Acid-soluble lignin is a common pulp component, and its content can be determined by acid hydrolysis-colorimetry or effective liquid chromatography.
Acid hydrolysis-colorimetric method steps are as follows:
Sample preparation: Take an appropriate amount of pulp sample, wash it with deionized water, and then dry it to constant weight.
Acid addition: Add the dry sample to a certain amount of acid (usually concentrated sulfuric acid or hydrochloric acid), and heat it for a certain period of time to carry out acidolysis.
Dilution: Dilute the solution after acid hydrolysis to a certain concentration.
Colorimetry: Mix the diluted solution with a color developer (usually 4-aminobenzenesulfonic acid), and measure the absorbance with a UV-visible Spectrophotometer after a certain period of time.
Calculation: Calculate the content of acid-soluble lignin according to the absorption characteristics of the colorimetric reagent and the absorbance of the control sample.
The effective liquid chromatography steps are as follows:
Sample preparation: Take an appropriate amount of pulp sample, wash it with deionized water, and then dry it to constant weight.
Extraction: Add the sample to an appropriate amount of solvent for extraction (usually 80% methanol or ethanol), heat for a certain period of time, and then filter.
Filtration: Filter the extracted liquid through a 0.45 micron filter to obtain the sample liquid to be tested.
Analysis: Inject the sample solution into an effective liquid chromatograph for analysis to detect the lignin content.
NBCHAO reminds you: In actual operation, it is necessary to strictly control the sample preparation and operation process, as well as the adjustment of instrument conditions, in order to ensure the accuracy and reliability of the experimental results.
