title: Improvements of the fluoride reactivation method for the verification of nerve agent exposure.
abstract: One of the most appropriate biomarkers for the verification of organophosphorus nerve agent exposure is the conjugate of the nerve agent to butyrylcholinesterase (BuChE). The phosphyl moiety of the nerve agent can be released from the BuChE enzyme by incubation with fluoride ions, after which the resulting organophosphonofluoridate can be analyzed with gas chromatography-mass spectrometry (GC-MS). This paper describes recent improvements of the fluoride-induced reactivation in human plasma or serum samples by enhancing the sample preparation with new solid-phase extraction cartridges and the MS analysis with large volume injections. Analysis is performed with thermal desorption GC with either mass selective detection with ammonia chemical ionization or high-resolution MS with electron impact ionization. The organophosphorus chemical warfare agents analyzed in this study are O-ethyl S-2-diisopropylaminoethyl methylphosphonothiolate, ethyl methylphosphonofluoridate, isopropyl methylphosphonofluoridate (sarin, GB), O-ethyl N,N-dimethylphosphoramidocyanidate, ethyl N,N-dimethylphosphoramidofluoridate, and cyclohexyl methylphosphonfluoridate. Detection limits of approximately 10 pg/mL plasma were achieved for all analytes, which corresponds to 0.09% inhibition with GB on a sample with normal BuChE levels.
authors.affiliation: TNO-Prins Maurits Laboratory, P.O. Box 45, 2280 AA Rijswijk, The Netherlands.
authors.forename: Carla E A M
authors.initials: CE
authors.lastname: Degenhardt
authors.forename: Kees
authors.initials: K
authors.lastname: Pleijsier
authors.forename: Marcel J
authors.initials: MJ
authors.lastname: van der Schans
authors.forename: Jan P
authors.initials: JP
authors.lastname: Langenberg
authors.forename: Kerry E
authors.initials: KE
authors.lastname: Preston
authors.forename: Maria I
authors.initials: MI
authors.lastname: Solano
authors.forename: V L
authors.initials: VL
authors.lastname: Maggio
authors.forename: John R
authors.initials: JR
authors.lastname: Barr
mesh_terms: D015415:Biomarkers / Q000097:blood; D002091:Butyrylcholinesterase / Q000378:metabolism; D002619:Chemical Warfare Agents / Q000032:analysis / Q000493:pharmacokinetics / Q000506:poisoning; D002801:Cholinesterase Reactivators; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring / Q000379:methods*; D004912:Erythrocytes / Q000187:drug effects / Q000201:enzymology; D005459:Fluorides / Q000378:metabolism / Q000494:pharmacology*; D008401:Gas Chromatography-Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D002619:Chemical Warfare Agents; D002801:Cholinesterase Reactivators; D002091:Butyrylcholinesterase; D005459:Fluorides