Hi. I am extracting metabolites from Helicobacter pylori. I have grown the H. pylori strains in BHI broth supplemented with B—cyclodextrin. After that, I centrifuged the bacterial suspension and perform metabolite extraction on both bacterial pellet and supernatant. I’ve used the cold methanol method to extract metabolites from the supernatant. However, after vacuum-evaporate the sample using a Labconco Refrigerated Centrivap concentrator, the sample produces a very dark brownish pellet (which I assumed because of the broth I used to grow the h. Pylori strains). Any suggestion on how to eliminate the color of the pellet as I was told that they could not inject anything with colour into the LC/MS. Thank you!