ASTM_F_2102_-_17.pdf

Designation:F210217Standard Guide forEvaluating the Extent of Oxidation in PolyethyleneFabricated Forms Intended for Surgical Implants1This standard is issued under the fixed designation F2102;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 covers a method for the measurement of therelative extent of oxidation present in HDPE homopolymersand ultra-high-molecular-weight polyethylene(UHMWPE)in-tended for use in medical implants.The material is analyzed byinfrared spectroscopy.The intensity(area)of the carbonylabsorptions(C=O)centered near 1720 cm-1is related to theamount of chemically bound oxygen present in the material.Other forms of chemically bound oxygen(C-O-C,C-O-O-C,C-O-H,and so forth)are not captured by this guide.1.2 Although this guide may give the investigator a meansto compare the relative extent of carbonyl oxidation present invarious UHMWPE samples,it is recognized that other forms ofchemically bound oxygen may be important contributors tothese materials characteristics.1.3 The applicability of the infrared method has beendemonstrated by many literature reports.This particularmethod,using the intensity(area)of the C-H absorptioncentered near 1370 cm-1to normalize for the samplesthickness,has been validated by an Interlaboratory Study(ILS)conducted according to Practice E691.1.4 The following precautionary caveat pertains only to thetest method portion,Section 5,of this specification:Thisstandard may involve hazardous materials,operations,andequipment.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 requirements prior to use.1.5 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE2857 Guide for Validating Analytical Methods3.Terminology3.1 Definitions:3.1.1 bulk oxidation index(BOI)a samples bulk oxidationindex(BOI)is the average of the oxidation indices collectedover a 500-m section at the center of the sample.3.1.1.1 DiscussionTypically,this is a plateau region withthe smallest oxidation indices.3.1.1.2 DiscussionFor samples less than about 8 to 10 mmthick,this central region may display the samples highestoxidation indices,depending on its state of oxidation.3.1.2 depth locator(DL)a measurement of the distancefrom the articular surface,or surface of interest,that a spectrumwas collected and a corresponding OI calculated.3.1.3 oxidation index(OI)an oxidation index(OI)isdefined as the ratio of the area of the carbonyl absorptionpeak(s)centered near 1720 cm-1to the area of the absorptionpeak(s)centered near 1370 cm-1,as shown in Fig.1.Note thatthe peak areas are computed after subtracting out the appro-priate baseline,as further discussed in Section 6.3.1.4 oxidation index profilean oxidation index profile isthe graphical representation of variation of the samplesoxidation index with distance from its articular surface or thesurface of interest.This is a plot of an OI versus DL.Typically,the graph will show the profile through the entire thickness ofthe sample.3.1.5 surface oxidation index(SOI)a samples surfaceoxidation index(SOI)is the average of the oxidation indicesfrom the samples articular surface,or the surface of interest,toa depth of 3-mm subsurface.1This guide is under the jurisdiction of ASTM Committee F04 on Medical andSurgical Materials and Devices and is the direct responsibility of SubcommitteeF04.15 on Material Test Methods.Current edition approved Sept.1,2017.Published September 2017.Originallyapproved in 2001.Last previous edition approved in 2013 as F2102 13.DOI:10.1520/F2102-17.2For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee