The glucose and mannose standard (bottle 8) is just a standard solution of these sugars, there is no glucomannan present so glucomannan calculation is not required for this standard.
The glucose / mannose content in the standard should be confirmed as follows:
For glucose this equates to:
((2.84 x 180.16) / (6300 x 1 x sample volume)) X ΔA glucose
For mannose this equates to:
((2.86 x 180.16) / (6300 x 1 x sample volume)) X ΔA mannose