ASTM_E_2695_-_09.pdf

Designation:E269509Standard Guide forInterpretation of Mass Spectral Data Acquired with Time-of-Flight Secondary Ion Mass Spectroscopy1This standard is issued under the fixed designation E2695;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This guide provides time-of-flight secondary ion massspectrometry(ToF-SIMS)users with a method for forms ofinterpretation of mass spectral data.This guide is applicable tomost ToF-SIMS instruments and may or may not be applicableto other forms of secondary icon mass spectrometry(SIMS).1.2 This guide does not purport to address methods ofsample preparation.It is the responsibility of the user to adhereto strict sample preparation procedures in order to minimizecontamination and optimize signals.See Guide E1078 andISO 18116 for sample preparation guidelines.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.4 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2E673 Terminology Relating to Surface Analysis(Withdrawn2012)3E1078 Guide for Specimen Preparation and Mounting inSurface AnalysisE1504 Practice for Reporting Mass Spectral Data in Second-ary Ion Mass Spectrometry(SIMS)E1635 Practice for Reporting Imaging Data in SecondaryIon Mass Spectrometry(SIMS)2.2 ISO Standards:4ISO 23830 Repeatability and Constancy of the RelativeIntensity ScaleISO 18115:2007 Terminology Related to Surface ChemicalAnalysisISO 18116 Guidelines for Preparation and Mounting ofSpecimens for Analysis3.Terminology3.1 DefinitionsSeeTerminologyE673andISO 18115:2007 for definitions of terms used in SIMS.3.2 Definitions of Terms Specific to This Standard:3.2.1 cationizationthe process by which a positivelycharged ion is formed,whereby a neutral molecule is combinedwith a cation,usually a metal ion;the resulting peaks are oftenreferred to as cationized peaks.3.2.2 deprotonated molecular iona molecule that has losta proton to form a negative ion.3.2.3 exact massmeasurement of the mass of an ion withsufficient accuracy to provide an unequivocal identification ofits elemental and isotopic composition(1);5for example,apeak located at m/z 43.0184 in a positive ion mass spectrum ismost likely C2H3O+and cannot be C3H7+(m/z 43.0547).3.2.4 fragment ionthe molecular ion,when struck by aprimary ion beam,will typically break up into smaller pieces;this process is called fragmentation;a charged dissociationproduct arising from the fragmentation process is called afragment ion.3.2.5 fragmentation patternthe fragmentation of molecu-lar species results in a series of peaks that are characteristic ofthe molecules underlying structure;this series of peaks isreferred to as the fragmentation pattern of the molecule.3.2.6 m/zthe X-axis of a mass spectrum is labeled as m/z,defined as the mass of the ion,in daltons,divided by the chargeof the ion,where most ions are singly charged.1This practice is under the jurisdiction of ASTM Committee E42 on SurfaceAnalysis and is the direct responsibility of Subcommittee E42.06 on SIMS.Current edition approved May 1,2009.Published January 2010.DOI:10.1520/E2695-09.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from International Organization for Standardization(ISO),1,ch.dela Voie-Creuse,Case postale 56,CH-1211,Geneva 20,Switzerland,http:/www.iso.ch.5The boldface numbers in parentheses refer to a list of references at the end ofthis standard.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.2.7 mass defectwhen a peaks exact mass is locatedslightly below nominal mass.3.2.8 mass excesswhen a peaks exact mass is locatedslightly above nominal mass.3.2.9 mass resolution(DM)the measured full width at halfmaximum intensities of spectral peaks above their local back-grounds.3.2.10 molecular ionan ion formed by the removal of(positive ions)or addition of(negative ions)one or moreelectrons to a molecule,without fragmentation of the molecu-lar structure.3.2.11 nominal massparticle mass,in daltons rounded tothe nearest integer.3.2.12 protonated molecular iona molecule that hasgained a proton to form a positive ion.3.2.13 resolving powerthe ratio M/DM where DM is thefull width at