EQUILIBRIUM BETWEEN FREE AND BOUND LIPIDS IN A RENDZINA SOIL IN NATURAL CONDITIONS AND WITH LABORATORY DISTURBANCES

André Amblès (1) , Laurent Lemée (1) , Pierre Jambu (2) , Pierre Mayoungou-Vembet (1)

1 SRSN - Synthèse et réactivité des substances naturelles
2 Laboratoire de Pédologie (URA721) Chimie des Produits Naturels et de l'Environnement

The Ap horizon of a rendzina soil was sampled sieved and incubated directly (control) or after supplementation with a C20 n-alkane (eicosane), after extraction of free lipids. An eight-week incubation was conducted after which free and bound lipids were extracted. Each fraction was fractioned into different families by liquid chromatography. The n-alkanes were separated and identified by GC and GC-MS. In the control an equilibrium between the free and the bound n-alkanes was established. After extraction of free lipids, the equilibrium was restored by desorption of bound n-alkanes, during incubation. The addition of eicosane to the free phase induced an additional bonding of natural n-alkanes and their transformation into alcohols or acids by a cooxidation process. The addition of eicosane after extraction of the free lipids inhibited the desorption of the bound n-alkanes and activated their decomposition.

Domaines: Géochimie

André Amblès, Laurent Lemée, Pierre Jambu, Pierre Mayoungou-Vembet. EQUILIBRIUM BETWEEN FREE AND BOUND LIPIDS IN A RENDZINA SOIL IN NATURAL CONDITIONS AND WITH LABORATORY DISTURBANCES. Agrochimica, 1997, 41 (5), pp.196-208. ⟨hal-00160396⟩