8 research outputs found
Conservation de la semence congelée de verrat. Résultats in vitro et après insémination.
No full textNational audienc
Analyse de facteurs de variation de la production spermatique de verrats d'insémination artificielle
No full textNational audienc
Fast, Easy, and Economical Quantification of Lignin Phenolic Hydroxyl Groups: Comparison with Classical Techniques
No full textThe quantification
of lignin functional groups constitutes an essential
step for effective assessment of lignin transformation. A new, fast,
economical, and simple method without the use of harmful solvents
is presented for lignin phenolic hydroxyl group quantification. The
new method is based on simultaneous conductometric and acid–base
titration based on pH in aqueous medium, and it provides, in a single
measurement, phenolic hydroxyl and carboxyl group quantification.
The new method provokes an inherent error due to the phenolic structure
of lignin. This error should be 10% maximum for the low amount of
condensed structures in the analyzed technical lignin samples. Four
industrial lignin samples (PB-Protobind lignin, ORG-Organolsolv lignin,
KF-Kraft lignin, IND-Indulin lignin) have been analyzed using the
new method, and the results were compared with six classical methods
(UV, <sup>31</sup>P NMR, <sup>1</sup>H NMR, <sup>13</sup>C NMR, Folin
Ciocalteu, and aminolysis). The results showed good statistical correlation
of the new method with the UV and <sup>31</sup>P NMR, the most significant
methods, with coefficients of variation among 6 and 14%. Moreover,
the carboxyl content results presented high accuracy with a traditional
method as tetra-<i>n</i>-butylammonium hydroxide (TnBAH)
potentiometric titration
