I would prefer a simple qualitative test.How can we test the purity of an extracted cellulose by the use of sodium hydroxide and sodium hypochlorite? For the corresponding synthesized CMC?
You can use the method of alpha cellulose by using 17.5% NaOH and 8.3%NaOH. This method is defined in the book of Rowell, R.M. (2005). Handbook of Wood Chemistry and wood Composites, Taylor & Francis Group, CRC Press, USA
About 3 gram of the air dried pulp sample was placed in aporcelain beaker then 25 ml of 17.5% sodium hydroxide (w/w) were added. After leaving to swell for 4 minutes (time was exactly measured from the last drop of sodium hydroxide) the pulp was pressed with a glass rod for 3 minutes. After pressing, another 25 ml of sodium hydroxide was added and contents were mixed thoroughly reaching a homogeneous past (mixing for about 1 minute). The beaker was then covered and left for 35 minutes at 20 ˚C, then 100 ml's distilled water were added and quickly filtered under suction using a sintered glass funnel. The filtrate was poured on the past twice before washing with distilled water. After washing with distilled water till neutrality, 100 ml of 10% acetic acid was added drop-wise for washing followed by distilled water. The temperature must be kept constant at 20 ˚C during the whole experiment. The alpha-cellulose was estimated gravime-trically after dryness in drying oven at 105-106 ˚C (T203 cm-99).
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