ASTM_E_168_-_16.pdf

Designation:E16816Standard Practices forGeneral Techniques of Infrared Quantitative Analysis1This standard is issued under the fixed designation E168;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.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 These practices cover the techniques most often used ininfrared quantitative analysis.Practices associated with thecollection and analysis of data on a computer are included aswell as practices that do not use a computer.1.2 This practice does not purport to address all of theconcerns associated with developing a new quantitativemethod.It is the responsibility of the developer to ensure thatthe results of the method fall in the desired range of precisionand bias.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.Specific hazardstatements appear in Section 6,Note A4.7,Note A4.11,andNote A5.6.2.Referenced Documents2.1 ASTM Standards:2E131 Terminology Relating to Molecular SpectroscopyE334 Practice for General Techniques of Infrared Micro-analysisE932 Practice for Describing and Measuring Performance ofDispersive Infrared SpectrometersE1252 Practice for General Techniques for Obtaining Infra-red Spectra for Qualitative AnalysisE1421 Practice for Describing and Measuring Performanceof Fourier Transform Mid-Infrared(FT-MIR)Spectrom-eters:Level Zero and Level One TestsE1655 Practices for Infrared Multivariate QuantitativeAnalysis3.Terminology3.1 For definitions of terms and symbols,refer to Terminol-ogy E131.4.Significance and Use4.1 These practices are intended for all infrared spectrosco-pists.For novices,these practices will serve as an overview ofpreparation,operation,and calculation techniques.For experi-enced persons,these practices will serve as a review whenseldom-used techniques are needed.5.Apparatus5.1 The infrared techniques described here assume that theequipment is of at least the usual commercial quality and meetsthe standard specifications of the manufacturer.For dispersiveinstruments,also refer to Practice E932.For Fourier Transformand dispersive instruments,also refer to Practices E1421 andE932 respectively,and for microanalysis with these instru-ments see Practice E334.5.2 In developing a spectroscopic method,it is the respon-sibility of the originator to describe the instrumentation and theperformance required to duplicate the precision and bias of amethod.It is necessary to specify this performance in termsthat can be used by others in applications of the method.6.Hazards6.1 Users of these practices must be aware that there areinherent dangers associated with the use of electricalinstrumentation,infrared cells,solvents,and other chemicals,and that these practices cannot and will not substitute for apractical knowledge of the instrument,cells,and chemicalsused in a particular analysis.7.Considerations for Quantitative InfraredMeasurements7.1 Quantitative infrared analysis is commonly done withgrating,filter,prism,or interferometer instruments.The fol-lowing guidelines for setting up an analytical procedure areappropriate:1These practices are under the jurisdiction of ASTM Committee E13 onMolecular Spectroscopy and Separation Science and are the direct responsibility ofSubcommittee E13.03 on Infrared and Near Infrared Spectroscopy.Current edition approved April 1,2016.Published June 2016.Originallyapproved in 1964.Last previous edition approved in 2006 as E168 06 which waswithdrawn January 2015 and reinstated in April 2016.DOI:10.1520/E0168-16.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 7.1.1 Always operate the instrument in the most stable andreproducible conditions attainable.This includes instrumentwarm-up time,sample temperature equilibration,and exactreproduction of instrument performance tests for both stan-dards and samples.After calibration,use equivalent settings foranalyses.For all infrared instruments,refer to the manufactur-ers recommendations for the instrument settings.Aftercalibration,use these same settings for analysis.7.1.2 The absorbance values at analytical wavenumbersshould fall within the acceptably acc