Zeolites are important heterogeneous acid catalysts with pores the diameter of small molecules. Turning zeolites into bases would open up these unique materials to alkaline-catalyzed reactions, many of which are important in the synthesis of liquid fuels from biomass. One method of preparing alkaline zeolites is to replace some framework oxygen with nitrogen, producing an amine. Unfortunately, such replacements require a post-synthetic treatment, so the question of whether the resulting materials are intact is still open. It is, in general, difficult to characterize these new materials experimentally (since the actual structures can only be guessed), so we employ a mixture of experiment and theory to develop characterization methods suitable for nitrogen-substituted zeolites. We confirm the observation that high-temperature treatment produces new peaks in the silicon NMR spectrum, and present calculations suggesting that these new peaks correspond to framework substitutions. This suggests the possibility of using a zeolitic catalyst in base-catalyzed reactions.