Chromatography Forum

Does anyone have a suggestion for cleaning up the extraction solution
from Luffa [a vegetable grown in Asia] in order to eliminate unknown peaks to get a better chromatogram of ascorbic acid. Dithiothreitol was used to convert all DHAA to AA. We have interferring shoulder absorption
peaks on the AA.

The Luffa is macerated and extracted with !% m-HPO3 followed by centrifuging and filtering thru a 0.22 micron filter.

Unleess the material had been dried (or nearly so) there should be no dehydro-Asc in living matter. (I am convinced that statements to the contrary are due to errors in workup, that is, oxidation during workup). Can you assess what the shoulder is? Maybe it is Asc and you just have a mobile phase sample solvent incompatibility. Also, there is a large number of methods for this plant analysis out there, these may help to give you ideas how to modify your analysis.

What column are you using?