HPLC Retention of Obidoxime

Obidoxime, a highly polar compound with two quaternary amines linked by a short hydrophilic chain, poses challenges in reverse-phase chromatography due to poor retention and severe tailing caused by interactions with residual silanols. The Zodiac HST C column resolves these issues by utilizing strong cation-exchange and weak reverse-phase mechanisms. Its carboxylic groups shield residual silanols, improving peak shape for quaternary amines. Retention time can be optimized by adjusting pH and buffer concentration.

This efficient method allows reliable retention and quantitation of obidoxime and similar hydrophilic quaternary amines. Various buffers and detection techniques can ensure purity analysis. Obidoxime, part of the oxime drug family, is crucial for treating nerve gas poisoning by reversing the binding of organophosphorus compounds to acetylcholinesterase.