Resolution (mass spectrometry): Difference between revisions
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{{Def|The smallest mass difference Δ'''m''' between two equal magnitude peaks such that the valley between them is a specified fraction of the peak height}} | |||
== [[Orange Book]] Definition == | |||
[[Resolution: 10 Per Cent Valley Definition]] | [[Resolution: 10 Per Cent Valley Definition]] | ||
Let two peaks of equal height in a [[Mass Spectrum|mass spectrum]] at masses m and m - Δm be separated by a valley which at its lowest point is just 10% of the height of either peak. For similar peaks at a mass exceeding m , let the height of the valley at its lowest point be more (by any amount) than 10% of either peak. Then the resolution (10% valley definition) is m / Δm. The ratio m /Δm should be given for a number of values of m. | |||
[[Resolution: Peak Width Definition]] | [[Resolution: Peak Width Definition]] | ||
For a single peak made up of singly charged ions at mass m in a [[Mass Spectrum|mass spectrum]], the resolution may be expressed as m / ??????????????????????m, where ??????????????????????m is the width of the peak at a height which is a specified fraction of the maximum peak height. It is recommended that one of three values 50%, 5% or 0.5% should always be used. (Note that for an isolated symmetrical peak recorded with a system which is linear in the range between 5% and 10% levels of the peak, the 5% peak width definition is equivalent to the 10% valley definition. A common standard is the definition of resolution based upon ??????????????????????m being Full Width of the peak at Half its Maximum (FWHM) height. | |||
== Related Terms == | |||
[[Resolving Power (Mass)]] | [[Resolving Power (Mass)]] | ||
Revision as of 18:00, 14 January 2005
| DRAFT DEFINITION |
| Resolution (mass spectrometry) |
|---|
| Related Term(s): |
| Reference(s): |
| This is an unofficial draft definition presented for information and comment. |
Orange Book Definition
Resolution: 10 Per Cent Valley Definition
Let two peaks of equal height in a mass spectrum at masses m and m - Δm be separated by a valley which at its lowest point is just 10% of the height of either peak. For similar peaks at a mass exceeding m , let the height of the valley at its lowest point be more (by any amount) than 10% of either peak. Then the resolution (10% valley definition) is m / Δm. The ratio m /Δm should be given for a number of values of m.
Resolution: Peak Width Definition
For a single peak made up of singly charged ions at mass m in a mass spectrum, the resolution may be expressed as m / ??????????????????????m, where ??????????????????????m is the width of the peak at a height which is a specified fraction of the maximum peak height. It is recommended that one of three values 50%, 5% or 0.5% should always be used. (Note that for an isolated symmetrical peak recorded with a system which is linear in the range between 5% and 10% levels of the peak, the 5% peak width definition is equivalent to the 10% valley definition. A common standard is the definition of resolution based upon ??????????????????????m being Full Width of the peak at Half its Maximum (FWHM) height.
