Chemical Sciences: A Manual for CSIR-UGC National Eligibility Test for Lectureship and JRF/Resolution (mass spectrometry)

In mass spectrometry, resolution measures of the ability to distinguish two peaks of slightly different mass-to-charge ratios ΔM, in a mass spectrum. Resolution and Resolving Power There are two different definitions of resolution and resolving power in mass spectrometry. IUPAC definition The IUPAC definition for resolution in mass spectrometry is = resolution = resolving power where a larger resolution indicates a better separation of peaks.resolution in mass spectroscopy R05318 This definition is used in a number of mass spectrometry texts.Mass Spectrometry: Organic Chemical Applications Biemann Klaus 1962 McGraw-Hill New York 0070052352 13 Tureček, František; McLafferty, Fred W. Interpretation of mass spectra University Science Books Sausalito, Calif 1993 0-935702-25-3 Watson, J. S. Introduction to mass spectrometry Lippincott-Raven Philadelphia 1997 0-397-51688-6 Ashcroft, Alison E. Ionization methods in organic mass spectrometry Royal Society of Chemistry Cambridge, Eng 1997 0-85404-570-8 JURGEN H. GROSS; Jnrgen H. Gross Mass Spectrometry: A Textbook Springer-Verlag Berlin 2004 3-540-40739-1 Todd, John F. J.; March, Raymond E. Quadrupole ion trap mass spectrometry Wiley-Interscience New York 2005 0-471-48888-7 Siuzdak, Gary The Expanding Role of Mass Spectrometry in Biotechnology, Second Edition MCC Press 2006 0-9742451-2-7 Stroobant, Vincent; Hoffmann, Edmond de Mass spectrometry: principles and applications J. Wiley London 2007 0-470-03310-X Ingvar Eidhammer Computational methods for mass spectrometry proteomics John Wiley & Sons Chichester 2007 0-470-51297-0 This use is also implied by the term "high-resolution mass spectrometry."VanLear GE, McLafferty FW Biochemical aspects of high-resolution mass spectrometry Annu. Rev. Biochem. 38 289–322 1969 4896241 10.1146/annurev.bi.38.070169.001445 http://arjournals.annualreviews.org/doi/abs/10.1146/annurev.bi.38.070169.001445?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dncbi.nlm.nih.gov A high value for resolution corresponding to good separation of peaks is similar to the convention used with chromatography separations,resolution in gas chromatography]] R05317 although it is important to note that the definitions are not the same.Blumberg LM, Kle MS Metrics of separation in chromatography J Chromatogr A 933 1-2 1–11 2001 November 11758739 10.1016/S0021-9673(01)01256-0 High resolution indicating better peak separation is also used in ion mobility spectrometryKarpas, Zeev; Eiceman, Gary Alan Ion mobility spectrometry CRC Press Boca Raton 2005 0-8493-2247-2 IUPAC defines Δm as the resolving power.resolving power in mass spectrometry R05321 Resolving power definition Some mass spectrometrists use the definition that is similar to definitions used in some other fields of physics and chemistry. In this case, resolving power is defined as: = resolving power. The minimum peak separation ΔM which allows to distinguish two ion species is then called: = resolution. Resolution and resolving power, when defined in this way, are consistent with IUPAC recommendations for microscopy, optical spectroscopy.resolution in optical spectroscopy R05319resolving power in optical spectroscopy R05322 and ion microscopy (SIMS) resolving power in ion microscopy I03221 but not gas chromatography.resolution in gas chromatography R05317 This definition also appears in some mass spectrometry texts.David O. Sparkman Mass Spectrometry Desk Reference Global View Pub Pittsburgh 2006 0-9660813-9-0 Sparkman, O. David Introduction to mass spectrometry: instrumentation, applications and strategies for data interpretation John Wiley & Sons Chichester 2007 0-470-51634-8 Dass, Chhabil Fundamentals of contemporary mass spectrometry John Wiley & Sons Chichester 2007 0-471-68229-2 Measuring peak separation There are several ways to define the minimum peak separation ΔM in mass spectrometry, therefore it is important to report the method used to determine mass resolution when reporting its value. The two most widely used are the peak width definition and the valley definition. Peak width definition In the peak width definition, the value of Δm is the width of the peak measured at a specified fraction of the peak height, for example 0.5%, 5%, 10% or 50%. The latter is called the full width at half maximum (FWHM). Valley definition The valley definition defines ΔM as the closest spacing of two peaks of equal intensity with the valley (lowest value of signal) between them less than a specified fraction of the peak height. Typical values are 10% or 50%. The value obtained from a 5% peak width is roughly equivalent to a 10% valley. References