An improved methodology for the quantification of uronic acid units in xylans and other polysaccharides.
Uronic acids can be quantified either by a colorimetric determination after treatment with concentrated sulfuric acid and carbazole or by gas chromatography after methanolysis and subsequent acetylation. Both methods suffer from incomplete hydrolysis, an unavoidable degradation of the products to be analysed, and an inability to separate and quantify different types of uronic acids. In the present work, the fundamental chemistry involved in the two methods has been evaluated, and some modifications to increase their accuracy are suggested. By combining the two methods, a complete quantification of all individual types of uronic acids present in a sample can be achieved.
Li
Jiebing
J
Division of Wood Chemistry and Pulp Technology, Department of Fibre and Polymer Technology, Royal Institute of Technology, KTH, SE-100 44 Stockholm, Sweden. jbing@kth.se
Kisara
Koki
K
Danielsson
Sverker
S
Lindström
Mikael E
ME
Gellerstedt
Göran
G
D029662:Betula / Q000737:chemistry; D002227:Carbazoles; D020723:Glucuronic Acid / Q000737:chemistry; D006603:Hexuronic Acids / Q000032:analysis / Q000737:chemistry; D006868:Hydrolysis; D013464:Sulfuric Acids; D014574:Uronic Acids / Q000032:analysis* / Q000737:chemistry*; D014934:Wood / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry*
D002227:Carbazoles; D006603:Hexuronic Acids; D013464:Sulfuric Acids; D014574:Uronic Acids; D014990:Xylans; C095263:hexenuronic acid; C041514:carbazole; C007819:galacturonic acid; D020723:Glucuronic Acid; C033158:sulfuric acid