Determination of 1,1-Dimethylhydrazine and its Transformation Products in Soil by Zwitterionic Hydrophilic Interaction Liquid Chromatography/Tandem Mass Spectrometry

1,1-Dimethylhydrazine is widely used as a fuel by some classes of carrier rockets. Being an extremely toxic and reactive substance, it gives a number of hazardous transformation products and poses a serious threat to the ecological state of the launch sites and territories used for landing of spent rocket parts. On the basis of studies of the retention of analytes on the sulfobetaine zwitterionic stationary phase, the HILIC–ESI-MS/MS method for simultaneous and rapid determination of unsymmetrical dimethylhydrazine and six major products of its transformation (methylhydrazine, N-nitrosodimethylamine, N,N-dimethylformamide, 1-methyl-1,2,4-1H-triazole, 1,1,4,4-tetramethyl-2-tetrazene, 1,1-dimethylguanidine) was developed. The achieved detection limits for the analytes were 0.02–7 μg L−1 and, for most compounds, they are significantly lower compared to the existing IC–MS/MS method. Direct combination of HILIC–MS/MS with preliminary pressurized extraction with acetonitrile allowed analysis of peat bog soils contaminated with rocket fuel within 40 min, including all sample preparation steps. The developed method was successfully tested on a sample of real soil from the falling place of the spent carrier rocket stage.