The mass-to-charge ratio scale
โ Scribed by R.C. Dougherty; A.G. Marshall; J.R. Eyler; D.E. Richardson; R.E. Smalley
- Book ID
- 103995857
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 456 KB
- Volume
- 5
- Category
- Article
- ISSN
- 1044-0305
No coin nor oath required. For personal study only.
โฆ Synopsis
Increases in the capacity for accurately measuring the mass-to-charge ratio of specific gas-phase ions justify the reconsideration and standard definition of the gas-phase mass-to-charge ratio scale and the clearly denned connection of that scale to condensed phases. We propose that the chemical mass standard for solids and the gas phase be based upon the mass of carbon-12 buckminsterfulierene ((12)C60). The mass-to-charge ratio scale in the gas phase would be based upon the mass of gas-phase (12)C60, the mass of the electron, and the electron charge in atomic units. As mass measurement accuracy improves, corrections to this mass-to-charge ratio standard are anticipated for the vaporization energy of the 12C60 molecule and its ionization potential or electron affinity. We propose that the positive ion scale be set by the mass-to-charge ratio of (12)C 60 (+) as (+)719.9994514ยฑ0.0000004 u per electron charge. We propose that the negative ion mass scale be set by the mass-to-charge ratio of (12)C 60 (-) as (-)720.0005484ยฑ0.0000004 u per electron charge.
๐ SIMILAR VOLUMES
Proton transfer reactions of multiply charged ions at high mass-to-charge ratios were explored with a low frequency quadrupole mass spectrometer. This instrument enabled a qualitative comparison of proton transfer reaction rates at low charge states for ions generated by electrospray ionization (ESI