在研究２－异唑啉衍生物的电子轰击（（ＥＩ）质谱时，发现在四极质谱仪上测试，其质谱图中不出现分子离子峰而产生非常特征的Ｍ十３峰，而在高分辨磁质谱仪上测试，则出现Ｍ＋２峰，同样没有分子离子峰，这种现象在一般有机化合物的质谱中是罕见的。在磁质谱仪上研究了样品汽化温度对［Ｍ＋２］峰的影响，并利用高分辨质谱数据研究其裂解机理。 When studying the electron impact (EI) mass spectra of 2-isoxazoline derivatives, they were found to be tested on a quadrupole mass spectrometer and showed no characteristic molecular ion peak in the mass spectrum resulting in a very characteristic M 10 3 peak, The M + 2 peak and the absence of molecular ion peak are observed on the magnetic mass spectrometer, which is rare in general mass spectrometry of organic compounds. The influence of sample vaporization temperature on [M + 2] peak was studied on a magnetic mass spectrometer, The cleavage mechanism was studied by high resolution mass spectrometry.