“…The compound can be crystallized easily from water, with which activated charcoal is useful. In addition, chemical purity of the product, if desired, can be established by nonaqueous titration (19,20) or by thin-layer (20,21) and paper chromatography (20). Chromatographic methods can also be used to separate mixtures of 2-alkylbenzimidazoles arising in analysis of materials containing more than one acyl moiety, such as cellulose acetate butyrate.…”