Physicochemical characterization of edible clays and release of trace elements

Odilon Kikouama (1) , Léon Konan Koffi (2) , A. Katty (3) , Jean-Pierre Bonnet (4)

1 Groupe Matériaux et Santé
2 Laboratoire de Chimie des Matériaux Inorganiques
3 CMTR - Chimie métallurgique des terres rares
4 GEMH - Groupe d'Etudes des Matériaux Hétérogènes

The mineralogical composition of seven edible clays from West Africa (Ivory Coast, Guinea and Senegal) was determined by X-ray diffraction, thermal (DTA, TGA and DSC) and chemical (ICP-MS and ICP-OES) analyses and measurement of specific surface areas and density. The major compounds were kaolinite, illite, muscovite, quartz and feldspars. Electrochemical analysis of clay suspensions by voltamperometry (SnO2:F) yielded no results at 6.5 < pH < 7 and pH ≈ 8.3. However, ionic species transfer was revealed at pH ≈ 1.8 by an anodic peak. The analysis by X-ray diffraction of the metal cation layers which were deposited on the blades (SnO2:F), showed the presence of mineral elements having therapeutic implications such as Fe and Zn.

Mots clés: Edible clays; Mineralogical composition; Voltamperometry; Release of trace elements

Domaines: Matériaux

Odilon Kikouama, Léon Konan Koffi, A. Katty, Jean-Pierre Bonnet. Physicochemical characterization of edible clays and release of trace elements. Applied Clay Science, 2009, 43 (1), pp.135-141. ⟨10.1016/j.clay.2008.07.031⟩. ⟨hal-00630545⟩