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Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection

[Image: see text] The common selenium oxoanions selenite (SeO(3)(2–)) and selenate (SeO(4)(2–)) are toxic at intake levels slightly below 1 mg day(–1). These anions are currently monitored by a variety of traditional analytical techniques that are time-consuming, expensive, require large sample volu...

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Autores principales: Noblitt, Scott D., Staicu, Lucian C., Ackerson, Christopher J., Henry, Charles S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139182/
https://www.ncbi.nlm.nih.gov/pubmed/25033231
http://dx.doi.org/10.1021/ac502013k
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author Noblitt, Scott D.
Staicu, Lucian C.
Ackerson, Christopher J.
Henry, Charles S.
author_facet Noblitt, Scott D.
Staicu, Lucian C.
Ackerson, Christopher J.
Henry, Charles S.
author_sort Noblitt, Scott D.
collection PubMed
description [Image: see text] The common selenium oxoanions selenite (SeO(3)(2–)) and selenate (SeO(4)(2–)) are toxic at intake levels slightly below 1 mg day(–1). These anions are currently monitored by a variety of traditional analytical techniques that are time-consuming, expensive, require large sample volumes, and/or lack portability. To address the need for a fast and inexpensive analysis of selenium oxoanions, we present the first microchip capillary zone electrophoresis (MCE) separation targeting these species in the presence of chloride, sulfate, nitrate, nitrite, chlorate, sulfamate, methanesulfonate, and fluoride, which can be simultaneously monitored. The chemistry was designed to give high selectivity in nonideal matrices. Interference from common weak acids is avoided by operating near pH 4. Separation resolution from chloride was enhanced to improve tolerance of high-salinity matrices. As a result, selenate can be quantified in the presence of up to 1.5 mM NaCl, and selenite analysis is even more robust against chloride. Using contact conductivity detection, detection limits for samples with conductivity equal to the background electrolyte are 53 nM (4.2 ppb Se) and 380 nM (30 ppb) for selenate and selenite, respectively. Analysis time, including injection, is ∼2 min. The MCE method was validated against ion chromatography (IC) using spiked samples of dilute BBL broth and slightly outperformed the IC in accuracy while requiring <10% of the analysis time. The applicability of the technique to real samples was shown by monitoring the consumption of selenite by bacteria incubated in LB broth.
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spelling pubmed-41391822015-07-17 Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection Noblitt, Scott D. Staicu, Lucian C. Ackerson, Christopher J. Henry, Charles S. Anal Chem [Image: see text] The common selenium oxoanions selenite (SeO(3)(2–)) and selenate (SeO(4)(2–)) are toxic at intake levels slightly below 1 mg day(–1). These anions are currently monitored by a variety of traditional analytical techniques that are time-consuming, expensive, require large sample volumes, and/or lack portability. To address the need for a fast and inexpensive analysis of selenium oxoanions, we present the first microchip capillary zone electrophoresis (MCE) separation targeting these species in the presence of chloride, sulfate, nitrate, nitrite, chlorate, sulfamate, methanesulfonate, and fluoride, which can be simultaneously monitored. The chemistry was designed to give high selectivity in nonideal matrices. Interference from common weak acids is avoided by operating near pH 4. Separation resolution from chloride was enhanced to improve tolerance of high-salinity matrices. As a result, selenate can be quantified in the presence of up to 1.5 mM NaCl, and selenite analysis is even more robust against chloride. Using contact conductivity detection, detection limits for samples with conductivity equal to the background electrolyte are 53 nM (4.2 ppb Se) and 380 nM (30 ppb) for selenate and selenite, respectively. Analysis time, including injection, is ∼2 min. The MCE method was validated against ion chromatography (IC) using spiked samples of dilute BBL broth and slightly outperformed the IC in accuracy while requiring <10% of the analysis time. The applicability of the technique to real samples was shown by monitoring the consumption of selenite by bacteria incubated in LB broth. American Chemical Society 2014-07-17 2014-08-19 /pmc/articles/PMC4139182/ /pubmed/25033231 http://dx.doi.org/10.1021/ac502013k Text en Copyright © 2014 American Chemical Society Terms of Use (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html)
spellingShingle Noblitt, Scott D.
Staicu, Lucian C.
Ackerson, Christopher J.
Henry, Charles S.
Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title_full Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title_fullStr Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title_full_unstemmed Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title_short Sensitive, Selective Analysis of Selenium Oxoanions Using Microchip Electrophoresis with Contact Conductivity Detection
title_sort sensitive, selective analysis of selenium oxoanions using microchip electrophoresis with contact conductivity detection
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4139182/
https://www.ncbi.nlm.nih.gov/pubmed/25033231
http://dx.doi.org/10.1021/ac502013k
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