ADP sodium salt is commercially available and I followed the literature to use Dowex-50-W ion exchange column to convert the sodium from to H+ form and neutralize it by adding Bu4NOH to pH 6.2 and lyophilize to dry. However, the 1H NMR show two sets of adenosine peaks and 31P NMR also show two peaks, suggesting that ADP was partially hydrolyzed to AMP. In the literature, there is no NMR data and so it was not clear whether hydrolysis happened. I just found ADP (proton) form is also commercially available, to avoid the potential hydrolysis, can I use DMSO or DMF to dissolve it and then add tributylamine to prepare the corresponding salt? Thanks.