week.
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Affiliation(s)
- J A Jönsson
- Department of Analytical Chemistry, Lund University, Sweden.
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van de Merbel NC. Membrane-based sample preparation coupled on-line to chromatography or electrophoresis. J Chromatogr A 1999; 856:55-82. [PMID: 10526784 DOI: 10.1016/s0021-9673(99)00581-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A review on the use of membranes for on-line sample preparation prior to chromatographic and electrophoretic analysis is provided. The current state-of-the-art of four membrane-based techniques (dialysis, electrodialysis, filtration and membrane extraction) is described by reviewing their principles and applications. Possible future developments are discussed.
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Shen Y, Jönsson JA, Mathiasson L. On-line microporous membrane liquid-liquid extraction for sample pretreatment combined with capillary gas chromatography applied to local anaesthetics in blood plasma. Anal Chem 1998; 70:946-53. [PMID: 9511470 DOI: 10.1021/ac971052i] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A new automated procedure for analyzing complex samples has been developed utilizing microporous membrane liquid-liquid extraction (MMLLE) combined with capillary gas chromatography. Some local anaesthetics were used as model compounds in aqueous solution as well as in blood plasma. The MMLLE procedure was performed in a flow system with the sample fed to the donor side of the hydrophobic microporous membrane and with an organic solvent (hexane) in the pores and as the acceptor solution. The analytes in a small volume of sample (< 1 mL) were extracted into the organic acceptor phase which was transferred into the gas chromatographic system by utilizing a loop-type interface compatible with large-volume (300 microL) injection. High selectivity and low carry-over effects were obtained with the system. The detection limits were 0.5-1 ng/mL using 0.5 mL of human plasma, and the precision was approximately 5%. The effects of pH, flow rates, and adsorption of the analytes were evaluated.
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Affiliation(s)
- Y Shen
- Department of Analytical Chemistry, Lund University, Sweden
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