A colorimetric method for the quantitation of uronic acids and a specific assay for galacturonic acid.
A method of quantitating uronic acids and uronic acids from pectin in particular is described. The method uses carbazole in 80% sulfuric acid with borate ions added. The assay is carried out at 60 degrees C. This assay has some cross reactivity with aldose sugars and must be timed precisely. A further method that is specific for galacturonic acid is also described. This method uses concentrated sulfuric acid and carbazole only. Of the biological substances tested, only formaldehyde and glyceraldehyde showed a reactivity of more than 10% that of galacturonic acid on a weight to weight basis.
Taylor
K A
KA
Department of Animal and Poultry Science, University of Guelph, Ontario, Canada.
Buchanan-Smith
J G
JG
D001888:Boric Acids; D003124:Colorimetry / Q000379:methods*; D006603:Hexuronic Acids / Q000032:analysis*; D007700:Kinetics; D010368:Pectins / Q000737:chemistry; D013057:Spectrum Analysis; D013696:Temperature; D014574:Uronic Acids / Q000032:analysis*
D001888:Boric Acids; D006603:Hexuronic Acids; D014574:Uronic Acids; C007819:galacturonic acid; D010368:Pectins; C032688:boric acid