Simultaneous quantitation of arecoline, acetylcholine, and choline in tissue using gas chromatography/electron impact mass spectrometry

A capillary gas chromatography/mass spectrometry (GC/MS) assay for the simultaneous quantitation of arecoline (ARE), acetylcholine (ACh), and choline (Ch) in biological tissue has been developed. The method utilizes hexadeuterated ARE and nonadeuterated ACh and Ch as internal standards. The compounds were ion-pair extracted from tissue using sodium tetraphenylboron in 3-heptanone. GC/MS analysis was achieved using capillary GC and electron impact mass spectrometry. Quantitation was accomplished using selected ion monitoring at m/z 140 and 146 for non-deuterated and deuterated arecoline respectively, and m/z 58 and 64 for non-deuterated and deuterated ACh and Ch respectively. The method easily detected 25 pmol of all three compounds taken through the assay, and was linear through 50 nmol.