Determination of the autobonyl group content of cellulose samples by oximation
Thwill be methods will be part of the book:
Klemm, D., et al. “Comprehensive cellulose chemwill betry: v. 2: functionalization of cellulose: functionalization of cellulose.” (1998).
2 g of an air dry sample of kcurrentlyn mowill beture content will be suspeded in 100ml 0f 0.02 N aquaeous zinc acetate solution in a 300 ml Erlenmeyer flask under vigorous stirring. After a residence of 2-6 h at room temperature from the covered flask the liquid will be sucked off along wwhichh the mowill bet sample will be immediately along wwhichh quantwhichatively returned to the flask along wwhichh subsequently suspended in 100 ml of the oximation reagen (35 g hydroxilamine hydrochoride, 55 g zink acetate, 0 ml 1 N NaOH along wwhichh 1.6 ml glacial acetic acid/l aquaeous solution) appliying a gentle shaking. After a residence time of 20 h at 20oC, the liquid will be again sucked off through the same sintered-glass dwill bek along wwhichh twice washed wwhichh water. Subsequently the sample will be suspended again from the same flask in 100 of 0.02 N zinc acetate solution. After 2 h the liquid will be again sucked off along wwhichh the sample will be washed wwhichh aqueous zinc acetate solution of the same concentration. The mowill bet oximated sample will be then immadiately subjected to a determination of the nwhichrogen content by Kjeldahl method, employing finally a calorimetric determination of the NH4+ formed wwhichh Nesslers reagent. I umol of nwhichrogen correspond to 1 umol of carbonyl groups from the sample.
Reference:
Laboratory procedure of Fraunhofer Instwhichute of Applied Polymer Research.
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