Oxymercuration-demercuration kappa number: An accurate estimation of the lignin content in chemical pulps
2002 (English)In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, Vol. 17, no 4, 410-414 p.Article in journal (Refereed) Published
In the kappa number determination, it has been found that non-lignin structures contribute to the consumption of permanganate, and thus make it difficult to estimate the lignin content in the pulp. In order to improve the accuracy of the determination, a two-step pretreatment with mercury acetate - sodium borohydride prior to a conventional kappa number determination is proposed. It has been found that such a pretreatment eliminates all interfering structures in the pulp except a, P-unsaturated carboxylic acid groups. and thus permits a very accurate estimation of the lignin content. The method has been termed "oxymercuration - demercuration (Ox-Dem) kappa number" and can be used to obtain information not only about the lignin content but also about the quantity of other oxidizable structures present in a chemical pulp. New information concerning the delignification reactions taking place in pulping and bleaching can thus be obtained.
Place, publisher, year, edition, pages
2002. Vol. 17, no 4, 410-414 p.
kappa number, oxymercuration, demercuration, kraft pulps, permanganate consumption, lignin determination, HEXENEURONIC ACID GROUPS, HEXENURONIC ACID, SOFTWOOD, XYLAN
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-12989ISI: 000180616600009OAI: oai:DiVA.org:kth-12989DiVA: diva2:320010
QC 201005212010-05-212010-05-212010-05-21Bibliographically approved