The cellulose content of pulp refers to the content of all cellulose in pulp, including cellulose, hemicellulose and lignin. There are many methods for determining the cellulose content of pulp, among which the phenol-sulfuric acid method and the heating-acidolysis method are commonly used.
Phenol-sulfuric acid assay:
Sample preparation: Take an appropriate amount of pulp sample, wash it with deionized water, and then dry it to constant weight.
Preparation of dilute phenol solution: Take a certain amount of pure phenol and prepare a 5% phenol solution with deionized water.
Determination process: Weigh a certain amount of dry sample, add a certain amount of 5% phenol solution and sulfuric acid, put it in a Water Bath for hydrolysis, then filter the hydrolyzed solution, wash it, dry it to constant weight, and then weigh it to get The content of cellulose in pulp.
Calculation: The formula for calculating the content of cellulose in pulp is: cellulose content (%) = (dry weight of sample after hydrolysis/dry weight of sample) × 100%.
Heating-acid hydrolysis method:
Sample preparation: Take an appropriate amount of pulp sample, wash it with deionized water, and then dry it to constant weight.
Heating: add the sample into the acid solution, heat to a certain temperature for a certain period of time, so that the cellulose in the pulp is partially degraded into glucose.
Dilution: Dilute the heated solution to an appropriate concentration.
Determination: Determination of glucose content using color reagent and colorimetry.
Calculation: Calculate the content of cellulose in pulp through the content of glucose.
NBCHAO reminds you: the method of determining the cellulose content in pulp requires strict control of heating temperature, time and other conditions to avoid measurement errors caused by excessive pyrolysis of the sample. At the same time, it is also necessary to pay attention to the details of sample preparation and operation process to ensure the accuracy of the experimental results.
