MOLECULAR WEIGHT AND SHAPE OF HUMIC ACID FROM SEDIMENTATION AND DIFFUSION MEASUREMENTS ON FRACTIONATED EXTRACTS
書誌事項
- 公開日
- 1972-12
- 権利情報
-
- http://onlinelibrary.wiley.com/termsAndConditions#vor
- DOI
-
- 10.1111/j.1365-2389.1972.tb01670.x
- 公開者
- Wiley
この論文をさがす
説明
<jats:title>Summary</jats:title> <jats:p>Whole humic acid extracts are usually too polydisperse for reliable molecular‐weight measurement to be made in the ultracentrifuge by the sedimentation velocity technique. Consequently, the humic acid used in this study was fractionated with respect to molecular weight into fractions of low polydispersity by extensive use of gel‐permeation chromatography and other fractionation techniques.</jats:p> <jats:p> The sedimentation and diffusion coefficients of the fractions were determined and molecular‐weight values calculated. These values ranged approximately from 2 × 10 <jats:sup>3</jats:sup> to 1.5 × 10 <jats:sup>6</jats:sup> , the higher figure not necessarily representing the upper limit for these substances. </jats:p> <jats:p>On the basis of the frictional parameters calculated from the experimental data, it is proposed that the molecule adopts the solution conformation of a randomly coiled polymer in which branching may be significant, particularly at higher molecular weights.</jats:p>
収録刊行物
-
- Journal of Soil Science
-
Journal of Soil Science 23 (4), 394-408, 1972-12
Wiley