Gaseous acidity and basicity scales as guides to chemical ionization in reversed-phase liquid chromatography-mass spectrometry with direct liquid introduction
| Autor: | M.M. Bursey, Carol E. Parker, S.J. Gaskell, Richard W. Smith |
|---|---|
| Rok vydání: | 1985 |
| Předmět: |
Chemical ionization
Acetonitriles Chromatography Formic acid Methanol Organic Chemistry Analytical chemistry Atmospheric-pressure chemical ionization General Medicine Hydrogen-Ion Concentration Mass spectrometry Biochemistry Mass Spectrometry Analytical Chemistry chemistry.chemical_compound chemistry Ionization Solvents Ammonium formate Direct electron ionization liquid chromatography–mass spectrometry interface Acetonitrile Chromatography Liquid |
| Zdroj: | Journal of Chromatography A. 347:61-74 |
| ISSN: | 0021-9673 |
| DOI: | 10.1016/s0021-9673(01)95469-x |
| Popis: | During direct liquid introduction (DLI) liquid chromatography-mass spectrometry (LC-MS), the detectability of acetone is shown to be predictable, based on consideration of the gas-phase acidities and basicities of solvents methanol and acetonitrile and modifiers formic acid and ammonium formate. Consequently, ion formation in DLI LC-MS resembles gas-phase chemical ionization processes; since the order of acidities is altered in solution, solution ionization must be much less important than gas-phase. Ion populations could be predicted on the basis of gas-phase proton affinities and acidities: acetone could be detected in all solvent mixture by positive ions, but it was not readily detected by negative ions when acid was also present. In solvents without additives it was always detected. |
| Databáze: | OpenAIRE |
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