Determination of transformation products of 1,1-dimethylhydrazine by gas chromatography–tandem mass spectrometry

Abstract

A method is proposed for the highly sensitive simultaneous determination of eight major products of oxidative transformations of 1,1-dimethylhydrazine, widely used as a rocket fuel (formaldehyde dimethylhydrazone, acetaldehyde dimethylhydrazone, 2-furaldehyde dimethylhydrazone, 1,1,4,4-tetramethyl-2-tetrazene, N,N-dimethylformamide, N-nitrosodimethylamine, 1-methyl-1H-1,2,4-triazole and 1-formyl-2,2dimethylhydrazine) by gas chromatography–tandem mass spectrometry. The detection parameters in the MRM mode are optimized. The conditions for the efficient separation of analytes on an HP-INNOWAX polar stationary phase are chosen. The detection limits achieved are in the range 0.3–2.3 ng/mL, which is 1?2 orders of magnitude lower than those for the GC/MS method. The developed approaches are tested in the analysis of real samples, surface water of peaty swamp with high contents of organic substance taken at the place of impact of the first rocket stage. It is found that N,N-dimethylformamide and 1-methyl-1H-1,2,4-triazole are predominant among the studied transformation products in natural waters. The results obtained are of great importance for the assessment of the environmental impacts of space rocket activities.