Assessment of the Simultaneous Determination of Unsymmetrical Dimethylhydrazine and Three Transformation Products in Model Solutions by Gas Chromatography–Mass Spectrometry
摘要
Unsymmetrical dimethylhydrazine (UDMH) serves as a component of high-boiling rocket fuel. This highly toxic compound rapidly oxidizes and decomposes in the environment, producing a variety of transformation products. Hygienic standards exist for only a few of these products, specifically dimethylamine (DMA), 1,1,4,4-tetramethyltetrazene (TMT), and N-nitrosodimethylamine (NDMA). Developing a chromatographic–mass spectrometric method for the simultaneous determination of UDMH and its regulated transformation products represents a current analytical challenge. The possibility of simultaneously determining UDMH and three of its transformation products—NDMA, TMT, and DMA—in model solutions was evaluated using gas chromatography–mass spectrometry. Reagents for the derivatization of UDMH and DMA were investigated, followed by the determination of their derivatives, NDMA, and TMT in extracts. The influence of side reaction products on the stability of TMT and on the chromatographic characteristics of the analytes was assessed. A sequential derivatization procedure for UDMH and DMA was developed to enable their determination by gas chromatography–tandem mass spectrometry in a single workflow. Derivatization and extraction conditions were optimized to prevent analyte degradation; the linearity of the analytical signal and reproducibility of the procedure were evaluated, and the stability of solutions in the autosampler was examined.