ASTM E3296-22

Standard Guide for Using Pyrolysis Gas Chromatography and Pyrolysis Gas Chromatography-Mass Spectrometry in Forensic Polymer Examinations

SIGNIFICANCE AND USE
4.1 This guide provides guidance in the selection of appropriate sample preparation methods and instrumental parameters for the analysis, comparison, or identification of various polymeric materials by PGC and PGC/MS.  
4.1.1 PGC/MS can differentiate between classes of fibers (for example, acrylic, polyester, nylon) and within classes of fibers (for example, acrylics) (1-3).5  
4.1.2 Paint binders are differentiated based upon the variety of monomers used in paint formulations which could be difficult to identify by other analytical techniques. In addition, some additives can be detected or identified.  
4.1.3 Differentiation can be achieved by the separation and identification of organic components in the adhesive portion of tapes (4, 5) and in the backings of electrical tapes (6).  
4.1.4 PGC/MS can provide additional discrimination for other types of polymers such as automotive lenses, automotive body fillers, cosmetics, plastics, and rubbers (7-9).  
4.2 Pyrolysis breaks a large molecule into many smaller molecules in a reproducible fashion through the breaking of bonds by means of the application of thermal energy. Analytical pyrolysis is used to provide chemical information on organic-containing solids that cannot be dissolved or otherwise introduced into a chromatographic system. It is also used to analyze and compare solvents bound in a solid material (such as tape adhesives) (10). When analyzed using a separation technique such as gas chromatography, the smaller molecules produced through the action of pyrolysis form a pattern of separated fragments. Mass and structural information indicative of the original molecule are also available when a mass spectral detector is used.  
4.3 Although a destructive method, and therefore often placed at the end of an analytical scheme, the pyrograms produced from different polymer compositions form characteristic patterns that are useful for both identification of polymer type and comparisons between samples (4, 6...
SCOPE
1.1 This guide covers information and recommendations for the selection and application of various PGC and PGC/MS procedures and methods in the forensic examination of polymeric materials (for example, fibers, paint, tape). PGC and PGC/MS methods are used for the identification and comparison of the organic components of these materials. Refer to Practice D3452 for further information on the preparation of the pyrolysis system for polymeric analyses.  
1.2 This guide is to be used in conjunction with a broader analytical scheme such as Guides E1610 or E3260, or the SWGMAT Forensic Fiber Examination Guidelines.  
1.3 This standard is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practices E2917, E3233, E3234), and demonstrated proficiency to perform forensic casework.  
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Dec-2021
• ICS: 07.140 - Forensic science
• ICS: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: E30 - Forensic Sciences
• Drafting Committee: E30.01 - Criminalistics

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E3296 − 22 An American National Standard
Standard Guide for
Using Pyrolysis Gas Chromatography and Pyrolysis Gas
Chromatography-Mass Spectrometry in Forensic Polymer
1
Examinations
This standard is issued under the fixed designation E3296; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The forensic analysis of polymers (for example, fibers, paints and coatings, tapes and adhesives)
using pyrolysis gas-chromatography (PGC) or pyrolysis gas-chromatography/mass spectrometry
(PGC/MS) is a destructive technique that provides detailed organic chemical information about such
samples. This information augments that obtained from other analytical techniques such as Fourier
transform infrared spectroscopy (FTIR), polarized light microscopy (PLM), scanning electron
microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), and X-ray fluorescence spectroscopy
(XRF).
1. Scope Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
1.1 Thisguidecoversinformationandrecommendationsfor
Barriers to Trade (TBT) Committee.
the selection and application of various PGC and PGC/MS
procedures and methods in the forensic examination of poly-
2. Referenced Documents
meric materials (for example, fibers, paint, tape). PGC and
2
2.1 ASTM Standards:
PGC/MS methods are used for the identification and compari-
D16 TerminologyforPaint,RelatedCoatings,Materials,and
son of the organic components of these materials. Refer to
Applications
Practice D3452 for further information on the preparation of
D123 Terminology Relating to Textiles
the pyrolysis system for polymeric analyses.
D3452 Practice for Rubber—Identification by Pyrolysis-Gas
1.2 This guide is to be used in conjunction with a broader
Chromatography
analytical scheme such as Guides E1610 or E3260,orthe
E355 Practice for Gas ChromatographyTerms and Relation-
SWGMAT Forensic Fiber Examination Guidelines.
ships
1.3 This standard is intended for use by competent forensic
E1492 Practice for Receiving, Documenting, Storing, and
science practitioners with the requisite formal education,
Retrieving Evidence in a Forensic Science Laboratory
discipline-specific training (see Practices E2917, E3233,
E1610 Guide for Forensic Paint Analysis and Comparison
E3234), and demonstrated proficiency to perform forensic
E1732 Terminology Relating to Forensic Science
casework.
E2917 Practice for Forensic Science Practitioner Training,
Continuing Education, and Professional Development
1.4 The values stated in SI units are to be regarded as
Programs
standard. No other units of measurement are included in this
E3233 PracticeforForensicTapeAnalysisTrainingProgram
standard.
E3234 Practice for Forensic Paint Analysis Training Pro-
1.5 This international standard was developed in accor-
gram
dance with internationally recognized principles on standard-
E3260 Guide for Forensic Examination and Comparison of
ization established in the Decision on Principles for the
1 2
This guide is under the jurisdiction of ASTM Committee E30 on Forensic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Current edition approved Jan. 1, 2022. Published February 2022. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
E3296-22. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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E3296 − 22
Pressure Sensitive Tapes 4.2 Pyrolysis breaks a large molecule into many smaller
2.2 Other Documents: molecules in a reproducible fashion through the breaking of
ISO/IEC 17025 General requirements for the competence of bonds by means of the application of thermal energy. Analyti-
3
testing and calibration laboratories cal pyrolysis is used to provide chemical information on
4
SWGMAT Forensic Fiber Examination Guidelines organic-containing solids that cannot be dissolved or otherwise
4
SWGMAT Trace Evidence Quality Assurance Guidelines introduced into a chromatographic system. It is also used to
4
SWGMAT Trace Evidence Recovery Guidelines analyze and compare solvents bound in a solid material (such
as tape adhesives) (10). When analyzed using a
...