1 Scope
This standard specifies the determination method of pentosan content of pulp board for viscose fiber.
This standard is applicable to all kinds of pulp board for viscose fiber.
2 Normative references
The following standards contain provisions which, through reference in this standard, constitute provisions of this standard. At the time of publication, all the editions listed are valid. All standards are subject to revision, and all parties using this standard are encouraged to investigate the possibility of applying the latest editions of the following standards.
GB/T 8170-1987 Rules for rounding off of numberical values
FZ/T 50010.1-1998 Pulp board for viscose fiber - Sampling method
FZ/T 50010.2-1998 Pulp board for viscose fiber - Determination of moisture content
3 Principle
Viscose fiber wood pulp board is heated together with 12% hydrochloric acid to convert pentosan in wood pulp board into furfural. The distilled furfural is determined by volumetric method, and then the pentosan content is calculated.
4 Reagents
Only analytical reagents and distilled water or deionized water are used in analysis.
4.1 12% hydrochloric acid -- 307mL of hydrochloric acid (density: 1.19g/mL) is weighed and added into water for dilution to 1000mL. Acid or water is added. The density of hydrochloric acid is 1.057g/mL when the temperature is adjusted to 20℃;
4.2 Mixed solution of sodium bromide and sodium bromate -- 2.5g of sodium bromate and 12g of sodium bromide (or 2.8g of potassium bromate and 15g of potassium bromide) are weighed for dissolution in water and transferred into a 1000mL volumetric flask for dilution to scale with water;
4.3 Sodium thiosulfate standard solution: c(Na2S2O3)=0.1mol/L;
4.4 10% potassium iodide solution: 10g of potassium iodide is dissolved in 100mL of water;
4.5 Aniline acetate solution: 1mL of newly distilled aniline is weighed into a small beaker, 9mL of glacial acetic acid is added and stirred well;
4.6 1mol/L sodium hydroxide solution: 2g of sodium hydroxide is weighed and dissolved in a 50mL volumetric flask for dilution to 100mL;
4.7 0.5% starch solution: 0.5g soluble starch is weighed and dissolved in 100mL water. It is boiled and cooled for later use;
4.8 0.1% phenolphthalein indicator: 0.1g of phenolphthalein is weighed and dissolved in 100ml of ethanol (50%);
4.9 Sodium chloride
Foreword i
1 Scope
2 Normative references
3 Principle
4 Reagents
5 Apparatus
6 Sample preparation
7 Test procedure
8 Result calculation
9 Precision and allowable error
10 Test report
