1.1 Infrared (IR) spectroscopy is a valuable method of fiber polymer identification and comparison in forensic examinations. The use of IR microscopes, coupled with Fourier transform infrared (FTIR) spectrometers, has greatly simplified the IR analysis of single fibers, thus making the technique feasible for routine use in the forensic laboratory. This guide provides basic recommendations and information about IR spectrometers and accessories, with an emphasis on sampling techniques specific to fiber examinations. The particular method(s) employed by each examiner or laboratory will depend upon available equipment, examiner training, sample suitability, and sample size.
1.2 This guide is intended for examiners with a basic knowledge of the theory and practice of IR spectroscopy, as well as experience in the handling and forensic examination of fibers. In addition, this guide is to be used in conjunction with a broader analytical scheme.
1.3 If polymer identification is not readily apparent from optical data alone, an additional method of analysis, such as microchemical tests, melting point, IR spectroscopy, Raman spectroscopy, or pyrolysis gas chromatography, should be used. An advantage of IR spectroscopy is that the instrumentation is readily available in most forensic laboratories and the technique is minimally destructive.
1.4 Units—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 standard is intended for use by competent forensic science practitioners with the requisite formal education, discipline-specific training (see Practice E2917), and demonstrated proficiency to perform forensic casework.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.7 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.
ASTM E2224-23a Referenced Document
ASTM D123 Standard Terminology Relating to Textiles*, 2023-09-14 Update
ASTM E131 Standard Definitions of Terms and Symbols Relating to Molecular Spectroscopy
ASTM E1421 Standard Practice for Describing and Measuring Performance of Fourier Transform Mid-Infrared (FT-MIR) Spectrometers: Level Zero and Level One Tests
ASTM E1459 Standard Guide for Physical Evidence Labeling and Related Documentation
ASTM E1492 Standard Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
ASTM E2228 Standard Guide for Microscopical Examination of Textile Fibers
ASTM E2917 Standard Practice for Forensic Science Practitioner Training, Continuing Education, and Professional Development Programs*, 2024-02-01 Update
ASTM E620 Standard Practice for Reporting Opinions of Technical Experts
ISO/IEC 17025 General requirements for the competence of testing and calibration laboratories [Standard in French]
ASTM E2224-23a history
2023ASTM E2224-23ae1 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2023ASTM E2224-23a Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2023ASTM E2224-23 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2022ASTM E2224-22 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2019ASTM E2224-19 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2018ASTM E2224-18 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2010ASTM E2224-10 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
2002ASTM E2224-02 Standard Guide for Forensic Analysis of Fibers by Infrared Spectroscopy