Orazbayeva, Dina published the artcileDetermination of transformation products of unsymmetrical dimethylhydrazine in water using vacuum-assisted headspace solid-phase microextraction, Application of 1-Methylpyrazole, the publication is Journal of Chromatography A (2018), 30-36, database is CAplus and MEDLINE.
A new, sensitive and simple method based on vacuum-assisted headspace solid-phase microextraction (Vac-HSSPME) followed by gas chromatog.-mass-spectrometry (GC-MS), is proposed for the quantification of rocket fuel unsym. dimethylhydrazine (UDMH) transformation products in water samples. The target transformation products were: pyrazine, 1-methyl-1H-pyrazole, N-nitrosodimethylamine, N,N-dimethylformamide, 1-methyl-1H-1,2,4-triazole, 1-methyl-imidazole and 1H-pyrazole. For these analytes and within shorter sampling times, Vac-HSSPME yielded detection limits (0.5-100 ng L-1) 3-10 times lower than those reported for regular HSSPME. Vac-HSSPME sampling for 30 min at 50 °C yielded the best combination of analyte responses and their standard deviations (<15%). 1-Formyl-2,2-dimethylhydrazine and formamide were discarded because of the poor precision and accuracy when using Vac-HSSPME. The recoveries for the rest of the analytes ranged between 80 and 119%. The modified Mininert valve and Thermogreen septum could be used for automated extraction as it ensured stable analyte signals even after long waiting times (>24 h). Finally, multiple Vac-HSSME proved to be an efficient tool for controlling the matrix effect and quantifying UDMH transformation products.
Journal of Chromatography A published new progress about 930-36-9. 930-36-9 belongs to pyrazoles-derivatives, auxiliary class Pyrazole, name is 1-Methylpyrazole, and the molecular formula is C4H6N2, Application of 1-Methylpyrazole.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics