Accurate Quantifcation of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by 13C Solid-State Nuclear Magnetic Resonance.
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| Title: | Accurate Quantifcation of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by 13C Solid-State Nuclear Magnetic Resonance. |
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| Authors: | Mao, J.-d.1, Schmidt-rohr, K.1 srohr@iastate.edu. |
| Source: | Environmental Science & Technology. 5/1/2004, Vol. 38 Issue 9, p2680-2684. 5p. |
| Subjects: | Aromatic compounds, Carbon, Organic compounds, Nuclear magnetic resonance, Polarization (Nuclear physics), Anisotropy, Humic acid |
| Abstract: | An improved approach for accurately determining the aromatic carbon fraction (fa) and nonprotonated aromatic carbon fraction (faN) in natural organic matter by solid- state 13C NMR is described. Quantitative peak areas are obtained from direct polarization 13C nuclear magnetic resonance (NMR) under high-speed magic angle spinning (MAS). The problem of overlap between aromatic and alkyl carbon resonances around 90-120 ppm in 13C NMR spectra is solved by a 13C chemical shift anisotropy (CSA) filter technique. After correction for residual spinning sidebands, an accurate value of the aromaticity fa is obtained. To obtain a quantitative faN fraction, dipolar dephasing was adapted for high-speed MAS 13C NMR; the separation of the signals of nonprotonated alkyl and aromatic carbons was achieved by CSA filtering plus dipolar dephasing. The method is demonstrated on a peat humic acid, yielding fa = 45 ± 2% and faN = (0.64 ± 0.07) x 45%. [ABSTRACT FROM AUTHOR] |
| Copyright of Environmental Science & Technology is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 13111176 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Accurate Quantifcation of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by <superscript>13</superscript>C Solid-State Nuclear Magnetic Resonance. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Mao%2C+J%2E-d%2E%22">Mao, J.-d.</searchLink><relatesTo>1</relatesTo><br /><searchLink fieldCode="AR" term="%22Schmidt-rohr%2C+K%2E%22">Schmidt-rohr, K.</searchLink><relatesTo>1</relatesTo><i> srohr@iastate.edu.</i> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Environmental+Science+%26+Technology%22">Environmental Science & Technology</searchLink>. 5/1/2004, Vol. 38 Issue 9, p2680-2684. 5p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Aromatic+compounds%22">Aromatic compounds</searchLink><br /><searchLink fieldCode="DE" term="%22Carbon%22">Carbon</searchLink><br /><searchLink fieldCode="DE" term="%22Organic+compounds%22">Organic compounds</searchLink><br /><searchLink fieldCode="DE" term="%22Nuclear+magnetic+resonance%22">Nuclear magnetic resonance</searchLink><br /><searchLink fieldCode="DE" term="%22Polarization+%28Nuclear+physics%29%22">Polarization (Nuclear physics)</searchLink><br /><searchLink fieldCode="DE" term="%22Anisotropy%22">Anisotropy</searchLink><br /><searchLink fieldCode="DE" term="%22Humic+acid%22">Humic acid</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: An improved approach for accurately determining the aromatic carbon fraction (fa) and nonprotonated aromatic carbon fraction (faN) in natural organic matter by solid- state 13C NMR is described. Quantitative peak areas are obtained from direct polarization 13C nuclear magnetic resonance (NMR) under high-speed magic angle spinning (MAS). The problem of overlap between aromatic and alkyl carbon resonances around 90-120 ppm in 13C NMR spectra is solved by a 13C chemical shift anisotropy (CSA) filter technique. After correction for residual spinning sidebands, an accurate value of the aromaticity fa is obtained. To obtain a quantitative faN fraction, dipolar dephasing was adapted for high-speed MAS 13C NMR; the separation of the signals of nonprotonated alkyl and aromatic carbons was achieved by CSA filtering plus dipolar dephasing. The method is demonstrated on a peat humic acid, yielding fa = 45 ± 2% and faN = (0.64 ± 0.07) x 45%. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Environmental Science & Technology is the property of American Chemical Society and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1021/es034770x Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 5 StartPage: 2680 Subjects: – SubjectFull: Aromatic compounds Type: general – SubjectFull: Carbon Type: general – SubjectFull: Organic compounds Type: general – SubjectFull: Nuclear magnetic resonance Type: general – SubjectFull: Polarization (Nuclear physics) Type: general – SubjectFull: Anisotropy Type: general – SubjectFull: Humic acid Type: general Titles: – TitleFull: Accurate Quantifcation of Aromaticity and Nonprotonated Aromatic Carbon Fraction in Natural Organic Matter by 13C Solid-State Nuclear Magnetic Resonance. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Mao, J.-d. – PersonEntity: Name: NameFull: Schmidt-rohr, K. IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 05 Text: 5/1/2004 Type: published Y: 2004 Identifiers: – Type: issn-print Value: 0013936X Numbering: – Type: volume Value: 38 – Type: issue Value: 9 Titles: – TitleFull: Environmental Science & Technology Type: main |
| ResultId | 1 |
