Application of isobutane and ammonia chemical ionization mass spectrometry for the analysis of volatile terpene alcohols and esters

Abstract

The ionization and fragmentation behaviour of mono-and sesqui-terpene alcohols and esters in CI mass spectrometry was investigated. The reagent gases used were isobutane and ammonia. Isobutane yields the species [MH]' as the quasimolecular ions which, however, are extremely small for many of the investigated compounds.Ammonia gives intense [M + 18]+ quasimolecular adduct ions. The assignment of the molecular mass is more reliable in ammonia than in isobutane CI. Alcohols and esters form characteristic fragment ions. Alcohols show the mass difference of 18 mass units and esters display the difference of the respective acid in the patterns of the CI spectra. This fact enables one to distinguish the classes of the terpene alcohols and esters by means of CI. Particular compounds, as well ascisltranr and stereoisomers, can be differentiated by their ion patterns. CI spectra are strongly dependent on experimental conditions. High ion source temperature favours fragmentation diminishing the relative intensity of the quasimolecular ion. High ammonia reagent gas pressure reduces the relative intensities of fragment ions enhancing the relative abundancies of the quasimolecular adduct ions.

Analysis of the essential oil from the roots of Eupatorium cannabinum subsp. corsicum (L.) by GC, GC‐MS and 13C‐NMR

“…Finally, the molecular and quasimolecular ions of the benzofuran euparin (106) were in accord with those obtained in our previous study (Paolini et al, 2005); in effect, these components were characterized by: These results on the chemical ionization of monoterpene esters were in accordance with those previously reported in the study of aerial parts of E. cannabinum subsp. corsicum (Paolini et al, 2005) and with those previously reported in the literature (Bruins, 1979;Hendriks et al, 1985;Lange and Schutze, 1987). The information obtained by GC-CI/MS has been used with respect to unknown esters and diesters for: (i) the determination of molecular mass; (ii) the differentiation of compounds with similar EI/MS; and (iii) the identification of acid and alcohol portions.…”

Effect of dietary Ginkgo biloba leaf on the growth performance and nonspecific immunity of red swamp crayfish Procambarus clarkii

“…Many studies have shown that crustaceans and aquatic animals' growth performance improvements come from various medicinal herbs' extracts (Abdel-Latif et al, 2021;Cheng, 2019;Dong et al, 2018;Pan et al, 2018;Tan et al, 2018). For GBL, it can send out fragrance to stimulate the appetite of crayfish and improve the digestibility and absorption rate of feed in the digestive tract of the crayfish (Lange and Schultze, 2010;Jannathulla and Dayal, 2022). In addition, it is rich in protein.…”