I would like to perform some NMR and LC-MS analyses with a polar extract in glycerol and water but I need to get rid of the glycerol first, does anyone knows a good method?
Maybe you could consider repeated washing (liquid-liquid extraction) with tert-amyl alcohol, to extract most of the glycerol from the aqueous phase. Separation could be further enhanced by salting-out (e.g. adding NaCl).
The ternary phase diagram (with tie lines) for the glycerol―water―tert-amyl alcohol can be found at: Alfred W. Francis, "Liquid-Liquid Equilibriums", Interscience Publishers (John Wiley & Sons), New York and London, 1963, p. 36.