Effect of residual vanadyl ions on the spectroscopic analysis of humic acids: a multivariate approach.

dc.contributorETELVINO HENRIQUE NOVOTNY, CNPS; H. Knicker, Lehrstuhl fur Bodenkunde, Technische Universitat Munchen; LADISLAU MARTIN NETO, DE/P&D; R. B. V. AZEREDO, UFF; M. H. B. HAYES, Chemical and Environmental Sciences University of Limerick.
dc.creatorNOVOTNY, E. H.
dc.creatorKNICKER, H.
dc.creatorMARTIN NETO, L.
dc.creatorAZEREDO, R. B. V.
dc.creatorHAYES, M. H. B.
dc.date2016-10-05T22:35:53Z
dc.date2016-10-05T22:35:53Z
dc.date2008
dc.date2008-12-09
dc.date.accessioned2017-03-06T23:09:40Z
dc.date.available2017-03-06T23:09:40Z
dc.identifier13577
dc.identifierhttp://www.alice.cnptia.embrapa.br/handle/doc/339740
dc.identifier10.1111/j.1365-2389.2007.00983.x
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/336899
dc.descriptionIn a study of the vanadyl (VO2þ)-humic acids system, the residual vanadyl ion suppressed fluorescence and specific electron paramagnetic resonance (EPR) and NMR signals. In the case of NMR, the proton rotating frame relaxation times (T1qH) indicate that this suppression is due to an inefficient H-C cross polarization, which is a consequence of a shortening of T1qH. Principal components analysis (PCA) facilitated the isolation of the effect of the VO2þ ion and indicated that the organic free radical signal was due to at least two paramagnetic centres and that the VO2þ ion preferentially suppressed the species whose electronic density is delocalized over O atoms (greater g-factor). additionally, the newly obtained variables (principal components ? PC) indicated that, as the result of the more intense tillage a relative increase occurred in the accumulation of: (i) recalcitrant structures; (ii) lignin and long-chain alkyl structures; and (iii) organic free radicals with smaller g-factors.
dc.description2008
dc.languageen
dc.publisherEuropean Journal of Soil Science, Oxford, v. 59, n. 3, p. 439-444, Jun. 2008.
dc.relationEmbrapa Solos - Artigo em periódico indexado (ALICE)
dc.subjectAnálise espectroscópica
dc.subjectÁcidos húmicos
dc.titleEffect of residual vanadyl ions on the spectroscopic analysis of humic acids: a multivariate approach.
dc.typeArtículos de revistas


Este ítem pertenece a la siguiente institución