Optimization of some experimental parameters in the electro membrane extraction of chlorophenols from seawater

Lee, Jingyi; Khalilian, Faezeh; Bagheri, Habib; Lee, Hian Kee

doi:10.1016/j.chroma.2009.09.037

Cited by 121 publications

(84 citation statements)

References 27 publications

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“…In this study, the effect of w was investigated using solutions containing 5, 10 and 15% NaCl. The obtained results are in full agreement with previous studies [37,38]. Thus, migration of the analytes would be more efficient in the absence of salt and all of the subsequent experiments in EME were performed in the absence of salt.…”

supporting

confidence: 93%

“…As predicted by the theoretical model [37], maximum response can be obtained in the minimum value of w. According to previous studies [37,38], the presence of high content of ionic substances causes an increase in the value of the w in the solution, which in turn decreases the flux of analytes across the SLM. In this study, the effect of w was investigated using solutions containing 5, 10 and 15% NaCl.…”

Section: Salt Effectmentioning

confidence: 92%

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Electromembrane extraction combined with cyclodextrin‐modified capillary electrophoresis for the quantification of trimipramine enantiomers

et al. 2012

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A sensitive, simple and reproducible method was developed for preconcentration and determination of trimipramine (TPM) enantiomers in biological samples using electromembrane extraction combined with cyclodextrin-modified capillary electrophoresis (CE). During the extraction, TPM enantiomers migrated from a 5 mL sample solution through a thin layer of 2-nitrophenyl octyl ether NPOE immobilized in the pores of a hollow fiber, and into a 20 μL acidic aqueous acceptor phase presented inside the lumen of the fiber. A Box-Behnken design and the response surface methodology (RSM) were used for the optimization of different variables on extraction efficiency. Optimized extraction conditions were: NPOE as supported liquid membrane, inter-electrode distance of 5 mm, stirring rate of 1000 rpm, 51 V potential difference, 34 min as the extraction time, acceptor phase pH 1.0 and donor phase pH 4.5. Then, the extract was analyzed using optimized cyclodextrin (CD)-modified CE method for the separation of TPM enantiomers. Best results were achieved using 100 mM phosphate running buffer (pH 2.0) containing 10 mM α-CD as the chiral selector, applied voltage of 18 kV and 20°C. The range of quantitation for both enantiomers was 20-500 ng/mL. The method was very reproducible so that intra- and interday RSDs (n=6) were <6%. The limits of quantitation and detection for both enantiomers were 20 and 7 ng/mL, respectively. Finally, this method was successfully applied to determine the concentration of TPM enantiomers in plasma and urine samples without any pre-treatment.

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supporting

confidence: 93%

Section: Salt Effectmentioning

confidence: 92%

Electromembrane extraction combined with cyclodextrin‐modified capillary electrophoresis for the quantification of trimipramine enantiomers

et al. 2012

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“…In contrast to earlier EME (Gjelstad et al 2006;PedersenBjergaard and Rasmussen 2006;Balchen et al 2007Balchen et al , 2008Gjelstad et al 2007a,b;Pedersen-Bjergaard and Rasmussen 2007;Kjelsen et al 2008;Middelthon-Bruer et al 2008;Xu et al 2008;Lee et al 2009;Petersen et al 2009), where each SLM was used only for a single extraction and then discarded, the same SLM was used for several extractions in the present work. Typically a single extraction cell could be used the whole day and with an RSD in the extraction performance of less than 5% for extractions performed under similar conditions To circumvent potential carryover from extraction to extraction with the chip EME system, the acceptor reservoir was rinsed with 7 ll of 10 mM HCl prior to each extraction.…”

Section: Slm Stability and Potential Memory Effectsmentioning

confidence: 88%

“…The advantage of EME for selective extraction and enrichment of nerve agent degradation products from river water and chlorophenols from seawater has recently been demonstrated by the group of Lee (Xu et al 2008;Lee et al 2009). In EME using porous hollow fibers, target analytes are extracted as charged species from an aqueous sample, typically with a volume of 100-300 ll, through a thin film of organic solvent immobilized in the pores of the porous hollow fiber (supported liquid membrane = SLM), and back into an aqueous acceptor solution placed inside the lumen of the hollow fiber.…”

Section: Introductionmentioning

confidence: 96%

On-chip electro membrane extraction

Petersen

Jensen

Hansen

et al. 2010

Microfluid Nanofluid

128

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This paper presents the first downscaling of electro membrane extraction (EME) to a chip format. The voltage-controlled extraction for sample preparation on microfluidic devices has several advantages such as selective extraction removing the high ionic strength of biological samples, preconcentration, fast kinetics with exact control of the beginning, and termination of the extraction. The device comprises a 25 lm thick porous polypropylene membrane bonded in-between two polymethyl methacrylate (PMMA) substrates with channel structures toward the membrane. The supported liquid membrane (SLM) was created by locally filling the pores of the membrane with 2-nitrophenyl octyl ether (NPOE). The sample solution, containing five basic model analytes in 10 mM HCl or urine was pumped through the 50 lm deep donor channel on one side of the membrane. With 15 V applied across the membrane, the protonated basic drugs were selectively extracted from the flowing sample solution, into the organic phase SLM, and further into just 7 ll of 10 mM HCl, serving as acceptor solution. Subsequently, the acceptor solution was analyzed by capillary electrophoresis. The electro membrane chip was highly efficient and even with flow rates resulting in the sample being in contact with the SLM for less than 4 s (3 ll min -1 ), 20-60% of the amount of the respective drugs in the sample was extracted. The large span in recovery was dependent on the physical properties of the drug substances compared to the SLM, and the individual drug substances were extracted with a RSD in the recovery of less than 5%.

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“…Another paper from the same group focused on EME of chlorophenols from seawater. 39 In the latter work, EME was conducted with 1-octanol as SLM, for 10 min, utilizing a 10-V driving force, and with NaOH pH 12 as acceptor phase. Finally, this group also demonstrated simultaneous extraction of acidic and basic drugs at neutral pH utilizing a compartmentalized membrane envelope.…”

Section: Other Recent Eme Papersmentioning

confidence: 99%