Detection of choline and acetylcholine in a pharmaceutical preparation using high-performance liquid chromatography/electrospray ionization mass spectrometry.

A sensitive, rapid, and specific method for the detection of choline and acetylcholine in a pharmaceutical preparation is described. The method employs a perfluorinated carboxylic acid as ion-pairing reagent, post-column addition of a surface tension reducing agent and mass spectrometric detection using either selected ion monitoring (SIM) or selected reaction monitoring (SRM) modes. The resulting chromatographic performance is comparable or superior to methods reported previously in both quality of the separation and sensitivity when using mass spectral detection, with the added advantage of reduced cycle time. Acetylcholine is easily and rapidly separated from its major decomposition product choline. The method was able to detect acetylcholine and its primary degradation product choline at the 30 fmol level, with an analysis time of less than 6 min.