Application of a novel, plastic formed carbon as a precolumn packing material for the liquid chromatographic determination of acetylcholine and choline in biological samples

A novel carbon material, plastic formed carbon (PFC), was prepared by mixing various amounts of pure graphite with an organic binder and pyrolysing the mixture to ''glassy carbon'' at a modest final temperature of 1000-1400 degrees C. This preparation procedure allows more convenient and precise control of the final graphite adsorption characteristics. Various PFC materials were constructed and tested both as bulk adsorbents and as precolumn packings for the direct determination of ACh and Ch in brain tissue homogenates. The PFC precolumns prepared from 12.5-50% graphite, by mass, were capable of selectively removing interfering species while not adsorbing any of the desired quaternary amine analytes. The usually large solvent front was also dramatically reduced with these precolumns. These PFC precolumns are useful for the direct determination of ACh and Ch in brain tissue homogenates and other biological samples.