ASTM D2743-68(2010)
(Practice)Standard Practices for Uniformity of Traffic Paint Vehicle Solids by Spectroscopy and Gas Chromatography (Withdrawn 2015)
Standard Practices for Uniformity of Traffic Paint Vehicle Solids by Spectroscopy and Gas Chromatography (Withdrawn 2015)
SIGNIFICANCE AND USE
All of the methods provided involve comparisons between the spectra or chromatograms of the reference and test samples to determine if they show significant differences. It is not possible at this time to establish quantitative limits as a guide to whether a spectral or chromatographic difference is truly significant. Certainly the presence or absence of a moderate or strong peak in the test sample which is not evident in the reference is significant. A persistent difference in the ratios of two peaks of one spectrum as compared to the reference sample is significant. On the whole, some judgment must be exercised in this respect and it is advisable to refer to published data on infrared or gas chromatography in order to establish, where feasible, the possible overall nature of the adulterant or its functional group which might be causing the comparison spectra to differ.
Method A is rapid and the most convenient of the procedures given. It should be utilized first in order to detect nonuniformity of the test sample. Significant spectral differences from that of the reference sample can be taken as an indication of adulteration and in such cases the use of the other methods is not necessary. As a general rule. Method A is sufficient to detect gross or major adulteration of the vehicle solids. However, where Method A shows no significant spectral differences, it cannot be assumed that the test sample is completely acceptable since changes in the type of drying oil, polyol, and certain dibasic acids in alkyd resins, addition of certain aliphatic or nonfunctional hydrocarbon resins, and many minor adulterations may not always show characteristic infrared spectral differences. Therefore, in such cases it is best to proceed to additional tests as given in Methods B and C or else alternatively directly to Method D.
Method B is useful in detecting adulterations that are unsaponifiable or else have an unsaponifiable component that has escaped detection in Method A only b...
SCOPE
1.1 These practices provide general information on the instrumental techniques available for detecting adulteration or nonuniformity of the chemical nature of the vehicle solids in purchased lots of traffic paints by means of the individual or combined use of infrared and ultraviolet spectroscopy and gas chromatography. The procedures given are applicable when traffic paint is selected and purchased on the basis of pre-qualification laboratory or road performance tests, or both, and a reference sample of the original paint so evaluated and selected is retained and compared with test samples representative of subsequent purchased and delivered lots of such paint and which are required to be the same as the original reference sample.
1.2 Although not specifically provided for in these practices, the methods given may also be applied, with appropriate modification, to evaluating the acceptability of traffic paints that have been purchased on the basis of composition specifications. In such cases, application is limited to the vehicle solids as before, as well as the availability of a suitable standard or range of standards representative of the vehicle solids that are acceptable and with which samples of subsequent delivered lots will be compared.
1.3 The techniques provided are wholly adequate for detecting gross adulteration of the vehicle solids where completely different drying oils, resins, or polymers, or combinations of these have been substituted for those originally contained in the reference sample. In cases of lesser adulteration or modification, these methods have been found adequate for detecting vehicle solids, adulterations, or modifications as low as 5 weight % of the vehicle solids.
1.4 These techniques have been developed on the basis of cooperative work with alkyd, chlorinated rubber-alkyd, and poly(vinyl toluene) type paints involving the detection of nonuniformity when such extraneous materials as...
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D2743 − 68 (Reapproved2010)
Standard Practices for
Uniformity of Traffic Paint Vehicle Solids by Spectroscopy
and Gas Chromatography
This standard is issued under the fixed designation D2743; 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 oil, hydrocarbon resin, and chlorinated paraffin have been
added. The procedures given may be, but are not necessarily
1.1 These practices provide general information on the
completely applicable to all other types of vehicle solids or
instrumental techniques available for detecting adulteration or
extraneous additions, or both.
nonuniformity of the chemical nature of the vehicle solids in
purchased lots of traffic paints by means of the individual or 1.5 The methods provided appear in the following order:
combined use of infrared and ultraviolet spectroscopy and gas
Section
Method A—Infrared Spectral Analysis of Total Vehicle Solids 10-12
chromatography. The procedures given are applicable when
Method B—Infrared Spectral Analysis of Unsaponifiable Matter
traffic paint is selected and purchased on the basis of pre-
from Vehicle Solids 13-15
qualification laboratory or road performance tests, or both, and
Method C—Gas Chromatographic Analysis of Oils and Oil Acids
Separated from Vehicle Solids 16-18
a reference sample of the original paint so evaluated and
Method D—Ultraviolet Spectral Analysis of Total Vehicle Solids
selected is retained and compared with test samples represen-
19, 20, and
tative of subsequent purchased and delivered lots of such paint
and which are required to be the same as the original reference
1.6 The values stated in SI units are to be regarded as
sample.
standard. No other units of measurement are included in this
standard.
1.2 Although not specifically provided for in these
practices, the methods given may also be applied, with
1.7 This standard does not purport to address all of the
appropriate modification, to evaluating the acceptability of
safety concerns, if any, associated with its use. It is the
traffic paints that have been purchased on the basis of compo-
responsibility of the user of this standard to establish appro-
sition specifications. In such cases, application is limited to the
priate safety and health practices and determine the applica-
vehicle solids as before, as well as the availability of a suitable
bility of regulatory limitations prior to use.
standard or range of standards representative of the vehicle
solids that are acceptable and with which samples of subse-
2. Referenced Documents
quent delivered lots will be compared.
2.1 ASTM Standards:
1.3 The techniques provided are wholly adequate for detect-
D1259 Test Methods for Nonvolatile Content of Resin
ing gross adulteration of the vehicle solids where completely
Solutions
different drying oils, resins, or polymers, or combinations of
D1397 Test Method for Unsaponifiable Matter in Alkyd
thesehavebeensubstitutedforthoseoriginallycontainedinthe
Resins and Resin Solutions (Withdrawn 2007)
reference sample. In cases of lesser adulteration or
D2245 Test Method for Identification of Oils and Oil Acids
modification, these methods have been found adequate for
in Solvent-Reducible Paints
detecting vehicle solids, adulterations, or modifications as low
D2372 Practice for Separation of Vehicle From Solvent-
as 5 weight % of the vehicle solids.
Reducible Paints
D2621 Test Method for Infrared Identification of Vehicle
1.4 These techniques have been developed on the basis of
Solids From Solvent-Reducible Paints
cooperative work with alkyd, chlorinated rubber-alkyd, and
E105 Practice for Probability Sampling of Materials
poly(vinyl toluene) type paints involving the detection of
E131 Terminology Relating to Molecular Spectroscopy
nonuniformity when such extraneous materials as rosin, fish
1 2
These practices are under jurisdiction of ASTM Committee D01 on Paint and For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Related Coatings, Materials, and Applications and are the direct responsibility of contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Subcommittee D01.44 on Traffic Coatings. Standards volume information, refer to the standard’s Document Summary page on
Current edition approved Dec. 1, 2010. Published December 2010. Originally the ASTM website.
approved in 1968. Last previous edition approved in 2004 as D2743 – 68 (2004) The last approved version of this historical standard is referenced on
DOI: 10.1520/D2743-68R10. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2743 − 68 (2010)
3. Terminology sufficient to detect gross or major adulteration of the vehicle
solids.However,whereMethodAshowsnosignificantspectral
3.1 For definitions of terms and symbols, refer to Terminol-
differences, it cannot be assumed that the test sample is
ogy E131.
completely acceptable since changes in the type of drying oil,
polyol, and certain dibasic acids in alkyd resins, addition of
4. Summary of Methods
certain aliphatic or nonfunctional hydrocarbon resins, and
4.1 Each of the methods given requires both a reference and
many minor adulterations may not always show characteristic
a test sample of traffic paint and a preliminary separation and
infrared spectral differences. Therefore, in such cases it is best
removal of the pigment component in each.
to proceed to additional tests as given in Methods B and C or
4.2 Method A involves infrared spectral analysis of cast else alternatively directly to Method D.
films of the total vehicle solids to detect spectral differences
5.3 Method B is useful in detecting adulterations that are
between the reference and test samples caused by gross or
unsaponifiable or else have an unsaponifiable component that
minor adulteration of the test sample.
has escaped detection in MethodAonly because the adulterant
may have been small in amount and therefore its strong
4.3 Method B involves infrared spectral analysis of cast
spectral peaks may have been masked over by the rest of the
films of the unsaponifiable matter that has been separated from
vehicle solids. Some care should be taken in interpreting
the vehicle solids in order to detect spectral differences
spectral differences in Method B to avoid an erroneous
between the reference and test samples caused by lesser
conclusion that the test sample is unacceptable because its
adulterations of an unsaponifiable nature and which was not
spectrumisdifferent.Apparentbutunrealdifferencescanoccur
readily evident when using Method A.
as a result of incomplete saponification, failure to remove all
4.4 Method C involves gas chromatographic analysis of
saponifiable material, and varying degrees of contamination of
prepared methyl esters of the separated fatty acids obtained
the unsaponifiable fraction with sterols, etc., present in the
from the vehicle solids in order to detect chromatographic
vehicle solids. After it has thus been firmly established that a
differences between the reference and test samples caused by
realspectraldifferencedoesexist,furthertestsareunnecessary,
eithergrossorlesseradulterationofthedryingoilfractionwith
except that it is wise to resort again to the published literature
extraneous drying oils which may not have been readily
on infrared to attempt to identify the possible nature of the
evident by the use of Methods A and B.
adulterant. Where Methods A and B indicate acceptability of
4.5 Method D involves quantitative ultraviolet spectral
the test sample, it is still not always possible to rule out
analysis of the total vehicle solids dissolved in a nonaromatic
adulteration caused by changes or modifications in the saponi-
spectral grade solvent to give precise concentrations in order to
fiable portion, that is, the type of fatty acid, dibasic acids, and
detect ultraviolet spectral absorbance differences between the
polyol. In such cases, it is best to continue on to Method C for
reference and test samples caused by minor or sophisticated
determination of the oil acids, and to other gas chromato-
adulterations of the vehicle solids and which may not be
graphic methods for the polyol and dibasic acids when such
readily detected by Method A. Method D is to be used as an
equipment is available.
alternative to Methods B and C.
5.4 Method C is extremely sensitive in detecting adultera-
tions and changes that have been made in the oil or fatty acid
5. Selection of Test Methods and Significance and Use
portion of the vehicle solids. It can, for example, detect
5.1 All of the methods provided involve comparisons be- whetherlinseed,coconut,oiticica,etc.,hasbeensubstitutedfor
tween the spectra or chromatograms of the reference and test
soya oil and vice versa, or whether fish or tall oil has partially
samples to determine if they show significant differences. It is
or wholly replaced some other drying oil, etc. Consequently,
not possible at this time to establish quantitative limits as a
when the results of Methods A and B suggest that the test
guide to whether a spectral or chromatographic difference is
sample is acceptable and where a drying oil component is
truly significant. Certainly the presence or absence of a
known to be present, Method C should be used additionally for
moderate or strong peak in the test sample which is not evident
more complete assurance of product uniformity. Where the
in the reference is significant. A persistent difference in the
results from Method C along with those from Methods A and
ratios of two peaks of one spectrum as compared to the
Bindicateproductuniformity,itisafairlysafeassumptionthat
reference sample is significant. On the whole, some judgment
the product has not been significantly altered.
must be exercised in this respect and it is advisable to refer to
5.5 MethodDisintendedasanalternativetoMethodsBand
published data on infrared or gas chromatography in order to
C and where the results from Method A indicate apparent
establish, where feasible, the possible overall nature of the
product acceptability. Method D, by the use of quantitative
adulterant or its functional group which might be causing the
ultraviolet spectral absorbance data, is an extremely sensitive
comparison spectra to differ.
procedure for the detection of complete or even partial adul-
5.2 Method A is rapid and the most convenient of the terationofthetestsample.However,considerablecautionmust
procedures given. It should be utilized first in order to detect be exercised in the preliminary pre-drying of the vehicle solids
nonuniformity of the test sample. Significant spectral differ- since it is at this stage that the components are extremely
ences from that of the reference sample can be taken as an sensitive to oxidative changes. Even minor oxidative changes
indication of adulteration and in such cases the use of the other can seriously affect the absorbance data obtained in ultraviolet
methods is not necessary. As a general rule. Method A is spectral analysis and may give an impression that the two
D2743 − 68 (2010)
samples being compared are different when in fact they are the desired, an aid in comparison is to run the test sample against
same. When these considerations are provided for, and the the reference sample in the reference beam in order to show
comparison spectra are identical in Method D as well as in significant differences by means of a single differential spec-
MethodA,thenitcanbeassumedthatthesampleisacceptable. trum. Considerable caution is required in the use and interpre-
Significant differences in the spectra from Method D would tation of differential spectra as well as proper adjustments of
indicate nonuniformity of the product even though Method A gain, speed, and slit programs.
may fail to reveal such nonuniformity.
12. Interpretation of Results
6. Reference Sample
12.1 Compare the companion spectra from the test and
6.1 The reference sample of traffic paint should be at least
reference samples for identity by visual inspection preferably
250 mL and should be truly representative of the initial paint
over a light box. Note particularly the presence of an extrane-
found acceptable in pre-qualification laboratory or field service
ous peak or peaks in one which is (are) not in the other. Also
tests, or both, and which paint is subsequently specified for
note the ratio of intensities of two adjacent or pairs of peaks on
purchase.
one spectra and determine whether this ratio is similar on the
6.2 In cases where paint is purchased on the basis of
comparison spectra. Any significant difference should be con-
formulation specifications and it is desired to utilize these
sidered as an indication of lack of uniformity between the
procedures to detect adulteration in delivered lots of paint,
referenceandtestsamples.Attempttoascribethisdifferenceto
reference samples may be synthetically prepared to represent
some extraneous component or formulation difference between
the extremes of the range that will be permitted in the
the comparison samples by referring to available infrared
formulation.
literature and published spectra. Where it is evident that the
comparison spectra are significantly different, no further tests
7. Test Sample
are necessary. When the spectra are identical, proceed to
Methods B and C or alternatively to Method D for a fuller
7.1 The test samples of the traffic paint should be at least
evaluation of possible minor or more sophisticated adultera-
250 mL and should be representative of each delivered lot of
tion.
paint that was specified for purchase and which is intended to
be the same as the initial reference paint used in the pre-
METHOD B—INFRARED SPECTRAL ANALYSIS OF
qualifications acceptance tests from which a reference sample
UNSAPONIFIABLE MATTER FROM VEHICLE
was retained.
SOLIDS
8. Sampling Reference and Test Samples
13. Apparatus
8.1 Test and reference samples of the traffic paint should be
obtained in accordance with Practice E105. 13.1 Same as in 10.1.
9. Preparation of Samples
14. Procedure
9.1 Separate the vehicle from the pigment by centrifuging
14.1 Treat a portion of the separated vehicle from both the
the paint in accordance with Practice D2372. Transfer and
sample and reference paints so as to obtain an ether solution of
preserve the vehicle in a well-stoppered amber bottle.
the unsaponifiable matter in accordance with Test Method
D1397. Take care to ensure rigorous quantitative separations
METHOD A—INFRARED SPECTRAL A
...
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