Development of a needle device for on-line electroextraction—liquid chromatography

Vlis, E. van der; Mazereeuw, M.; Tjaden, U.R.; Irth, H.; Greef, J. van der

doi:10.1016/0021-9673(96)00154-9

Cited by 26 publications

(14 citation statements)

References 4 publications

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“…In the final step (F), the capillary inlet is placed into the leading buffer and CZE is started by application of separation voltage. The method has been applied to preconcentration and determination of compounds of pharmaceutical relevance in standard solutions [19][20][21], applications to real biological samples were, however, not Generalshown in these papers. EE was also presented as a suitable pretreatment and preconcentration technique for HPLC [21].…”

Section: Systems With Two Immiscible Solventsmentioning

confidence: 96%

“…Determination of metal cations in biological samples was also shown using EME combined with CE-UV [115]. The acceptor solution with electroextracted heavy metals ions (Pb 21 and Zn 21 ) was mixed with EDTA solution and the formed chelates were determined by UV detection at 200 nm. No interference from other inorganic components of biological fluids forming chelates with EDTA, such as Mg 21 and Ca 21 , was observed for human serum, urine and amniotic fluid samples.…”

Section: E Ementioning

confidence: 99%

“…The acceptor solution with electroextracted heavy metals ions (Pb 21 and Zn 21 ) was mixed with EDTA solution and the formed chelates were determined by UV detection at 200 nm. No interference from other inorganic components of biological fluids forming chelates with EDTA, such as Mg 21 and Ca 21 , was observed for human serum, urine and amniotic fluid samples. Experimental conditions of the EME processes, materials and solvents for SLM membranes and analytes and matrices used for EME extractions are summarized in Table 2.…”

Section: E Ementioning

confidence: 99%

“…The convective mixing, which often accompanies the LLE, was suppressed since the thermal flows could not cross the phase interfaces. LiquidÀliquid EE has later been used as a sample preparation technique in CE and LC [19][20][21]. In order to allow the electric current to flow through the two immiscible liquid phases, the non-conductive organic phase was saturated with ionic species and EE was applied as a fast on-line sample pretreatment step for the two separation methods.…”

Section: Introductionmentioning

confidence: 99%

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Electric field‐enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis

2010

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Separation techniques, such as electrodialysis, electroextraction, electro-membrane extraction and extraction across phase interfaces, are reviewed and discussed as methods for sample cleanup and preconcentration. This survey clearly shows that electromigration of ionic species across phase interfaces, especially across supported liquid membranes, may be very selective and is strongly dependent on the chemical composition of these interfaces. Thus, electric field-enhanced transport across chemically tailored liquid membranes may open new perspectives in preparative analytical chemistry. This review offers comprehensive survey of related literature and discussion of the topic, which may stimulate interest of experts and practitioners in bioanalysis.

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Section: Systems With Two Immiscible Solventsmentioning

confidence: 96%

Section: E Ementioning

confidence: 99%

Section: E Ementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Electric field‐enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis

2010

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“…Van der Greef et al reported early attempts of analytical EE in the period 1994 -1996. [3][4][5] Three research papers demonstrated EE of charged substances from an organic solvent (ethyl acetate) and into aqueous solutions for subsequent analysis by CE or HPLC. Thus, conventional LLE was performed prior to EE when the technique was used for aqueous samples such as biological fluids.…”

Section: Introductionmentioning

confidence: 99%

Electromembrane Extraction from Biological Fluids

et al. 2011

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Online capillary liquid–liquid electroextraction of peptides as fast pre‐concentration prior to LC‐MS

et al. 2010

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In this research paper, we show that capillary electroextraction (cEE) is capable of fast online peptide concentration and that it can be coupled online to LC-MS to result in a fast and sensitive method. Electroextraction takes place when an electrical field is applied in a two-phase liquid-liquid system. Sample molecules in the organic phase migrate very fast into the aqueous phase and are concentrated in a small zone. In this work, cEE of peptides is developed and coupled online to LC-MS via a switching valve. Comparison of 10 min of cEE-LC-MS with a normal LC-MS injection showed more than 100-fold increased peak heights. Of five model peptides, good calibration curves in the range of 0.05-5 μmol/L were obtained. The linearity was good (R(2) values between 0.984 and 0.996) and RSD between 5% at the highest to 25% at the lowest concentration (n=3). The LOD of bradykinin, angiotensin I-converting enzyme inhibitor and angiotensin I was in the low nmol/L range. Analysis of a tryptic digest of eight model proteins resulted in more than 170 peptides, without bias for pI or hydrophilicity. Urine analysis is demonstrated, resulting in an LOD around 0.04 μmol/L urine for tryptic cytochrome C peptides spiked to urine and an increase of 42% in the number of chromatographic peaks compared with the conventional LC-MS. In summary, cEE-LC-MS is a fast electrophoresis-driven sample preconcentration technique that is quantitative, able to extract a wide peptide range and applicable to bioanalysis.

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Development of a needle device for on-line electroextraction—liquid chromatography

Cited by 26 publications

References 4 publications

Electric field‐enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis

Electric field‐enhanced transport across phase boundaries and membranes and its potential use in sample pretreatment for bioanalysis

Electromembrane Extraction from Biological Fluids

Online capillary liquid–liquid electroextraction of peptides as fast pre‐concentration prior to LC‐MS

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