𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Anomalies in the molecular ion region in the electron impact mass spectra of α- and β-hydroxyesters

✍ Scribed by Leszek Konopski

Publisher
John Wiley and Sons
Year
1990
Tongue
English
Weight
312 KB
Volume
25
Category
Article
ISSN
1076-5174

No coin nor oath required. For personal study only.

✦ Synopsis

Abstract

In the electron impact mass spectra of some alkyl α‐ and β‐hydroxyesters (introduced using the gas chromatography/mass spectrometry (GC/MS) technique), the absence of the molecular ion M^+·^ and the presence of the [M + 1]^+^ ion instead is observed. This phenomenon is especially characteristic of C~3~C~6~ glycolates and diethyl malate, and is due to chemical auto‐ionization—ion‐molecule reactions in the high concentration gradient at the top of the GC peak. The existence of the [M  2]^+·^, [M −1]^+^ and M^+·^ ions in the mass spectra of other β‐ and α‐hydroxyesters is discussed.

📜 SIMILAR VOLUMES

Formation of [M − H]+ ions in electron i
Formation of [M − H]+ ions in electron impact mass spectra of nitrosocarbonyl compounds α- and γ-nitrosocarbonyl compounds
✍ Leszek Konopski 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 317 KB

The presence of the [M + HI+ ions and the absence of the monomer molecular ions M" in the mass spectra of some tertiary a-and y-nitrosocarbonyl compounds is reported. This effect is caused by the rearrangement of the mobile hydrogen in the a-carbonyl position in the fragmentation pattern of the dime

Structures of [M–44]+ ions in the electr
Structures of [M–44]+ ions in the electron impact and fast atom bombardment mass spectra of the β-blocker nipradilol with a nitrate ester group
✍ Michiaki Yoneda; Kazuo Tsujimoto; Mamoru Ohashi; Masami Shiratsuchi; Yasushi Ohk 📂 Article 📅 1990 🏛 John Wiley and Sons 🌐 English ⚖ 348 KB

Both electron impact (EI) and fast atom bombardment (liquid secondary ion mass spectrometry) (FAB(LS1MS)) spectra of the antibypertensive drug nipradilol (3,4-dihydro-&(2-hydroxy-3-isopropylamino)propoxy-~nitroxy-ZH-1-benzopyran) and it analogues exhibit intense [M -44]+ peaks. However, high-resolut