|
| << vorige |
Tijdschrift beschrijving
Alle jaargangen van het bijbehorende tijdschrift
Alle afleveringen van het bijbehorende jaargang
Alle artikelen van de bijbehorende aflevering
Details van artikel 8 van 8 gevonden artikelen
| Titel: |
Using 13C-NMR spectroscopy to evaluate the binding mechanism of bound pesticide residues in soils |
| Auteur: |
Wais, A. Burauel, P. de Graaf, A. A. Haider, K. Fuhr, F. |
| Verschenen in: |
Journal of environmental science and health. Part B, Pesticides, food contaminants, and agricultural wastes |
| Paginering: | Jaargang 31 (1996) nr. 1 pagina's 1-24 |
| Jaar: |
1996-01 |
| Inhoud: |
Humic acids (HA) derived from humified, 13C-depleted maize were used for 13C-NMR spectroscopic investigations of bound residues of the fungicide active ingredient anilazine (part 1 of this series, Wais et al., 1995). Due to the lowered 13C-NMR background signals of these HA a comparision to the 13C-NMR spectra of native HA was not possible. Further investigations of HA derived from humified maize with natural carbon abundance became necessary. It was demonstrated that apart from different humification procedures, after a period of 26 weeks the 13C-NMR spectra of the artificially prepared HA were almost identical to native HA samples. A time resolution of the humification indicates that the chemical structure of the model HA more closely resembles the non-humified material or the alkaline extracts of the straw itself during the first 8 weeks of the humification procedure. The GPC chromatograms of the HA resulting from these treatments underline this fact, because of their decrease in molecular weight. The microbial activity detected by DMSO reduction was found to be nearly the same for all humification procedures at the end of the experiment. Native HA of different origin do not show significant differences in their 13C-NMR spectra. A comparision, however, of the model HA or the native HA to commercial HA or to the alkaline extract of the maize straw itself indicates great differences in chemical structure. This indicates that commercial HA do not fulfil the requirements for utilization as model substances for binding or adsorption studies with respect to environmental considerations. |
| Uitgever: |
Taylor & Francis |
| Bronbestand: |
Elektronische Wetenschappelijke Tijdschriften |
Details van artikel 8 van 8 gevonden artikelen
| << vorige |