Evidently, higher [Me2Al(THF)2] + content is correlated with the increased intensity of higher m/z anions in these mixtures. We wondered whether this is due to higher total concentrations of the different ion precursors present and/or higher average MW and thus reactivity of the MAO in question. One would anticipate the latter result based on other studies22 while as previously mentioned ESI-MS signal intensity is not directly proportional to solution concentrations, though the anion distributions of the two formulations are clearly different. We thus decided to investigate whether PGSE NMR could distinguish between MAO with different compositions as measured by ESI-MS and also study the effect of solvent polarity on MAO or the ion-pairs derived from it since earlier PGSE NMR work was conducted in low dielectric constant media.