“…Injection of high doses of 2-(o-cresyl)-4H-1,2,3-benzodioxaphosphoran-2-one into chickens causes ataxia and demyelination of nerves in the spinal cord which are typical symptoms of organophosphate-induced delayed neuropathy. [81,82] Reaction of butyrylcholinesterase with 2-(o-cresyl)-4H-1,2, 3-benzodioxaphosphoran-2-one results in a unique, phosphobutyrylcholinesterase adduct [83,84] which is a convenient marker for in vivo exposure to tri-o-cresyl phosphate. Purification of butyrylcholinesterase from exposed serum using ion-exchange chromatography (Q-Sepharose, at pH 4) and procainamide affinity chromatography, followed by pepsin digestion and enrichment/ concentration of the phospho-peptide using titanium-oxide affinity chromatography (Titansphere, TiO 2 ) creates a preparation from which as little as 0.05% phosphorylated butyrylcholinesterase can be detected using matrix-assisted laser desorption/ionization TOF-MS. [85] Testing of the serum from random airline passengers immediately after flying has shown that approximately 50% have phosphorylated butyrylcholinesterase, despite the fact that those passengers showed no signs of toxicity.…”