Ionização por impacto de elétrons da L-Carvona: determinação de limiares de energia de formação de cátions e expoentes de Wannie

Abstract

The ionic fragmentation process of L-Carvone by electron impact was investigated in this work, using a Hiden Quadrupole Mass Spectrometer (EPIC 300), composed of a radiofrequency head, capable of measuring masses in the region of 1-300 a.m.u., with resolution of 1 a.m.u., operating in the residual gas analysis mode. The L- Carvone mass spectrum was recorded at 70 eV electron impact energy and normalized to the base peak observed at 82 a.m.u.. It was recorded 118 peaks in this spectrum, 4 of them with abundances greater than 50%. The assignment of these peaks was based on the literature data, as well as on the Appearance Energy - AE data generated in this work. To the best of our knowledge, we recorded and studied for the first time in this work, the formation of numerous ionic fragments. It were also recorded for the first time, the thresholds curves of formation of 14 cationic fragments, for which 18 AEs and their Wannier (p) potentials were determined. The results of AE for the mass of 82 u.m.a. and, the ionization energy for L-Carvone (150 u.m.a.) found in this work are in a good agreement with the data published in the literature.