Quantification of Pentose Content via Furfural Production

By heating the pulp with 12% hydrochloric acid, the polysaccharide in the pulp (α-cellulose) was converted to furfural.
The content of pentose was obtained from the empirical formula by calculating the amount of furfural. The formulae for both are given below: $$X_1=\frac{(V_1-V_2)\times A\times c\times 500}{200m}\times 100$$
X₁—Content of furfural, %;
X₂—Content of pentose, %;
1.375—Conversion of furfural to pentose;
A—The amount of furfural equivalent to 1 mL 1 mol/L sodium thiosulfate standard solution, A (Tetrabromination) = 0.024;
V₁—Consumption of standard sodium thiosulfate solution during blank test, mL;
V₂—Consumption of standard sodium thiosulfate solution for titrating samples, mL;
c—Concentration of sodium thiosulfate standard solution, mol/L;
m—Quality of dry test sample, g.