Capillary electrophoretic separation of inorganic and organic arsenic compounds

Greschonig, H.; Schmid, Martin G.

doi:10.1007/s002160051063

Cited by 18 publications

(8 citation statements)

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“…For example, the electrophoretic mobility of arsenate (pK a values 2.3, 6.9, 11.4) is nearly stable from pH 4.5 to 6.0, then increases sharply from pH 6 to 8, and levels off again between pH 8 to 10. These results are similar to those obtained by Greschonig and Schmid [17]. As the plots of electrophoretic mobility versus pH are different for each of the analytes, an optimum pH must be selected for the best separation.…”

Section: Electrophoretic Mobilities Of the Analytes At Varying Phsupporting

confidence: 88%

“…When detection wavelength of 185 nm was applied with the Waters Quanta 4000 instrument, the sensitivity of detection for most of the arsenic species was not increased significantly, whereas the noise was significantly higher than that at 192 nm in the diode-array detector. Higher wavelengths, such as 200 nm reported previously [17] reduced the detection noise significantly and enhanced the LODs of the aryl As compounds, but severely reduced the LODs of the inorganic and methylated species. As a compromise, a wavelength at 192 nm was selected for all experiments unless specified otherwise.…”

Section: Detection Wavelengthmentioning

confidence: 80%

“…CE has been applied to the speciation of arsenic compounds in recent years, but there have been no reports of the separation of all of the target analytes listed in Table 1 [8]. Direct UV detection at 190-200 nm has been applied frequently, with the separation being performed in a phosphate electrolyte at pH 5-9 using an uncoated fused silica capillary and counterelectroosmotic flow (counter-EOF) separation mode [9][10][11][12][13][14][15][16][17]. Alternatively, suppressed or co-EOF modes have also been applied in order to speed up the separation [18][19][20][21][22][23][24][25][26][27][28][29].…”

Section: Introductionmentioning

confidence: 99%

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Separation of organic and inorganic arsenic species by capillary electrophoresis using direct spectrophotometric detection

2002

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Capillary electrophoresis (CE) with UV detection was used for the determination of arsenite, arsenate, monomethylarsonic acid, dimethylarsinic acid, p-aminophenylarsonic acid, 4-hydroxy-3-nitrobenzenearsonic acid, 4-nitrophenylarsonic acid, phenylarsonic acid, and phenylarsine oxide. The electrophoretic mobilities of these anionic species were determined in a 20 mM phosphate buffer in a pH range from 4 to 11, which established pH 10 as the optimum for the separation. The target analytes were then separated in a fused-silica capillary using 20 mM NaHCO(3)-Na(2)CO(3) buffer, pH 10, as electrolyte and detected at 192 nm. Both normal- and reversed electroosmotic flow (EOF) separation modes were investigated and in the latter case, poly(diallydimethylammonium chloride) (PDDAC), was used for dynamic coating of the capillary and to provide a stable and reproducible reversed EOF (relative standard deviation RSD, 0.39%). The influence of electrolyte pH and composition, applied voltage, as well as EOF reversal protocols upon the method performance criteria were investigated. The optimised method provided limits of detection for the target analytes of 1.62, 6.22, 1.45, 1.83, 0.34, 0.40, 0.40, 0.18, and 0.30 mg/L As, respectively. Linearity was obtained in the range of 0.5-40 mg/L As (for aryl compounds) and from 5-100 mg/L As (for the remaining analytes). Reproducibility of peak areas was in the range of 0.8-5.5% RSD. The method was applied to the determination of four aryl arsenic compounds used as additives in animal feed. Analytes were extracted with 40 mM hydrochloric acid - acetonitrile 4:1 v/v, and then cleaned up by passing through a C(18) solid-phase extraction cartridge before analysis by CE with detection at 200 nm. Recoveries for the four analytes were in the range of 78.8-108.3%.

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Section: Electrophoretic Mobilities Of the Analytes At Varying Phsupporting

confidence: 88%

Section: Detection Wavelengthmentioning

confidence: 80%

Section: Introductionmentioning

confidence: 99%

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Separation of organic and inorganic arsenic species by capillary electrophoresis using direct spectrophotometric detection

2002

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“…A baseline separation in a MEKC system with direct UV detection was reported for simultaneous determination of ten arsenic species, including oxoanions, DMA, and 7 other organoarsenic compounds [52]. Studies on spiked urine samples were also carried out.…”

Section: Arsenicmentioning

confidence: 99%

Speciation of oxidation states of elements by capillary electrophoresis

Trojanowicz¹,

Poboży

2003

J of Separation Science

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Speciation of oxidation states of elements by capillary electrophoresisProgress made in the last five years in the application of capillary electrophoresis methods to chemical speciation of elements is reported on the basis of over 100 literature references. The main trends observed include development of new on-and offcapillary derivatization methods, application of new detection methods, and especially coupling of CE separation systems to powerful atomic spectroscopy and mass spectrometry instruments with various ionization techniques, providing either a sensitive element-specific detection method or a third dimension for high performance separation. Besides numerous CZE and MEKC capillary electrophoresis methods only very few examples of CE speciation with capillary electrochromatography can be found. Concerning the chemical forms of elements determined, the new procedures developed are mostly focused on redox speciation of various oxidation states of elements, metal-bound high molecular compounds, and organometallic species.

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“…The determination of several arsenic species in real samples was demonstrated [22][23][24][25][26][27], although preconcentration techniques, such as large-volume injection and field-amplified sample stacking, had to be applied in most cases.…”

mentioning

confidence: 99%

Study of the determination of inorganic arsenic species by CE with capacitively coupled contactless conductivity detection

et al. 2007

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The determination of arsenic(III) and arsenic(V), as inorganic arsenite and arsenate, was investigated by CE with capacitively coupled contactless conductivity detection (CE-C(4)D). It was found necessary to determine the two inorganic arsenic species separately employing two different electrolyte systems. Electrolyte solutions consisting of 50 mM CAPS/2 mM L-arginine (Arg) (pH 9.0) and of 45 mM acetic acid (pH 3.2) were used for arsenic(III) and arsenic(V) determinations, respectively. Detection limits of 0.29 and 0.15 microM were achieved for As(III) and As(V), respectively by using large-volume injection to maximize the sensitivity. The analysis of contaminated well water samples from Vietnam is demonstrated.

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Capillary electrophoretic separation of inorganic and organic arsenic compounds

Cited by 18 publications

References 0 publications

Separation of organic and inorganic arsenic species by capillary electrophoresis using direct spectrophotometric detection

Separation of organic and inorganic arsenic species by capillary electrophoresis using direct spectrophotometric detection

Speciation of oxidation states of elements by capillary electrophoresis

Study of the determination of inorganic arsenic species by CE with capacitively coupled contactless conductivity detection

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