Simultaneous analysis of inorganic and organic lead, mercury and selenium by capillary electrophoresis with nitrilotriacetic acid as derivatization agent

Liu, Wuping; Lee, Hian Kee

doi:10.1016/s0021-9673(97)01012-1

Cited by 41 publications

(21 citation statements)

References 19 publications

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“…As can be seen from Table 1, the DLLME-BE assisted to obtaining 4 and 16 times higher sensitivity, 12 times higher EF in a shorter time than those of dCPE and SPE, all three followed by CZE-UV detection [35,38]. Furthermore, using the same UV detection, the presented sensitivity was even above 2 orders of magnitude higher than that of off-column derivatization [46]. Several CE-UV applications after sample stacking also referenced in two recent reviews [14,15], show the same or even better sensitivity and EF for Hg 2+ , respectively, such as 0.14 μg L −1 and 813 using FASI [34], and 0.03 μg L −1 and 4580 using HF-LLLME-LVSS [40], using longer migration time (Table 1).…”

Section: +mentioning

confidence: 86%

Determination of mercury(II) in water samples using dispersive liquid-liquid microextraction and back extraction along with capillary zone electrophoresis

Lü

et al. 2011

Microchim Acta

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We have developed a method for the determination of mercury in water samples that combines dispersive liquid-liquid microextraction (DLLME) with backextraction (BE) and detection by capillary zone electrophoresis. DLLME is found to be a simple, cost-effective and rapid method for extraction and preconcentration. The BE procedure is based on the fact that the stability constant of the hydrophilic chelate of Hg(II) with Lcysteine is much larger than that of the respective complex with 1-(2-pyridylazo)-2-naphthol. Factors affecting complex formation and extraction efficiency (such as pH value, concentration of the chelating agent, time of ultrasonication and extraction, and type and quantity of disperser solvent) were optimized. Under the optimal conditions, the enrichment factor is 625, and the limit of detection is 0.62 μg L −1 . The calibration plot is linear in the range between 1 and 1,000 μg L −1 (R 2 =0.9991), and the relative standard deviation (RSD, for n=6) is 4.1%. Recoveries were determined with tap water and seawater spiked at levels of 10 and 100 μg L −1 , respectively, and ranged from 86.6% to 95.1%, with corresponding RSDs of 3.95-5.90%.

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Section: +mentioning

confidence: 86%

Determination of mercury(II) in water samples using dispersive liquid-liquid microextraction and back extraction along with capillary zone electrophoresis

Lü

et al. 2011

Microchim Acta

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“…The molar absorption coefficients of L and Ln-L complexes were obtained as 2.46 10 4 cm 21 mol 21 dm 3 at 469 nm. It is noted that larger coefficients and the longer absorption wavelengths were observed than with other polyaminocarboxylate reagents used in previously reported CE experiments, such as EDTA [9,[23][24][25][26], trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (CyDTA) [27], nitrilotriacetic acid [28], triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid (TTHA) [29] and 8-amino-2-[(2-amino-5-methylphenoxy)methyl]-6-methoxyquinoline-N,N,N',N'-tetraacetate [14], which made the absorbance CE detection more sensitive and selective. …”

Section: Spectroscopic Property Of L and Ln-l Complexesmentioning

confidence: 83%

Highly sensitive determination of lanthanides by capillary electrophoresis with direct visible detection after precapillary complexation with aromatic polyaminocarboxylate and additionally applying dynamic ternary complexation with nitrilotriacetic acid

2006

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A newly synthesized aromatic polyaminocarboxylate (NBD-ABEDTA, H(4)L) was applied to precapillary derivatizing capillary electrophoresis as a chelating reagent for lanthanide ions (Ln(3+)). The Ln-L complexes provide both kinetic stability on dissociation due to their methyl-EDTA coordinating structure, and high light absorptivity (epsilon(max) = 2.4 x 10(4) cm(-1) mol(-1) dm(3)) in the visible region at 469 nm thanks to their nitrobenzofurazan moiety. A ligand was employed for capillary zone electrophoresis based on a unique concept: both precapillary and dynamic on-capillary complexation were carried out on one center-metal ion to achieve high resolution. As a ternary complex-formation agent, iminodiacetate (IDA), bound to the mother complex (Ln-L), was added to the carrier buffer solution. The carrier buffer solution of 9.5 mmol.dm(-3) (pH 9.45) borate and 33.5 mmol.dm(-3) IDA, drastically improved the resolution among Ln(3+) ions. Each of the Ln complexes was effectively separated, except for Pr-Sm. Furthermore, the absence of L from the carrier solution, which stabilizes the baseline fluctuation, provided low LOD (typically 4.2 x 10(-7) mol.dm(-3)). This strongly suggests that Ln-L complexes are kinetically stable even with a large excess of IDA. Quite unexpectedly, the order of migration differs from that of the atomic number, inverting at Nd. This is due to the effect of the cavity size of the residual coordination sites on the ternary complexation and the electronic density of Ln(3+).

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“…is another option for differentiation and determination of metal species. In a series of papers by Liu and Lee [31][32][33], the use of various complexones was investigated for a range of metals including mercury. The metals and their organometalic compounds form UV-absorbing complexes with the respective complexones.…”

Section: Complexonesmentioning

confidence: 99%

“…These complexes are electrophoretically separated and detected at a selected wavelength. In the first paper [31], only inorganic Hg(I) and Hg(II) species were separated in an electrolyte consisting of 40 mM phosphate-borate electrolyte with 40 mM SDS and 7.5 mM NTA. The detection limits were 0.1 and 0.3 mg/L for Hg(I) and Hg(II), respectively.…”

Section: Complexonesmentioning

confidence: 99%

Mercury speciation by CE: A review

et al. 2007

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CE methods for the speciation of inorganic and organomercury compounds are reviewed. Sample preparation, separation conditions and detection modes are discussed. Efficient separation and sensitive determination of mercury species by CE typically involves complexation with various thiols, chromogenic and other chelating agents; however, some methods do not require complexation. Spectrophotometric detection based on UV-visible absorption is by far the most commonly used. Hyphenated techniques, such as CE/inductively coupled plasma (ICP)-MS, hydride generation coupled to ICP-MS or atomic fluorescence spectrometry and CE/atomic absorption spectrometry are gaining popularity due to their high sensitivity and selectivity. Last, but not least, the potential and applications of electrochemical methods for detection of separated mercury species are outlined.

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Simultaneous analysis of inorganic and organic lead, mercury and selenium by capillary electrophoresis with nitrilotriacetic acid as derivatization agent

Cited by 41 publications

References 19 publications

Determination of mercury(II) in water samples using dispersive liquid-liquid microextraction and back extraction along with capillary zone electrophoresis

Determination of mercury(II) in water samples using dispersive liquid-liquid microextraction and back extraction along with capillary zone electrophoresis

Highly sensitive determination of lanthanides by capillary electrophoresis with direct visible detection after precapillary complexation with aromatic polyaminocarboxylate and additionally applying dynamic ternary complexation with nitrilotriacetic acid

Mercury speciation by CE: A review

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