Simultaneous analysis of lead, mercury and selenium species by capillary electrophoresis with combined ethylenediaminetetraacetic acid complexation and field-amplified stacking injection

Liu, Wuping; Lee, Hian Kee

doi:10.1002/(sici)1522-2683(19990801)20:12<2475::aid-elps2475>3.0.co;2-m

Cited by 24 publications

(6 citation statements)

References 36 publications

(26 reference statements)

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“…Based on the reported references, 4,8,10,39,40 some CE systems with different terms of the separation mode and back ground electrolyte (BGE) composition were compared for the separation of metal-EDTA complexes: i) 7.5 mM salicylic acid + 0.1 mM EDTA + 0.02 mM hexadecyltrimethylammonium bromide (HTAB), pH 4.01;…”

Section: Separation Mode and Back Ground Electrolytementioning

confidence: 99%

“…[4][5][6][7] Ethylenediaminetetraacetic acid (EDTA) has also been used for this purpose. [8][9][10][11] EDTA is known to complex with metal ions in a 1:1 ratio, and the chelates are always negalively charged whatever the charge on the cations. 4,12 As a principally electrophoretic property, metal-EDTA anionic complexes could be successfully separated due to inherent differences in the electrophoretic mobilities.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Determination of Pb(II), Cu(II) and Fe(III) with Capillary Electrophoresis Using Ethylenediaminetetraacetic Acid as a Complexing Agent and Vancomycin as a Complex Selector

2006

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IntroductionIn the past decades, capillary electropheresis (CE) has been considered to be a powerful method, and widely applied to analyze many of different substances, ranging from small inorganic ions to large bio-macromolecules, due to many advantages, such as high separation speed and efficiency, very low running costs and low sample volume injected (e.g., 2 -10 nl). Metal-ion analysis, 1-3 however, covers a relatively small part of CE applications compared with separations in the areas of pharmaceuticals, oligonucleotides, proteins and peptides. Considering metal-ion analysis, problems occur due to (i) the similar electrophoretic mobilities and (ii) the weak UV absorption of most metal ions.The former problem is because most transition metal ions have similar mobilities due to their similar size and identical charge. 4 To achieve an electrophoretic separation, the mobilities have to be modified by introducing a complex forming equilibrium. If different degrees of complexation result for the ions during the interaction with a ligand, their apparent electrophoretic mobilities should also be different. Various reports can be found in the literature describing organic acids as complexing agents for improving the resolution in CE separation. These include oxalic acid, lactic acid, tartaric acid and hydroxyisobutyric acid. [4][5][6][7] Ethylenediaminetetraacetic acid (EDTA) has also been used for this purpose. [8][9][10][11] EDTA is known to complex with metal ions in a 1:1 ratio, and the chelates are always negalively charged whatever the charge on the cations. 4,12 As a principally electrophoretic property, metal-EDTA anionic complexes could be successfully separated due to inherent differences in the electrophoretic mobilities. However, in practice, it also suffers from poor selectivities, and is not sensitive. Until now, on-column derivatization, also called in-capillary derivatization, has been applied to determine various types of analyte by one of three different strategies: zone-passing, at-inlet and throughout capillary derivatization. 2,8,[13][14][15] These studies have proven that the sensitivity could be sharply increased by using in-capillary derivatization.For the latter problem, the weak UV-absorption of most metal ions, several preconcentration methods have been developed to overcome the sensitivity problem, such as isotachophoresis, 16 [28][29][30] In addition, the sensitivity for the metal determination could be improved by using on-line preconcentration in micellar electrokinetic chromatography 45 and CE-laser induced fluorescence. 46 Increasing the optical path length by incorporating a bubble cell 31,32 or a U-shaped cell 33,34 is one of the means to improve the sensitivity of a UV detector. U-shaped cells, usually a bent capillary, with a few millimeters of the capillary parallel to the optical path, can provide a higher sensitivity, but a loss of resolution prevents this method from further development. 35 Vancomycin is a macrocyclic antibiotic containing in its structure 18 asymmetric cent...

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Section: Separation Mode and Back Ground Electrolytementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of Pb(II), Cu(II) and Fe(III) with Capillary Electrophoresis Using Ethylenediaminetetraacetic Acid as a Complexing Agent and Vancomycin as a Complex Selector

2006

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“…Several sample stacking variations have been developed for the analysis of anionic and cationic species [29,32,[65][66][67][68][69][70][71]. For instance, Liu and Lee [67] reported an enhancement of detection up to 1700-fold for multiple species of lead, mercury and selenium with field-amplified stacking injection (FASI), and sub-mg/L detection limits were obtained.…”

Section: Sample Stacking and Sweepingmentioning

confidence: 99%

“…For instance, Liu and Lee [67] reported an enhancement of detection up to 1700-fold for multiple species of lead, mercury and selenium with field-amplified stacking injection (FASI), and sub-mg/L detection limits were obtained. More recently, Timerbaev et al [70] evaluated on-capillary approaches for the improvement of detection sensitivity for UV-absorbing anions in samples of high salt content such as seawater.…”

Section: Sample Stacking and Sweepingmentioning

confidence: 99%

Recent advances in capillary electrophoresis and capillary electrochromatography of pollutants

2001

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An overview of major developments in capillary electrophoresis and capillary electrochromatography systems in the environmental field is presented, covering relevant publications between the second half of 1999 and early 2001. Contributions are reviewed in relation to developments in detection, sample preparation/preconcentration, precision and applications. Many interesting examples are shown and the influence of important parameters on the performance of developed methods is discussed.

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“…The determination of transition metals using a HQS chelating system was developed by Timerbaev et al [11,20]. Ethylenediaminetetraacetic, diethylene-triaminepentaacetic and cyclohexane-1,2-diaminetetraacetic acids had been investigated and the results obtained were compared in order to optimize the resolution for the separation and determination of complexed metal ions [7,[21][22][23]. The problem of using the strong complex approach is that only a limited number of metals can form a strong complex with a given chelating agent and the detection sensitivity is highly dependent on the formation of chelates with strong chromophores [20][21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Determination of trace metals by capillary electrophoresis

Fung

Lau

2001

Electrophoresis

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A new analytical procedure is developed using a strong complexing agent, 1,10-phenanthroline (Phen), for direct UV detection of Zn, Mn, Cu, Co, Cd, and Fe at microg/L concentrations in environmental water samples. The metal chelates formed showed different electrophoretic mobilities and solved the comigration problem for capillary electrophoresis (CE) separation of free metal ions. To obtain stable metal-Phen chelates during the capillary zone electrophoresis (CZE) run, both pre-column and on-column complexation are required and threefold excess of Phen over metal ions should be added to the sample. The optimized background electrolyte (BGE) consists of 30 mM hydroxylamine hydrochloride and 0.1% methanol at pH 3.6. Under hydrodynamic sampling, CE run at + 20 kV in 65 cm x 0.05 mm ID fused-silica column with detection at 265 nm, baseline separation, satisfactory working ranges (10 microg/L to 5.5 mg/L), sensitive detection limits (1-3 microg/L), good repeatability for migration times (relative standard deviation, RSD 0.36-0.81%, n = 5), peak area (RSD 3.2-4.2%, n = 5) and peak height (RSD 3.2-4.5%, n = 5) were obtained for the metal cations investigated. The reliability of the method was established by parallel determination using the inductively coupled plasma-atomic emission spectrometry (ICP-AES) method giving results within statistical variation. The procedure developed is shown to provide a quick, sensitive, precise, and economic method for simultaneous determination of metal cations that can form stable chelates with Phen.

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Simultaneous analysis of lead, mercury and selenium species by capillary electrophoresis with combined ethylenediaminetetraacetic acid complexation and field-amplified stacking injection

Cited by 24 publications

References 36 publications

Determination of Pb(II), Cu(II) and Fe(III) with Capillary Electrophoresis Using Ethylenediaminetetraacetic Acid as a Complexing Agent and Vancomycin as a Complex Selector

Determination of Pb(II), Cu(II) and Fe(III) with Capillary Electrophoresis Using Ethylenediaminetetraacetic Acid as a Complexing Agent and Vancomycin as a Complex Selector

Recent advances in capillary electrophoresis and capillary electrochromatography of pollutants

Determination of trace metals by capillary electrophoresis

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