Photo-Oxidation of Nitrite to Nitrate

Dhar, N. R.; Tandon, S. N.; Biswas, N. N.; Bhateacharya, A. K.

doi:10.1038/133213b0

Cited by 6 publications

(6 citation statements)

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“…In this vein, the nitration of an aromatic compound was first proposed for the conversion of nitrate into nitro-arenes [13]. This approach requires a strongly acidic reaction medium which can cause the unwanted conversion of nitrite to nitrate [14][15]. A modern alternative to nitration is alkylation with pentafluorobenzyl bromide (F 5 BzBr).…”

Section: Introductionmentioning

confidence: 99%

High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate

Meija

Mester

2014

Analytica Chimica Acta

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate Pagliano, E.; Meija, J.; Mester, Z.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=fr L'accès à ce site Web et l'utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D'UTILISER CE SITE WEB. NRC Publications Record / Notice d'Archives des publications de CNRC:http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21272651&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=21272651&lang=fr READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE.http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1016/j.aca.2014.03.018Analytica Chimica Acta, 824, pp. 36-41, 2014 experimental design which generates results with low uncertainties and obviates the need for direct (separate) evaluation of the procedural blank. Nitrite and nitrate detection was achieved using a headspace GCMS procedure based on single-step aqueous derivatization with triethyloxonium tetrafluoroborate at room temperature. In this paper the sample preparation was revised and fundamental aspects of this chemistry are presented. The proposed method has detection limits in the low parts-per-billion for both analytes, is reliable, precise, and has been validated using a seawater certified reference material (MOOS-2). Simplicity of the experimental design, low detection limits, and the use of quadruple isotope dilution makes the present method superior to the state-of-the-art for determination of nitrite and nitrate, and an ideal candidate for reference measurements of these analytes in seawater.

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Section: Introductionmentioning

confidence: 99%

High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate

Meija

Mester

2014

Analytica Chimica Acta

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“…The reaction of the nitrous acid with dissolved oxygen results in the production of nitrate. 5,6 In order to avoid this effect, alkylation was conducted in an alkaline medium (pH = 10) promoted by the pretreatment of the samples with NH 4 OH solution. In this alkaline environment, significant oxidation of nitrite only occurred at high concentrations of nitrite.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

“…The nitration of aromatic compounds has been used to convert nitrate (3) . This approach, however, does not work for nitrite and requires the use of strong acid conditions which may be critical if any nitrite is present because of its possible conversion to nitrate (5)(6) . Another technique used with GC-MS entails alkylation with pentafluorobenzyl bromide (F 5 BzBr) (7) to convert nitrite and nitrate to F 5 Bz-NO 2 and F 5 Bz-ONO 2 , respectively.…”

Section: Introductionmentioning

confidence: 99%

“…Nitrite and nitrate are nonvolatile anions, and their determination by GC/MS can be achieved by derivatization in order to generate volatile species, for example, nitration of aromatic compounds has been used for this purpose . This approach, however, does not work for nitrite and requires the use of strong acid conditions which may be critical if any nitrite is present because of its possible conversion to nitrate. , Another technique used with GC/MS entails alkylation with pentafluorobenzyl bromide (F 5 BzBr) to convert nitrite and nitrate to F 5 Bz–NO 2 and F 5 Bz–ONO 2 , respectively. The pentafluorobenzyl derivatives are suitable for negative chemical ionization (CI−) GC/MS, but they are not employed for static headspace analysis at room temperature due to their low volatility.…”

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Negative Chemical Ionization GC/MS Determination of Nitrite and Nitrate in Seawater Using Exact Matching Double Spike Isotope Dilution and Derivatization with Triethyloxonium Tetrafluoroborate

et al. 2012

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Access and use of this website and the material on it are subject to the Terms and Conditions set forth at Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n'arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. Questions? Contact the NRC Publications Archive team atPublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information. NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://doi.org/10.1021/ac2030128Analytical Chemistry, 84, 5, pp. 2592-2596, 2012-03-06 A BACBD EF D A ABSTRACTThe alkylation of nitrite and nitrate by triethyloxonium tetrafluoroborate allows determination of their ethyl esters by headspace GC-MS. In the present study, significant improvement in analytical performance are achieved by using negative chemical ionization (CI-). Detection limits are improved for at least an order of magnitude than those achieved using electron impact ionization (EI). The derivatization procedure has been optimized and alkaline conditions are adopted to minimize the conversion of nitrite to nitrate (determined to be 0.07% at 100 mg/L NO 2 -) and to avoid the exchange of oxygen between the analytes and the solvent (water).Quantitation entails the use of isotopically enriched standards (N 18 O 2 -and 15 NO 3 -), which also permits monitoring of potential conversion from nitrite to nitrate during the analysis (double spike isotope dilution).

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“…Upon absorption of a photon with an energy E = h ν greater than or equal to the band-gap energy ( E BG ) of the semiconductor (e.g., TiO 2 ), an electron is excited from the valence band into the conduction band, generating a positively charged hole in the valence band (h vb + ). Photocatalytic nitrate reduction was first documented in the 1930s in India, − but its material science fundamentals were not explored until 1987, when Pt-loaded TiO 2 irradiated with UV light showed better nitrate reduction than Pd- or Ru-loaded TiO 2 (TiO 2 alone resulted in little nitrate removal and formed nitrite byproduct). No nitrate removal was observed without a hole scavenger (methanol); minimal nitrate reduction occurs when the recombination rate within the catalyst exceeds that of electron transfer to the adsorbate (i.e., nitrate) (Figure ).…”

Section: Photocatalytic Nitrate Reductionmentioning

confidence: 99%

Catalytic Converters for Water Treatment

et al. 2019

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Fresh water demand is driven by human consumption, agricultural irrigation, and industrial usage and continues to increase along with the global population. Improved methods to inexpensively and sustainably clean water unfit for human consumption are desired, particularly at remote or rural locations. Heterogeneous catalysts offer the opportunity to directly convert toxic molecules in water to nontoxic products. Heterogeneous catalytic reaction processes may bring to mind large-scale industrial production of chemicals, but they can also be used at the small scale, like catalytic converters used in cars to break down gaseous pollutants from fuel combustion. Catalytic processes may be a competitive alternative to conventional water treatment technologies. They have much faster kinetics and are less operationally sensitive than current bioremediation-based methods. Unlike other conventional water treatment technologies (i.e., ion exchange, reverse osmosis, activated carbon filtration), they do not transfer contaminants into separate, more concentrated waste streams. In this Account, we review our efforts on the development of heterogeneous catalysts as advanced reduction technologies to treat toxic water contaminants such as chlorinated organics and nitrates. Fundamental understanding of the underlying chemistry of catalytic materials can inform the design of superior catalytic materials. We discuss the impact of the catalytic structure (i.e., the arrangement of metal atoms on the catalyst surface) on the catalyst activity and selectivity for these aqueous reactions. To explore these aspects, we used model metal-on-metal nanoparticle catalysts along with state-of-the-art in situ spectroscopic techniques and density functional theory calculations to deduce the catalyst surface structure and how it affects the reaction pathways and hence the activity and selectivity. We also discuss recent developments in photocatalysis and electrocatalysis for the treatment of nitrates, touching on fundamentals and surface reaction mechanisms. Finally, we note that despite over 20 years of growing research into heterogeneous catalytic systems for water contaminants, only a few pilot-scale studies have been conducted, with no large-scale implementation to date. We conceive of modular, on-or off-grid catalytic units that treat drinking water at the household tap, at a community well, or for larger-scale reuse of agricultural runoff. We discuss how these may be enhanced by combination with photocatalytic or electrocatalytic processes and how these reductive catalytic modules (catalytic converters for water) can be coupled with other modules for the removal of potential water contaminants.

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Photo-Oxidation of Nitrite to Nitrate

Cited by 6 publications

References 8 publications

High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate

High-precision quadruple isotope dilution method for simultaneous determination of nitrite and nitrate in seawater by GCMS after derivatization with triethyloxonium tetrafluoroborate

Negative Chemical Ionization GC/MS Determination of Nitrite and Nitrate in Seawater Using Exact Matching Double Spike Isotope Dilution and Derivatization with Triethyloxonium Tetrafluoroborate

Catalytic Converters for Water Treatment

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