Resolving power (in mass spectrometry)

IUPAC RECOMMENDATIONS 2013
Resolving power (in mass spectrometry) {{{acronym}}}
mass resolving power Measure of the ability of a mass spectrometer to provide a specified value of mass resolution. Note: The procedure by which Δ(m/z) was defined and measured, and the m/z value at which the measurement was made, should be reported.
Related Term(s):
Reference(s): Revised from IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the Orange Book). Definitive Rules, 1979. Compiled by J. Inczdy, T. Lengyel, A. M. Ure. Blackwell Scientific Publications, Oxford (1997). On-line corrected version: http://www.iupac.org /publications/analytical compendium (2000). IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins.
From Definitions of Terms Relating to Mass Spectrometry (IUPAC Recommendations 2013); DOI: 10.1351/PAC-REC-06-04-06 © IUPAC 2013.
Index of Recommended Terms

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Orange Book

ORANGE BOOK DEFINITION IUPAC. Analytical Division. Compendium of Analytical Nomenclature (the Orange Book). Definitive Rules, 1979 (see also Orange Book 2023)
Resolving power (in mass spectrometry)
The ability to distinguish between ions differing in the quotient mass/charge by a small increment. It may be characterized by giving the peak width, measured in mass units, expressed as a function of mass, for at least two points on the peak, specifically for 50% and for 5% of the maximum peak height.
IUPAC 1997 Orange Book Chapter 12
Index of Orange Book Terms

Gold Book

GOLD BOOK DEFINITION IUPAC. Compendium of Chemical Terminology, 2nd ed. (the Gold Book). Compiled by A. D. McNaught and A.Wilkinson. Blackwell Scientific Publications, Oxford (1997).
Resolving power (in mass spectrometry)
Resolving power (mass spectrometry) http://goldbook.iupac.org/R05321.html The ability to distinguish between ions differing in the quotient mass/charge by a small increment. It may be characterized by giving the peak width, measured in mass units, expressed as a function of mass, for at least two points on the peak, specifically at fifty percent and at five percent of the maximum peak height. mass resolving power http://goldbook.iupac.org/M03730.html Commonly and also acceptably defined in terms of the overlap (or 'valley') between two peaks. Thus for two peaks of equal height, masses and , when there is overlap between the two peaks to a stated percentage of either peak height (10% is recommended), then the resolving power is defined as . The percentage overlap (or 'valley') concerned must always be stated. Source: PAC, 1978, 50, 65 (Recommendations for symbolism and nomenclature for mass spectroscopy) on page 72
IUPAC Gold Book
Index of Gold Book Terms

Controversy

QUOTED TEXT FROM IUPAC RECOMMENDATIONS 2013
The IUPAC definition of resolution in mass spectrometry expresses this value as m/?m, where m is the mass of the ion of interest and ?m is the peak width (peak width definition) or the spacing between two equal intensity peaks with a valley between them no more than 10 % of their height (10 % valley definition) [1]. Resolving power in mass spectrometry is defined as the ability of an instrument or measurement procedure to distinguish between two peaks at m/z values differing by a small amount and expressed as the peak width in mass units [2]. Mass resolving power is defined separately as m/?m in a manner similar to that given above for mass resolution [3]. These definitions of mass resolving power and resolving power in mass spectrometry are contradictory, the former is expressed as a dimensionless ratio and the latter as a mass. The definitions for resolution in mass spectrometry and resolving power in mass spectrometry come from Todds 1991 recommendations [4], and the definition for mass resolving power comes from Beynons 1978 recommendations [J. Beynon. Pure Appl. Chem. 50, 65 (1978)]. Beynons work contains no definition for mass resolution. Alternative definitions for resolution and resolving power in mass spectrometry have been proposed [5][6]. It has been suggested that resolution be given by ?m and resolving power by m/?m; however, these definitions are not widely used. The majority of the mass spectrometry community uses resolution as defined by IUPAC. The term resolving power is not widely used as a synonym for resolution. In this document, the IUPAC definition of resolution in mass spectrometry remains in place. The definition of resolving power has been adapted from the current IUPAC definition of mass resolving power.
From Definitions of Terms Relating to Mass Spectrometry (IUPAC Recommendations 2013); DOI: 10.1351/PAC-REC-06-04-06 © IUPAC 2013.