If you wish to measure arabinoxylan, please refer to our K-XYLOSE booklet, sample preparation point (C) Determination of D-xylose in polysaccharides and fibrous plant material, pg.10.

D-Xylose (K-XYLOSE) Data Booklet

To calculate the arabinoxylan content in the sample the percentage D-xylose content of the arabinoxylan must be known.

After the acid hydrolysis step you can measure xylose and by knowing the ratio of arabinose:xylose in the arabinoxylan you can calculate the arabinoxylan content, e.g. wheat flour arabinoxylan contains 62% of D-xylose. 

If you don't know the ratio of arabinose:xylose in your sample you can measure the arabinose content in the sample after the acid hydrolysis using the Megazyme K-ARGA kit linked below: