We are working on a quantification method for mannan and glucan detection by spectrophotometry. Glucan and mannan are separated during the extraction process, however, we cannot calculate its amount. Because it is not possible to draw the calibration curve of glucose and mannose with spectrophotometry. By increasing the concentration of glucose and mannose, their absorption increases irrationally several times. Does anyone have any helpful advice or references to share?

Your help would be greatly appreciated!

Thank you.