ASTM E2227-13

Standard Guide for Forensic Examination of Non-Reactive Dyes in Textile Fibers by Thin-Layer Chromatography (Withdrawn 2022)

SIGNIFICANCE AND USE
5.1 Forensic analysis of fiber colorants using TLC should be considered for single fiber comparisons only when it is not possible to discriminate between the fibers of interest using other techniques, such as comparison microscopy (brightfield and fluorescence) and microspectrophotometry in the visible range.  
5.2 The extraction procedures carried out prior to TLC analysis can provide useful information about dye classification. TLC can provide useful qualitative information about dye components. Similar colors made up of different dye components can be differentiated using this technique. The application of TLC may serve to discriminate between fibers, or it may confirm their similarity.  
5.3 TLC may be prohibitively difficult or undesirable in some circumstances. Short lengths of fibers or pale colored fibers may not have an adequate concentration of colorant present to be examined. Dye extraction from some fibers may be impossible. The desire to preserve evidence for possible analysis by another examiner may preclude removing the color for analysis.  
5.4 Dye from the known material should first be characterized and eluent systems evaluated to achieve optimum separation of the extract. Dye is then extracted from single known and questioned fibers, using an equivalent amount of material.  
5.5 The development of each individual TLC plate will show some variability as a result of the coating and conditioning of the plate, solvent condition, and temperature. It is important to evaluate the performance of each TLC plate by spotting known materials along with the questioned samples. See Ref (1).3  
5.6 Examples for the preparation of Standard dye mixtures are given in Appendix X1.
SCOPE
1.1 Metameric coloration of fibers can be detected using UV/visible spectrophotometry. If spectrophotometry is restricted to the visible spectral range only, differences in dye components may remain undetected. One method of detecting additional components is to use thin-layer chromatography (TLC). TLC is an inexpensive, simple, well-documented technique that, under certain conditions, can be used to complement the use of visible spectroscopy in comparisons of fiber colorants. The principle of the method is that the dye components are separated by their differential migration caused by a mobile phase flowing through a porous, adsorptive medium.  
1.2 This standard does not replace knowledge, skill, ability, experience, education, or training and should be used in conjunction with professional judgment.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.4 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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Aug-2013
• 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)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: E2227 − 13
Standard Guide for
Forensic Examination of Non-Reactive Dyes in Textile
1
Fibers by Thin-Layer Chromatography
This standard is issued under the fixed designation E2227; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E2228Guide for Microscopical Examination of Textile Fi-
bers
1.1 Metameric coloration of fibers can be detected using
UV/visible spectrophotometry. If spectrophotometry is re-
3. Terminology
stricted to the visible spectral range only, differences in dye
3.1 Definitions of Terms Specific to This Standard:
components may remain undetected. One method of detecting
3.1.1 activation—the heating of the adsorbent layer on a
additional components is to use thin-layer chromatography
plate to dry out the moisture and maximize its adsorptive
(TLC). TLC is an inexpensive, simple, well-documented tech-
power.
nique that, under certain conditions, can be used to comple-
3.1.2 adsorbent—the stationary phase for adsorption TLC.
ment the use of visible spectroscopy in comparisons of fiber
colorants. The principle of the method is that the dye compo-
3.1.3 adsorption—the attraction between the surface atoms
nents are separated by their differential migration caused by a
of a solid and an external molecule by intermolecular forces.
mobile phase flowing through a porous, adsorptive medium.
3.1.4 chamber—a glass chamber in which TLC develop-
1.2 This standard does not replace knowledge, skill, ability,
ment is carried out.
experience, education, or training and should be used in
3.1.5 chromatography—a method of analysis in which sub-
conjunction with professional judgment.
stancesareseparatedbytheirdifferentialmigrationinamobile
1.3 The values stated in SI units are to be regarded as phase flowing through or past a stationary phase.
standard. No other units of measurement are included in this
3.1.6 development—the movement of the mobile phase
standard.
through the adsorbent layer to form a chromatogram.
1.4 This standard does not purport to address all of the
3.1.7 dye extraction—theremovalofthedyefromafiberby
safety concerns, if any, associated with its use. It is the
incubating it in an appropriate solvent.
responsibility of the user of this standard to establish appro-
3.1.8 eluent—the solvent mixture that acts as the mobile
priate safety and health practices and determine the applica-
phase in TLC.
bility of regulatory limitations prior to use.
3.1.9 metameric pair—two colors that appear the same
under one illumination, but different under other illumination.
2. Referenced Documents
2
3.1.10 mobile phase—the moving liquid phase used for
2.1 ASTM Standards:
development.
E1459Guide for Physical Evidence Labeling and Related
Documentation
3.1.11 normal-phase chromatogram—adsorption in which
E1492Practice for Receiving, Documenting, Storing, and the stationary phase is polar in relation to the mobile phase.
Retrieving Evidence in a Forensic Science Laboratory
3.1.12 origin—the location of the applied sample or the
E2224Guide for Forensic Analysis of Fibers by Infrared
starting point for the chromatographic development of the
Spectroscopy
applied sample.
3.1.13 resolution—theabilitytovisuallyseparatetwospots.
3.1.14 retardation factor (Rf)—the ratio of the distance
1
This guide is under the jurisdiction of ASTM Committee E30 on Forensic
Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics. traveled by the solute spot’s center divided by the distance
Current edition approved Sept. 1, 2013. Published September 2013. Originally
traveled by the solvent front, both measured from the origin.
approved in 2002. Last previous edition approved in 2008 as E2227–02 (2008).
3.1.15 saturation chamber—equilibration with mobile
DOI: 10.1520/E2227-13.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
phase solvent vapor prior to chromatography.
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3.1.16 solute—in TLC, a mixture of components to be
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. separated.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E2227 − 13
3.1.17 solvent front—the final point reached by the mobile be impossible. The desire to preserve evidence for possible
phase as it flows up or across the TLC plate during develop- analysisbyanotherexaminermayprecluderemovingthecolor
ment of the chromatogram. for analysis.
3.1.18 spot—a round zon
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E2227 − 02 (Reapproved 2008) E2227 − 13
Standard Guide for
Forensic Examination of Non-Reactive Dyes in Textile
1
Fibers by Thin-Layer Chromatography
This standard is issued under the fixed designation E2227; 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.
1. Scope
1.1 Metameric coloration of fibers can be detected using UV/visible spectrophotometry. If spectrophotometry is restricted to the
visible spectral range only, differences in dye components may remain undetected. One method of detecting additional components
is to use thin-layer chromatography (TLC). TLC is an inexpensive, simple, well-documented technique that, under certain
conditions, can be used to complement the use of visible spectroscopy in comparisons of fiber colorants. The principle of the
method is that the dye components are separated by their differential migration caused by a mobile phase flowing through a porous,
adsorptive medium.
1.2 This standard does not replace knowledge, skill, ability, experience, education, or training and should be used in conjunction
with professional judgment.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 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 and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2
2.1 ASTM Standards:
E1459 Guide for Physical Evidence Labeling and Related Documentation
E1492 Practice for Receiving, Documenting, Storing, and Retrieving Evidence in a Forensic Science Laboratory
E2224 Guide for Forensic Analysis of Fibers by Infrared Spectroscopy
E2228 Guide for Microscopical Examination of Textile Fibers
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 activation—the heating of the adsorbent layer on a plate to dry out the moisture and maximize its adsorptive power.
3.1.2 adsorbent—the stationary phase for adsorption TLC.
3.1.3 adsorption—the attraction between the surface atoms of a solid and an external molecule by intermolecular forces.
3.1.4 chamber—a glass chamber in which TLC development is carried out.
3.1.5 chromatography—a method of analysis in which substances are separated by their differential migration in a mobile phase
flowing through or past a stationary phase.
3.1.6 development—the movement of the mobile phase through the adsorbent layer to form a chromatogram.
3.1.7 dye extraction—the removal of the dye from a fiber by incubating it in an appropriate solvent.
3.1.8 eluent—the solvent mixture that acts as the mobile phase in TLC.
3.1.9 metameric pair—two colors that appear the same under one illumination, but different under other illumination.
3.1.10 mobile phase—the moving liquid phase used for development.
1
This guide is under the jurisdiction of ASTM Committee E30 on Forensic Sciences and is the direct responsibility of Subcommittee E30.01 on Criminalistics.
Current edition approved March 15, 2008Sept. 1, 2013. Published July 2008 September 2013. Originally approved in 2002. Last previous edition approved in 20022008
as E2227 – 02.E2227 – 02 (2008). DOI: 10.1520/E2227-02R08.10.1520/E2227-13.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
E2227 − 13
3.1.11 normal-phase chromatogram—adsorption in which the stationary phase is polar in relation to the mobile phase.
3.1.12 origin—the location of the applied sample or the starting point for the chromatographic development of the applied
sample.
3.1.13 resolution—the ability to visually separate two spots.
3.1.14 retardation factor (RF)—(Rf)—the ratio of the distance traveled by the solute spot’s center divided by the distance
traveled by the solvent front, both measured from the origin.
3.1.15 saturation chamber—equilibration with mobile phase solvent va
...