Investigation of Features of Mass-Fragmentation of Some N-(N,N-diethylacetamidino)-O-alkylfluorophosphates and Related Alkylfluorophosphonates and their Detection by Liquid Chromatography-High Resolution Mass Spectrometry

Abstract

The timely detection of violations of the Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on Their Destruction (CWC) requires reliable methods for detecting toxic chemicals that can be used for chemical attacks. The purpose of this investigation is to estimate chromatographic and mass-spectral characteristics of some toxic chemicals recently included into Schedule 1 of the Annex on Chemicals of the CWC, in particular N-(N,N-diethylacetamidino)-methylfluorophosphonate (DEAMP), N-(N,N-diethylacetamidino)-O-methylfluorophosphate (DEAOMP) and N-(N,N-diethylacetamidino)-O-ethylfluorophosphate (DEAOEP) and the improvement of the qualification of the Chemical Analytical Control Laboratory experts taking part in the OPCW Proficiency Tests. Materials and methods. The technique of high efficient liquid chromatography coupled with tandem high resolution mass spectrometry (LC-MS/HRMS) was used during the investigation. The results. The results of optimization of conditions of mass-spectrometric detection, selection of optimal pairs of ion reactions and program of gradient elution during separation of chemicals in reversed-phase liquid chromatography were presented. Presented approach was tested in analysis of model aqueous samples; metrological parameters of detection of compounds were estimated. Conclusion. It was shown during investigation that electrospray ionization mass-spectra of DEAMP, DEAOMP and DEAOEP contain intensive peaks of protonated molecular ions, which after further fragmentation produce characteristic product-ions used for identification and high sensitive detection of parent compounds by LC-MS/HRMS. Limits of detection of DEAMP, DEAOMP and DEAOEP were 1.0 ng/mL, 0.5 ng/mL and 0.5 ng/mL, respectively

Keywords

• high-resolution mass-spectrometry
• high-efficiency liquid chromatography
• convention on the prohibition of the development
• production
• stockpiling and use of chemical weapons and on their destruction