Selection of Recording Conditions and Study of Fragmentation of a Peptide Biomarker of Sarin by High-Performance Liquid Chromatography–High-Resolution Mass Spectrometry

The identification of protein biomarkers of chemical warfare agents involves their reliable detection in the blood plasma at trace levels. This is a challenging task in the modern liquid chromatography–mass spectrometry. Existing approaches are based on the formation of tyrosine adducts with alkylmethylphosphonic acids after the cleavage of all proteins. The structure of such adducts is related to the type of the chemical agent used. This study demonstrates the possibility of detecting the tripeptide adduct of isopropylmethylphosphonic acid, obtained by trypsinolysis of the albumin adduct with sarin, in human plasma. The study of the pathways of fragmentation of the analyte ensures the identification of the characteristic features of dissociation that can be used to determine other biomarkers of the application of chemical weapons. The conditions for recording the most intense ion transitions to perform the rapid screening of blood plasma samples for the concentration of the albumin adduct of sarin by filtration with trypsinolysis are proposed.