Title
Isolation and characterization of lignin from Stipa tenacissima L. and Phoenix dactylifera
Authors
MOHAMED AMMAR RAMZI KHIARI BESMA BERRIMA MOHAMED NACEUR BELGACEM and ELIMAME ELALOUI

Received November 1, 2013
Published Volume 48 Issue 3-4 March-April
Keywords Stipa tenacissima L., Phoenix dactylifera, lignin, NMR, UV spectroscopy

Abstract
This paper is devoted to the isolation of lignin from Stipa tenacissima L. and Phoenix dactylifera by three different processes, namely, CIMV, MILOX and Acetosolv, and its characterization. The Acetosolv process was found to be the most efficient cooking process, as deduced from the combined severity values and the pulp yield. The UV spectroscopy revealed that the lignin obtained from Phoenix dactylifera is more pure than that arising from Stipa tenacissima L. In fact, the latter presents higher amounts of carbohydrate impurities. Also, several techniques were used in order to characterize the obtained lignin from the two raw materials, namely: 13C-NMR and FTIR spectroscopy. Moreover, the chemical study of the structure of lignin isolated from Stipa tenacissima L. demonstrated that it is composed of HGS type and characterized by a high content of syringyl units. Instead, the lignin isolated from Phoenix dactylifera presents a higher content of the guaiacyl units.