Mass spectral studies of silyl derivatives of partially hydrolyzed products of nitrogen mustards: Important markers of nitrogen mustard exposure

Abstract

Rationale: Nitrogen mustards (NMs) are vesicant class of chemical warfare agents. From the viewpoint of the Chemical Weapons Convention partially hydrolyzed products of nitrogen mustards (pHpNMs) are considered as important markers of nitrogen mustard exposure. The detection of pHpNMs from biological or environmental samples is highly useful for obtaining forensic evidence of exposure to NMs.Methods: Gas chromatography interfaced with tandem mass spectrometry (GC/MS/ MS) is a widely used tool for the identification and sensitive detection of metabolites of NMs in complex matrices. The pHpNMs were derivatized using silylating agents as they are highly polar and non-amenable to GC. The mass spectral studies of these silyl derivatives of pHpNMs were performed using GC/MS/MS in both electron ionization (EI) and chemical ionization (CI) mode. Results:Various approaches have been proposed to assess the fragmentation pathways of the trimethylsilyl (TMS) and tert-butyldimethylsilyl (TBDMS) derivatives of pHpNMs. All the proposed fragmentation pathways were based on the product and/or precursor ion scanning of corresponding ions in both EI and CI mode. In the case of EI, most of the fragmentation pathways involved either α-cleavage or inductive cleavage.Conclusions: This is the first report on the MS study of the silyl derivatives of pHpNMs. The study of the two different derivatives of pHpNMs using both EI-and CI-MS provides a reliable, unambiguous identification of pHpNMs in complex environmental and biomedical matrices (such as plasma and urine) during any verification activities.

Mass spectral fragmentation of perfluoroacyl derivatives of half nitrogen mustards for their detection by gas chromatography/mass spectrometry

“…The halfNMs were synthesized using our previously reported method 11 with some modification. Briefly, 1 mg of the salt of the NMs was dissolved in 1 mL of acetone/water (2:1 v/v) and incubated at room temperature with vigorous stirring.…”

“…In a previous article GC/MS-based identification of halfNMs after derivatization by silylation was reported. 11 However, silylation of halfNMs has disadvantages: a long derivatization time, a high derivatization temperature, and a chromatogram with significant background peaks. These problems can be overcome by substituting derivatization by perfluoroacylation.…”

Development of a SAW poly(epichlorohydrin) gas sensor for detection of harmful chemicals

“…Therefore, research on the detection of HD by sensing technologies has remarkable practical and safety importance. In recent years, the detection of CWAs at very low concentrations by using instruments or sensing devices with different mechanisms, such as mass spectroscopy, 6,7 Raman spectroscopy, 8,9 capillary electrophoresis, 10 fluorescence spectroscopy, 11 and ion mobility spectrometry, 12 have been developed. However, because of the large size of instruments and equipment, high price, complex operation, need for sample pretreatment, and professional training of operators, these detection technologies have not met the needs of on-site rapid detection.…”

Development of a method for the derivatization of ethanolamines and its application to sand samples

“…14 However, no quantitative data were demonstrated. Methods for sample-applied derivatization of partially hydrolyzed nitrogen mustards were created using silylation, 15 trifluoroacetylation using TFAI and heptafluorobutyrylation. 16 In the last case, better results were obtained in comparison to silylation.…”