Dissociative ionization cross sections of isobutanol

The electron impact partial ionization cross sections (PICS) for isobutanol were calculated using variants of the binary encounter Bethe model (BEB). The modified BEB (m-BEB) model and the mass spectrum dependent (MSD) method are used to calculate the PICS of cationic fragments of isobutanol due to electron impact. In the absence of any other data for isobutanol, the present PICS is compared with the PICS data for other isomers of butanol. We also presented the calculated electron impact mass spectrum of isobutanol, 1-butanol, and 2-butanol that is compared with the experimental mass spectrum data. Such data could be useful in the absence of any other experimental data and can be used to estimate the theoretical PICS of the molecules. Moreover, the theoretical EIMS data from quantum chemical mass spectrometry (QCxMS2) method has been used to compute the PICS of the cations.