1、Designation: F1877 05 (Reapproved 2010)F1877 16Standard Practice forCharacterization of Particles1This standard is issued under the fixed designation F1877; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 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 practice covers a series of procedures for characterization of the morphology, number, size, and size distribution ofparticles.
3、 The methods utilized include sieves, optical, SEM, scanning electron microscopy (SEM), transmission electronmicroscopy (TEM), and electrooptical.1.2 These methods are appropriate for particles produced by a number of different methods. These include wear test machines(Test Method F732), total joint
4、 simulation systems (Guides F1714 and F1715), abrasion testing, methods for producingparticulates, such as shatter boxes or pulverizors,pulverizers, commercially available particles, and particles harvested from tissuesin animal or clinical studies.1.3 The debris may include metallic, polymeric, cer
5、amic, or any combination of these.1.4 The digestion procedures to be used and issues of sterilization of retrieved particles are not the subject of this practice.1.5 A classification scheme for description of particle morphology is included in Appendix X3Appendix X31.6 The values stated in SI units
6、are to be regarded as standard. No other units of measurement are included in this standard.1.7 As a precautionary measure, removed debris from implant tissues should be sterilized or minimally disinfected by anappropriate means that does not adversely affect the particulate material.1.8 As a precau
7、tionary measure, removed debris from implant tissues should be sterilized or minimally disinfected by anappropriate means that does not adversely affect the particulate material.This standard does not purport to address all of the safetyconcerns, if any, associated with its use. It is the responsibi
8、lity of the user of this standard to establish appropriate safety and healthpractices and determine the applicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2C242 Terminology of Ceramic Whitewares and Related ProductsC678 Test Method for Determination of Par
9、ticle Size Distribution of Alumina or Quartz Using Centrifugal Sedimentation(Withdrawn 1995)3E11 Specification for Woven Wire Test Sieve Cloth and Test SievesE161 Specification for Precision Electroformed SievesE766 Practice for Calibrating the Magnification of a Scanning Electron MicroscopeE1617 Pr
10、actice for Reporting Particle Size Characterization DataF561 Practice for Retrieval and Analysis of Medical Devices, and Associated Tissues and FluidsF660 Practice for Comparing Particle Size in the Use of Alternative Types of Particle CountersF661 Practice for Particle Count and Size Distribution M
11、easurement in Batch Samples for Filter Evaluation Using an OpticalParticle Counter (Discontinued 2000) (Withdrawn 2000)3F662 Test Method for Measurement of Particle Count and Size Distribution in Batch Samples for Filter Evaluation Using anElectrical Resistance Particle Counter (Discontinued 2002) (
12、Withdrawn 2002)3F732 Test Method for Wear Testing of Polymeric Materials Used in Total Joint Prostheses1 This practice is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of Subcommittee F04.16on Biocompatibility Test Methods
13、.Current edition approved June 1, 2010Oct. 1, 2016. Published September 2010October 2016. Originally approved in 1998. Last previous edition approved in 20052010as F1877 05 (2010).1. DOI: 10.1520/F1877-05R10. 10.1520/F1877-16.2 For referencedASTM standards, visit theASTM website, www.astm.org, or co
14、ntactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standardsstandards Document Summary page on the ASTM website.3 The last approved version of this historical standard is referenced on www.astm.org.This document is not an ASTM standard an
15、d is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only
16、the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1F1714 Guide for Gravime
17、tric Wear Assessment of Prosthetic Hip Designs in Simulator DevicesF1715 Guide for Wear Assessment of Prosthetic Knee Designs in Simulator Devices (Withdrawn 2006)33. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 agglomerate, na jumbled mass or collection of two or more particl
18、es or aggregates, or a combination thereof, heldtogether by relatively weak cohesive forces caused by weak chemical bonding or an electrostatic surface charge generated byhandling or processing.3.1.2 aggregate, na dense mass of particles held together by strong intermolecular or atomic cohesive forc
19、es that is stabletowith normal mixing techniques, including high-speed stirring and ultrasonics.3.1.3 flocculate, na group of two or more attached particles held together by physical forces, such as surface tension,adsorption, or similar forces.3.1.4 aspect ratio (AR), na ratio of the major to the m
20、inor diameter of a particle, which can be used when the major axis doesnot cross a particle outline (see 11.3.3).3.1.5 elongation (E), nratio of the particle length to the average particle width (see 11.3.4).3.1.6 equivalent circle diameter (ECD), na measure of the size of a particle (see 11.3.2 and
21、 Appendix X1).3.1.7 Feret diameter, nthe mean value of the distance between pairs of parallel tangents to a projected outline of a particle.3.1.7 flocculate, na group of two or more attached particles held together by physical forces, such as surface tension,adsorption, or similar forces.3.1.8 form
22、factor (FF), na dimensionless number relating area and perimeter of a particle, as determined in 11.3.6.3.1.9 irregular, adjreferring to a particle that cannot be described as round or spherical. A set of standard nomenclature andreference figures are given in Appendix X2.3.1.10 particle, nthe small
23、est discrete unit detectable as determined in test methods.Ananoparticle has at least one dimensionless than 100 nm.3.1.11 particle breadth, ndistance between touch points of the shortest Feret pair, orthogonal to length.3.1.12 particle length, ndistance between the touch points of maximum Feret pai
24、r. This value will be greater than or equalto the maximum Feret diameter.3.1.13 rectangular, adjreferring to a particle that approximates a square or rectangle in shape.3.1.14 roundness (R), na measure of how closely an object represents a circle as determined in 11.3.5.3.1.15 spherical, adjreferrin
25、g to a particle with a generally spherical shape that appears round in a photograph.4. Summary of Practice4.1 Particles produced by implant wear in vivo in animal or clinical studies are harvested from tissues after digestion utilizingmethods, such as those in Practice F561. Particles generated in v
26、itro, or obtained from commercial sources, are used as received,or after digestion, if they were generated in protein solutions, and further separation if there are signs of aggregation. A two levelanalysis is provided. For routine analysis, the particles are characterized by the terms of morphology
27、 and by size using Feretdiameters. For more detailed studies, several methods are described that may be utilized for numerically characterizing theirdimensions, size distribution, and number.number are described.5. Significance and Use5.1 The biological response to materials in the form of small par
28、ticles, as from wear debris, often is significantly different fromthat to the same materials as larger implant components. The size and shape (morphology) of the particles may have a major effecton the biological response; therefore, this practice provides a standardized nomenclature for describing
29、particles. Such a unifiednomenclature will be of value in interpretation of biological tests of responses to particles, in that it will facilitate separation ofbiological responses associated with shape from those associated with the chemical composition of debris.5.2 The quantity, size, and morphol
30、ogy of particles released as wear debris from implants in vivo may produce an adversebiological response which will affect the long term survival of the device. Characterization of such debris will provide valuableinformation regarding the effectiveness of device designs or methods of processing com
31、ponents and the mechanisms of wear.5.3 The morphology of particles produced in laboratory tests of wear and abrasion often is affected by the test conditions, suchas the magnitude and rate of load application, device configuration, and test environment. Comparison of the morphology and sizeof partic
32、les produced in vitro with those produced in vivo will provide valuable information regarding the degree to which themethod simulates the in vivo condition being modeled.F1877 1626. Interferences6.1 Particles may form aggregates or agglomerates during preparation and storage. These wouldcould result
33、 in an increase inmeasured particle size and decrease in particle number. It is essential that care be taken to resuspend particles prior to analysis andto note any effects of the dispersant used.6.2 Debris from wear tests or harvested from tissues may contain a mixture of materials. Care should be
34、taken to separate theparticles and methods utilized to determine the chemical composition of the particles.6.3 Many automated particle counters operate on the assumption that the particles are spherical. These methods may not beappropriate for nonspherical debris. Additional methods should be used t
35、o verify size using methods that take aspect ratio intoconsideration, for example, SEM or TEM image analysis.7. Apparatus7.1 Scanning Electron Microscope (SEM) (see Practice E766):7.1.1 Standard SEM equipment can be utilized for many studies. In special instances, such as with polymeric particles, a
36、 lowacceleration voltage (1-2 kV) machine with a high brightness electron source, such as a field emission tip, may be utilized.7.1.2 Elemental analysis may be accomplished with an energy dispersive spectrometer (EDS) for energy dispersive X-rayanalysis (EDXA).7.2 Transmission Electron Microscopy (T
37、EM):7.2.1 TEM equipment can be used for the analysis of nanoparticles, although SEM with a field emission tip has also beensuccessfully used to characterize particles as small as 50 to 100 nm.7.2.2 Elemental analysis may be accomplished with an energy dispersive spectrometer (EDS) for energy dispers
38、ive X-rayanalysis (EDXA).7.3 Optical MicroscopeAn optical microscope operating in the transmission mode may be utilized. Dark field illuminationmay enhance visualization of some particles. Polarized light will facilitate identification of semicrystalline polymeric materials.7.4 Automatic Particle Co
39、unters (see Practice F660):7.4.1 Image AnalyzerThis instrument counts particles by size as those particles lie on a microscope slide.7.4.2 Optical CounterThis instrument measures the area of a shadow cast by a particle as it passes a window. From this areathe instrument reports the diameter of a cir
40、cle of equal area.7.4.3 Electrical Resistance CounterThis instrument measures the volume of an individual particle. From that volume theinstrument reports the diameter of a sphere of equal volume (see Test Methods C678).8. Reagents8.1 Particle-Free (0.2 m Filtered) Deionized Water, for nonpolymeric
41、particles.8.2 Particle-Free (0.2 m Filtered) Methanol or Ethanol, for polymeric or mixed debris.8.3 Ultra-Cleaning Reagent, for apparatus or labware cleaning.9. Specimen Preparation9.1 Specimens from explanted tissues from animal or clinical studies may need to be harvested and digested using method
42、s,such as those described in Practice F561.9.2 Particles from in vitro cell culture tests also may need to be digested and harvested.9.3 Centrifugation of particles from wear may be considered, if necessary, at 400 g for 10 min, or at 16,000 g for 15 min. fornanoparticles, and resuspended in water w
43、ater, ethanol, or methanol. Resuspended particles may be filtered in accordance withPractice F561 prior to examination by SEM.SEM or TEM, although it should be recognized that filtration can lead to a loss ofnanoparticles and/or the agglomeration of particles.10. Particle Imaging by Light Light, Sca
44、nning, or ScanningTransmission Electron Microscopy10.1 Images may either be captured electronically or photographically for subsequent analysis.10.2 For the characterization and measurements to be accurate, it is essential that the particles be imaged at the largestmagnification as possible. The mag
45、nifications in Table 1 are recommended.10.3 For particle size distribution measurements, divide each of the size ranges specified in Table 1, into 10 bins.11. Particle Characterization11.1 Particle Shape (Morphology)Refer to the photographs and classify the morphology of the particles using thenomen
46、clature in Appendix X2.11.2 Routine Particle Size Determination Using Feret Diameters:F1877 16311.2.1 The use of multiple Feret diameters especially is especially useful for spherical and rectangular particles.11.2.2 Determine the particle size and aspect ratio as the mean of two Feret diameters.11.
47、2.3 Calculate the particle size distribution based on the volume of solution used and the size of the filters.11.3 Detailed Particle Shape Analysis for Irregular Shaped Particles:11.3.1 Five particle dimensional measurements are provided using examples shown in Appendix X1. One is a measure ofpartic
48、le size while the other four are shape descriptors.11.3.2 The Equivalent Circle Diameter (ECD) as a Measure of Particle Size:11.3.2.1 The ECD is defined as the diameter of a circle with an area equivalent to the area (A) of the particle and has the unitsof length:ECD54*A/pi!12 (1)11.3.3 The Aspect R
49、atio (AR) is a Common Measure of Shape:11.3.3.1 The AR is the ratio of the major diameter (dmax) to the minor diameter (dmin). The major diameter is the longest straightline that can be drawn between any two points on the outline. The minor diameter is the longest line perpendicular to the majordiameter:AR5dmax/dmin (2)11.3.4 The elongation (E), is similar to the AR except it is more suited for the measurement of much longer particles, especiallyfibrilar particles, where the major axis line does not stay within the particle boundaries. Refer to particle
