The employment of chemical weapons by rogue states and/or terrorist organizations is an ongoing concern in the United States. The quantitative analysis of nerve agents must be rapid and reliable for use in the private and public sectors. Current methods describe a tedious and time-consuming derivatization for gas chromatography-mass spectrometry and liquid chromatography in tandem with mass spectrometry. Two solid-phase extraction (SPE) techniques for the analysis of @entity4252 and @entity27025 are described with the utilization of isotopically enriched analytes for quantitation via atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (APCI-Q-TOF- @entity15 ) that does not require derivatization. Solid-phase extraction-isotope dilution mass spectrometry (SPE-IDMS) involves pre-equilibration of a naturally occurring sample with an isotopically enriched standard. The second extraction method, i-Spike, involves loading an isotopically enriched standard onto the SPE column before the naturally occurring sample. The sample and the spike are then co-eluted from the column enabling precise and accurate quantitation via IDMS. The SPE methods in conjunction with IDMS eliminate concerns of incomplete elution, matrix and sorbent effects, and @entity15 drift. For accurate quantitation with IDMS, the isotopic contribution of all atoms in the target molecule must be statistically taken into account. This paper describes two newly developed sample preparation techniques for the analysis of nerve agent surrogates in drinking water as well as statistical probability analysis for proper molecular IDMS. The methods described in this paper demonstrate accurate molecular IDMS using APCI-Q-TOF- @entity15 with limits of quantitation as low as 0.400 mg/kg for @entity4252 and 0.031 mg/kg for @entity27025 .

Improved sample preparation of XXXX and @entity27025 by EPA method 6800A and time-of-flight mass spectrometry using novel solid-phase extraction.

@entity4252 :: ('CHEBI:27744', 'Chemical') :: ['glyphosate'] @entity27025 :: ('MESH:C032627', 'Chemical') :: ['methylphosphonic acid'] @entity15 :: ('MESH:D009103', 'Disease') :: ['MS']
@entity4252 :: (CHEBI:27744,Chemical) :: ['glyphosate']
