Mass spectra and appearance energies of cationic fragments for electron ionization of 2-butanol

In this work, the mass spectrum (MS) and the appearance energies (AEs) of the ionic fragments formed in the collisions of electrons with 2-butanol were studied using a HIDEN—EPIC300 mass spectrometer. The MS was acquired for the electron impact energy of 70 eV, in the mass region of 1–75 amu and with a mass resolution of 1 amu. Here we observed the formation of 51 cationic fragments, which is a significant extension to the data previously reported in the literature. The relative abundances of the registered peaks in the MS compare reasonably well with the available values reported in the literature, where such a comparison can be made. The AEs were determined from the acquisition of ionic fragmentation curves of 2-butanol, for the electron impact energies covering the region of the ionic fragment formation threshold up to about ten eV above that value. The extended Wannier law was applied to obtain the AEs and Wannier exponents (p) of the fragments recorded in the MS, with relative intensities typically > 0.5% of the most intense fragment. This yielded data for 38 fragments, for which data of 30 of those fragments are reported for the first time in this work.