1、Designation: E2998 16Standard Practice forCharacterization and Classification of Smokeless Powder1This standard is issued under the fixed designation E2998; 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 describes procedures for characterizationand analysis of smokeless powders recovered from explosivesincidents (1, 2),2
3、materials or objects containing gunshotresidue (3) when visible grains are present, or bulk samples ofpowder.1.2 Smokeless powder is characterized by shape, color,texture, manufacturing toolmarks, markers, dimensionalmeasurements, and chemical composition (4-6).1.3 Smokeless powder is an energetic m
4、aterial classified asa low explosive or propellant. Smokeless powder can befurther classified as single-base, double-base, or triple-base.1.4 Analysis of post-blast debris and items containing gun-shot residue when visible grains of smokeless powder are notpresent is beyond the scope of this practic
5、e.1.5 This practice will provide guidelines for the analysis oforganic components of smokeless powders using variousinstrumental techniques, such as gas chromatography-massspectrometry, liquid chromatography, and Fourier transforminfrared spectroscopy.1.6 The values stated in SI units are to be rega
6、rded asstandard. No other units of measurement are included in thisstandard.1.7 This standard involves handling of low explosives andpotentially other energetic materials. It is strongly suggestedthat an analyst be trained in the storage and safe handling ofenergetic materials and be familiar with t
7、he properties andhazards of explosives.1.8 This standard cannot replace knowledge, skill, or abilityacquired through appropriate education, training, and experi-ence and should be used in conjunction with sound profes-sional judgment.1.9 This standard does not purport to address all of thesafety con
8、cerns, 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:3E620 Practice for Reporting Opinions o
9、f Scientific or Tech-nical ExpertsE1492 Practice for Receiving, Documenting, Storing, andRetrieving Evidence in a Forensic Science LaboratoryE1618 Test Method for Ignitable Liquid Residues in Extractsfrom Fire Debris Samples by Gas Chromatography-MassSpectrometry3. Terminology3.1 Definitions of Term
10、s Specific to This Standard:3.1.1 ball powders, na class of smokeless powders pro-duced by a process where the final grain morphologies arespherical, flattened-ball, or flake.3.1.2 double-base, npropellant containing nitrocelluloseand nitroglycerin.3.1.3 deterrent, na compound to slow the burning ra
11、te ofa powder.3.1.4 energetic, nan explosive compound used to enhancethe burning rate of a powder.3.1.5 extruded powders, na class of smokeless powdersproduced by an extrusion process where the final grainmorphologies are disc or cylinder.3.1.6 grain, nan individual particle of smokeless powder.3.1.
12、7 marker, na colored grain of smokeless powder toassist in the visual identification of a bulk reloading smokelesspowder.3.1.8 perforation, na hole in a disc powder or one or moreholes running through the length of a cylinder powder createdduring the manufacturing process in extruded powders.3.1.9 s
13、ingle-base, npropellant containing nitrocellulose asthe major energetic material.1This practice is under the jurisdiction of ASTM Committee E30 on ForensicSciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.Current edition approved Oct. 1, 2016. Published October 2016.
14、 DOI: 10.1520/E2998-16.2The boldface numbers in parentheses refer to a list of references at the end ofthis standard.3For 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
15、 the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.10 smokeless powder, na propellant and low explosivecomposed of nitrocellulose and other organic and inorganiccompounds.3.1.11
16、 stabilizer, na compound to prevent or slow downself-decomposition.3.1.12 triple-base, npropellant containing nitrocellulose,nitroglycerin, and nitroguanidine.4. Summary of Practice4.1 The physical properties of smokeless powder grains arerecorded by visual examination using a stereo lightmicroscope
17、, micrometer, manual measuring device, digitalmeasurement and recording device, or camera.4.2 The significant physical properties of smokeless pow-ders to measure are diameter, length, and thickness. Thesignificant physical properties to record are shape, color,perforations, texture, striations (man
18、ufacturing toolmarks), andmarkers.4.3 Techniques are described for the extraction of organiccomponents of smokeless powders for instrumental analysis.4.4 The chemical properties and composition of smokelesspowders can be determined by a combination of techniqueswhich may include burn testing, gas ch
19、romatography, liquidchromatography, capillary electrophoresis, mass spectrometry,and Fourier transform infrared spectroscopy (7-12).5. Significance and Use5.1 This practice establishes guidelines for the characteriza-tion of smokeless powder which can be used as an explosivefor improvised explosive
20、devices or as a propellant, such as forsmall arms ammunition and for military ordnance.5.2 This practice establishes the minimum criteria necessaryto classify smokeless powders.5.3 The morphology of smokeless powder is a distinctcharacteristic used for classification and identification pur-poses.5.4
21、 The identification of a questioned sample as smokelesspowder (that is, it is a propellant or low explosive) does notrequire the identification of chemical components of a smoke-less powder other than nitrocellulose.5.5 Identification of organic compounds associated withsmokeless powders is a requir
22、ement to classify a smokelesspowder sample as single-base, double-base, or triple-base.5.6 Additional analytical techniques may be available thatare not mentioned within this document that are acceptable forthe characterization and analysis of smokeless powders.5.7 The requirements to associate a qu
23、estioned smokelesspowder to a unique smokeless powder product by brand nameor intercomparison of two or more questioned powders arebeyond the scope of this document (13-15).5.8 The identification of smokeless powder residue in theabsence of whole or partial grains is beyond the scope of thisdocument
24、.6. Apparatus6.1 Stereo light microscope with an appropriate light source.6.2 Magnifying lamp with at least 3 diopter magnification.6.3 Gas chromatograph-mass spectrometerA gas chro-matograph (GC) capable of using capillary columns and beinginterfaced to a mass spectrometer (MS) operating in electro
25、nionization (EI) mode.6.4 Fourier transform infrared spectrometer (FTIR)AnFTIR capable of acquiring spectra in the mid-infrared region.6.4.1 Micro-FTIR.6.5 GC with flame ionization detector (FID), thermal energyanalyzer (TEA), or electron capture detector (ECD).6.6 Capillary electrophoresis (CE) sys
26、tem.6.7 Liquid chromatograph (LC).6.8 LC-MS.6.9 Digital imaging system and computer.6.10 Digital camera that can attach to or be used inconjunction with a stereo light microscope.7. Chemicals, Reagents, and Reference Materials7.1 Purity of ReagentsReagent grade or better chemicalsshould be used in a
27、ll tests. Unless otherwise indicated, it isintended that all reagents conform to the specifications of theCommittee on Analytical Reagents of the American ChemicalSociety where such specifications are available.4Other gradesmay be used, provided it is first ascertained that the reagent isof sufficie
28、ntly high purity to permit its use without lesseningthe accuracy of the determination.7.2 SolventsMethylene chloride and acetone (ACS re-agent grade or better) or other appropriate solvents of equalquality are acceptable.7.3 Test MixtureThe test mixture should consist ofnitroglycerin, diphenylamine,
29、 ethyl centralite, and 2,6-dinitrotoluene. The final test solution is prepared by dilutingthe above mixture such that the concentration of each compo-nent is no greater than 0.005 % weight/volume (0.05 mg/mL)in the chosen solvent (see 7.2). Additional compounds com-monly found in smokeless powders m
30、ay also be included in thetest mixture, such as methyl centralite, 2,4-dinitrotoluene,2-nitrodiphenylamine, 4-nitrodiphenylamine, diethylphthalate,and dibutylphthalate.7.3.1 Appropriate concentrations of individual referencematerials or standards of these compounds may be used inaddition to or inste
31、ad of a test mixture.NOTE 1In addition to component identification, appropriate concen-trations of the test mixture (or standards) can be used to evaluate overallinstrument performance or sensitivity (for example, column resolution,instrument detection limits).4Reagent Chemicals, American Chemical S
32、ociety Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmace
33、utical Convention, Inc. (USPC), Rockville,MD.E2998 1627.4 Internal StandardAn appropriate internal standard(for example, undecane, decane) may be used in the extractionsolvent for GC and LC analyses.7.5 Reference Smokeless PowdersReference smokelesspowders can be obtained as bulk reloading powders f
34、romcommercial and retail sources or directly from the distributoror manufacturer.7.5.1 Reference smokeless powders may be analyzed aspositive controls or comparison samples following the sameprocedure for questioned samples.7.6 GC Carrier GasHelium or hydrogen of purity 99.995% or higher.7.7 Deioniz
35、ed Water18 megohms or better.7.8 Polystyrene Film Standard.7.9 FTIR SuppliesSalt plates, mortar and pestle, pelletpress.7.10 Glassware and Other SuppliesDisposable test tubes,pipettes, beakers, autosampler vials, weigh boats, weigh paper,watch glasses.8. Sample Handling8.1 Observe the appropriate pr
36、ocedures for handling anddocumentation of all submitted samples as described in Prac-tice E1492.8.2 Open and examine the item in order to determine that itis consistent with its description.8.3 If the item is suspected of containing residues of anignitable liquid, perform an ignitable liquid extract
37、ion andanalysis on the item (or sample of bulk powder) prior tocontinuing with the analysis for smokeless powder. Refer toTest Method E1618.8.3.1 WarningHeadspace extraction techniques for ignit-able liquids should be performed at temperatures below 40Con specimens.8.4 On a clean surface, conduct a
38、visual examination of theitem.8.4.1 An examination lamp with an optical magnifier or astereo light microscope can be used to enhance the detection ofsmall-grain powders.8.5 Photograph observed grains in situ on debris samples (ifpossible and probative).8.6 Physically remove a representative sample o
39、f suspectedsmokeless powder from debris samples and transfer to asuitable sample holder.8.7 For bulk powders, a representative sample should beseparated from bulk powders for analysis as a safety consid-eration. Store the remaining bulk powders per laboratorypolicy and local regulations.8.8 Separate
40、 smokeless powder grains from any other ma-terials in the sample, using a stereo light microscope ifnecessary.8.8.1 Other energetic materials, such as black powder andflash powder, are sometimes combined with smokeless powderin explosives casework.8.9 When two or more smokeless powders are obviously
41、present, separate them into similar morphological groups andexamine separately if necessary.9. Analysis Plan for the Characterization of SmokelessPowders9.1 Characterization of a smokeless powder involves iden-tifying the unique physical characteristics of the powder alongwith chemical analysis (4-6
42、) to identify the nitrocellulose(which is common to all smokeless powders) and other organiccomponents present in propellants.9.2 Analysis Plan Summary:9.2.1 Visual examination and recording of physical charac-teristics9.2.2 Extractions and analysis of organic components9.2.3 Burn test (if sufficien
43、t sample is available)9.3 Visual Examination and Recording of Physical Charac-teristics:9.3.1 Use a stereo light microscope if necessary to observeand record the shape, color, markers, perforations, toolmarks,irregular shapes, and any unique physical characteristics.9.3.1.1 If feasible, capture a sc
44、aled image of the powder forcomparison to similar known powders.9.3.2 Record the shape (morphology) of the powder grain:9.3.2.1 Disca flat circular grain (coins), either solid orcontaining a perforation, of varying thickness typically under0.35 mm.9.3.2.2 Cylinder (or rod)a short rod-like grain eith
45、er solidor containing one or more perforations.NOTE 2Most cylinder powders used in small arms ammunition havea single perforation which is often difficult to observe because of thegraphite coating on the grains or from effects caused by the mechanicalcutting of the grain. Large cylindrical powders h
46、aving multiple perfora-tions are characteristic of military propellants.9.3.2.3 Sphere (or ball)a round grain with no flat surfaces.9.3.2.4 Flattened-balla spherical grain that is flattened topand bottom (some extremely flattened) and may exhibit radialstress fractures.9.3.2.5 Flakea flat irregularl
47、y shaped grain usually with arough non-uniform surface.9.3.2.6 Agglomeratemultiple small spherical grains ad-hering together (such as grapes on a vine).9.3.2.7 Lamela thin square or parallelogram grain (madefrom a sheet manufacturing process).9.3.2.8 Irregulara highly modified grain lacking any par-
48、ticular shape with no consistently measurable dimension suchas length or diameter.9.3.3 Coarse dimensional measurements of the diameter,length, or width of powder grains in the specimen can bedetermined through a side by side comparison to referencesmokeless powders of similar morphology or by use o
49、fmeasurement tools.9.3.3.1 Precise measurement of diameter, length, or thick-ness is not required for class identification of smokelesspowders.9.3.4 A specimen containing powder of one or more differ-ent types of morphology may be further differentiated andE2998 163treated as separate specimens based on differing physicalcharacteristics noted in the microscopical analysis.9.3.4.1 Further differentiation is not required for class iden-tification of smokeless powder but may be useful for futureintercomparison between two or more powders or associatin
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