ASTM D5974-00(2005)

Standard Test Methods for Fatty and Rosin Acids in Tall Oil Fractionation Products by Capillary Gas Chromatography

SCOPE
1.1 These test methods cover the determination of the amounts of the individual fatty acids and rosin acids in fractionated tall oil products, using capillary gas chromatographic separation of the volatile methyl esters of these acids.
1.2 Four methods for forming the methyl esters, and two methods for determining the amounts of the individual fatty acids and rosin acids are described.
1.2.1 The classic method for the formation of methyl esters is through the use of diazomethane, but diazomethane is a hazardous and toxic material, and so is no longer the preferred reagent. The use of diazomethane is detailed in the Appendix. Methyl esters may be formed through the use of tetramethylammonium hydroxide (TMAH), trimethylphenylammonium hydroxide (TMPAH), or N,N-dimethylformamide dimethyl acetal (DMF-DMA).
1.2.2 The two methods for determining the amount of the individual fatty acids and rosin acids are the "internal standard" method, which yields absolute values, and the "area percent" method, which yields relative values.
1.3 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: 30-Nov-2005
• ICS: 67.080.10 - Fruits and derived products
• ICS: 67.200.10 - Animal and vegetable fats and oils
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.34 - Pine Chemicals and Hydrocarbon Resins

Relations

• Replaces: ASTM D5974-00 - Standard Test Methods for Fatty and Rosin Acids in Tall Oil Fractionation Products by Capillary Gas Chromatography
• Effective Date: 01-Dec-2005
• Replaced By: ASTM D5974-00(2010) - Standard Test Methods for Fatty and Rosin Acids in Tall Oil Fractionation Products by Capillary Gas Chromatography
• Effective Date: 01-Jun-2010
• Referred By: ASTM D509-20 - Standard Test Methods of Sampling and Grading Rosin
• Effective Date: 01-Dec-2005
• Referred By: ASTM D803-15(2020) - Standard Test Methods for Testing Tall Oil
• Effective Date: 01-Dec-2005

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D5974–00(Reapproved2005)
Standard Test Methods for
Fatty and Rosin Acids in Tall Oil Fractionation Products by
Capillary Gas Chromatography
This standard is issued under the fixed designation D5974; 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 E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 These test methods cover the determination of the
amounts of the individual fatty acids and rosin acids in
3. Significance and Use
fractionated tall oil products, using capillary gas chromato-
3.1 Tall oil fractionated products derived from tall oil are
graphic separation of the volatile methyl esters of these acids.
important commercial materials, primarily composed of fatty
1.2 Four methods for forming the methyl esters, and two
acidsandrosinacids,butalsocontainingsomeneutralmaterial
methods for determining the amounts of the individual fatty
(seeTerminologyD804).Formanyapplications,itisnecessary
acids and rosin acids are described.
to know the level of the individual fatty acids and rosin acids
1.2.1 The classic method for the formation of methyl esters
present in these products. Gas chromatography has proven to
is through the use of diazomethane, but diazomethane is a
be a useful tool for such determinations (see Test Methods
hazardous and toxic material, and so is no longer the preferred
D509), and capillary chromatography, described in these test
reagent. The use of diazomethane is detailed in the Appendix.
methods, is considered to be the most effective gas chromato-
Methyl esters may be formed through the use of tetramethy-
graphic technique currently available. In particular situations,
lammonium hydroxide (TMAH), trimethylphenylammonium
other techniques may be more suitable than gas chromatogra-
hydroxide (TMPAH), or N,N-dimethylformamide dimethyl
phy. For example, the presence of fatty acid esters in the
acetal (DMF-DMA).
sample would result in transesterification during the derivati-
1.2.2 The two methods for determining the amount of the
zation step that may affect the results.
individualfattyacidsandrosinacidsarethe“internalstandard”
3.2 Due to hydrogen bonding, unmodified tall oil fatty acids
method, which yields absolute values, and the “area percent”
and rosin acids cannot be volatilized at atmospheric pressure
method, which yields relative values.
without undergoing decomposition. So, it is necessary to
1.3 This standard does not purport to address all of the
convert the free acids to the more volatile and more stable
safety concerns, if any, associated with its use. It is the
methyl esters, prior to chromatographic separation.
responsibility of the user of this standard to establish appro-
3.3 These test methods describe four ways to prepare
priate safety and health practices and determine the applica-
methyl esters. The classic method is through the use of
bility of regulatory limitations prior to use.
diazomethane, but diazomethane is a hazardous and toxic
2. Referenced Documents material, and so is no longer the preferred agent. The use of
2 diazomethane is detailed in the Appendix.
2.1 ASTM Standards:
3.3.1 TMAH causes isomerization of a sample’s di- and
D509 Test Methods of Sampling and Grading Rosin
polyunsaturated fatty acids, when it is used in even a slight
D804 Terminology Relating to Naval Stores, Including Tall
excess. This leads to inaccurate results for the individual fatty
Oil and Related Products
acid components.TMAH should be used for materials contain-
ing only rosin acids, or when the identification or quantitation
These test methods are under the jurisdiction of ASTM Committee D01 on of individual fatty acid components is not important.
Paint and Related Coatings, Materials, and Applications and are the direct
3.3.2 TMPAH is the recommended methylating agent when
responsibility of Subcommittee D01.34 on Naval Stores.
the identification or quantitation of individual di- and polyun-
Current edition approved Dec. 1, 2005. Published February 2006. Originally
saturated fatty acids is required. TMPAH produces results that
approved in 1996. Last previous edition approved in 2000 as D5974 – 00. DOI:
10.1520/D5974-00R05.
are very similar to those of diazomethane, but without the
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
hazards that are associated with diazomethane. A considerable
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
excess of TMPAH may cause isomerization of conjugated
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. compounds similar to that encountered with TMAH.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D5974–00 (2005)
3.3.3 DMF-DMA gives results comparable to TMPAH and point. When the solution is injected into the heated injection
is easy and safe to use. However, the reagent is moisture port of the chromatograph, the tetramethylammonium salts are
sensitive, requiring samples to be free of any significant levels pyrolyzed to methyl esters.
of water.
NOTE 2—For solid rosin, or other samples that are difficult to dissolve,
3.4 Two test methods for calculating the amounts of the
2 to 3 drops of toluene may be added to the vial prior to the addition of
individual fatty acid and rosin acid methyl esters are included
TMAH, to assist in dissolving the sample.
in these test methods. When the actual weight percentage of a
5. Conversion By Means of Trimethylphenylammonium
given compound is required, the “internal standard” method
Hydroxide (TMPAH)
mustbeused.Thismethodinvolvesaddingaknownamountof
an internal standard to a known amount of test material, and
5.1 Apparatus:
comparing the area of the peak associated with the internal
5.1.1 Standard Laboratory Equipment.
standard with the area of the peak of the individual fatty acid
5.2 Reagents and Materials:
or rosin acid methyl esters. The “area percent” method will
5.2.1 Purity of Reagents, see 4.2.1.
give the relative amount of each component, by comparing the
5.2.2 Trimethylphenylammonium Hydroxide Solution,0.2M
area of the appropriate peak to the total area of all peaks.
or 0.1 M in methanol, CAS No. 1899-02-1.
Non-eluting compounds will lead to erroneous (absolute)
5.2.3 Diethyl Ether, anhydrous.
results with this method.
5.2.4 Methanol, anhydrous.
5.2.5 Toluene, optional
PREPARATION OF METHYL ESTERS
5.3 Procedure:
5.3.1 Add 0.5 to 3.0 mL of a 50:50 ether/methanol, to the
NOTE 1—Anyofthesethreemethodscanbeused,withthechoicebeing
dependent on the factors mentioned in 3.3. sample from 9.2.2 or 17.1.Add 2 to 3 drops of phenolphthalein
indicator solution and titrate to the very first permanent pink
4. Conversion By Means of Tetramethylammonium
color with the TMPAH in methanol solution. When the
Hydroxide (TMAH)
solution is injected into the heated injection port of the
4.1 Apparatus:
chromatograph, the trimethylphenylammonium salts are pyro-
4.1.1 Standard Laboratory Equipment. lyzed to their respective methyl esters.
4.2 Reagents and Materials:
NOTE 3—For solid rosin, or other samples that are difficult to dissolve,
4.2.1 Purity of Reagents—Reagent grade chemicals shall be
2 to 3 drops of toluene may be added to the vial prior to the addition of
used in all tests. Unless otherwise indicated, it is intended that
TMPAH, to assist in dissolving the sample.
all reagents shall conform to the specifications of the Commit-
6. Conversion by Means of N,N-Dimethylformamide
teeonAnalyticalReagentsoftheAmericanChemicalSociety ,
Dimethyl Acetal (DMF-DMA)
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
6.1 Apparatus:
sufficiently high purity to permit its use without lessening the
6.1.1 Standard Laboratory Equipment.
accuracy of the determination.
6.2 Reagents and Materials:
4.2.2 Tetramethylammonium Hydroxide Solution,24% in
6.2.1 Purity of Reagents, see 4.2.1.
methanol, CAS No. 75-59-2.
6.2.2 N,N-Dimethylformamide dimethyl acetal (DMF-
4.2.3 Tetramethylammonium Hydroxide Solution, 6 % (v/v)
DMA), CAS No. 4637-24-5.
in methanol. Dilute 25 mL of the reagent described in 4.2.2
6.2.3 Methanol, anhydrous.
with 75 mL of methanol.
6.2.4 Toluene.
4.2.4 Phenolphthalein Solution, 1 % (w/v) in methanol.
6.3 Procedure:
4.2.5 Diethyl Ether, anhydrous.
6.3.1 Place the sample from 9.2.2 or 17.1 in an appropriate
4.2.6 Methanol, anhydrous.
anhydrous vial, and dissolve with approximately 0.5 mL of
4.2.7 Acetic Acid, 5 % volume/volume (v/v) in methanol.
either methanol or toluene. Add approximately 1 mL of
4.2.8 Toluene, optional.
DMF-DMA,mixwell,andmaintainthesampleat30–40°Cfor
4.3 Procedure:
15 minutes.
4.3.1 Dissolve the sample from 9.2.2 or 17.1 in 0.5 to 3.0
INTERNAL STANDARD METHOD
mL of a 50:50 ether/methanol mixture, add 2 to 3 drops of
phenolphthalein indicator solution, and titrate to a pH of 7.8 to
7. Apparatus
8.1 or to the very first permanent pink color, with the 6 %
7.1 Gas Chromatograph—An instrument equipped with a
solutionofTMAH.Ifthesolutionisovertitrated,itcanbeback
flame ionization detector (FID) that can be operated at condi-
titrated with the acetic acid in methanol solution to the end
tions given in 10.1.
7.2 Column—A high resolution column between 15 and 60
m in length, 0.25 to 0.53 mm internal diameter, with a 0.20-µm
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
film thickness of biscyanopropylsiloxane type liquid phase.
listed by the American Chemical Society, see Analar Standards for Laboratory
The recommended referee column is 30 m in length, 0.32 mm
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
internal diameter, with a 0.20-µm film thickness, and provides
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. separations equivalent or better than that displayed in Fig. 1.
D5974–00 (2005)
NOTE 1—Labeled peaks are eluted as methyl esters.
FIG. 1 Typical Chromatogram of Distilled Tall Oil
NOTE 4—When using this method for referee purposes, verify that the
9.2.2 Convert the test sample to methyl esters or substituted
resolution is adequate and comparable to that shown in Fig. 1.
ammonium salts, as described in Sections 4, 5, 6.
7.3 Analytical Balance, accurate to 0.1 mg.
10. Set-up of Gas Chromatograph (GC)
8. Reagents and Materials
10.1 Set the GC conditions so that they are approximately
8.1 Purity of Reagents, see 4.2.1.
(see Note 7) as follows:
8.2 Myristic Acid (Internal Standard), 99 % pure.
Column temperature (oven temperature)
Initial 150°C
NOTE 5—A higher molecular-weight saturated fatty acid that elutes as
Hold 5 min
a methyl ester later in the chromatogram may be used in place of, or in
Ramp 5°C/min
addition to myristic acid, provided that the alternative internal standard
Final 250°C
Hold 10 min
peak does not coelute with sample component peaks.
Injection port temperature 300°C
8.3 Stearic Acid, Oleic Acid, Linoleic Acid, Abietic Acid,
Injection port liner glass split
Detector temperature 325°C
and Dehydroabietic Acid—Other high purity reference stan-
Carrier gas helium
dards can be added as needed.
Linear gas velocity 19.5–20.5 cm/s
Split ratio 100 to 1 maximum
Detector FID
9. Procedure
Hydrogen 30 mL/min
9.1 Preparation of Calibration Standard:
Air 400 mL/min
Makeup gas 30 mL/min
9.1.1 Accurately weigh into a suitable vial, milligram quan-
tities of the myristic acid internal standard, plus the fatty acid
NOTE 7—These are typical operating conditions only. The individual
and rosin acid standards that are anticipated to be in the test
instrument should be adjusted in accordance with manufacturer’s instruc-
sample, and record the weights. tions to optimize desired performance. Ongoing adjustments in operating
temperature and flow rate may be necessary to maintain optimum
9.1.2 Convert the calibration standard to the methyl esters
performance of the column due to aging.
or substituted ammonium salts as described in Sections 4, 5, 6.
9.2 Preparation of Test Sample:
10.2 Calibration:
9.2.1 Accurately weigh ;50 mg of sample and ;15 mg of
10.2.1 Inject 0.5 to 1.0 µL of the appropriate standard
myristic acid directly into a suitable vial and record the weight.
prepared in 9.1.
10.2.2 Record the retention time and calculate the indi-
NOTE 6—Rosin samples need to be freshly broken from a larger mass
to ensure the results are not affected by air oxidation of the rosin. vidual relative response factors as follows:
D5974–00 (2005)
TABLE 1 Precision of Internal Standard Method
Repeatability Repeatability Reproducibility Reproducibility
Limit, 95 % Standard Deviation Limit, 95 % Standard Deviation
TOFA Material
Stearic acid 0.6 0.2 0.8 0.3
Oleic acid 7.6 2.7 10.4 3.7
Linoleic acid 5.0 1.8 7.3 2.6
DTO Material
Stearic acid 0.2 0.09 0.6 0.2
Oleic acid 1.4 0.5 1.7 0.6
Linoleic acid 1.1 0.4 1.4 0.5
Abietic acid 0.6 0.2 0.8 0.3
Dehydroabietic acid 0.3 0.1 0.8 0.3
ROSIN Material
Abietic acid 6.4 2.3 10.6 3.8
Dehydroabietic acid 2.0 0.7 2.8 1.0
W A
14. Precision and Bias
i IS
RRF 5 3 (1)
i
A W
i IS
14.1 Internal Standard Method—An interlaboratory study
ofthecapillaryGCdeterminationoffattyandrosinacidsintall
where:
oilfattyacids(TOFA),DTO,androsinwasrunin1995bynine
RRF = relative response factor of individual fatty or rosin
i
laboratories. The design of the experiment, similar to that of
acid methyl esters,
Practice E691, and a within-between analysis of the data are
W = weight of individual fatty or rosin acid methyl
i
given in ASTM Research Report.
esters in standard, W= weight used 3 purity,
i
A = peak area of individual fatty or rosin acid, 14.1.1 Test Result—The precision information given in
i
A = peak area of internal standard, and Table 1 for fatty and rosin acids is for the comparison of two
IS
W = weight of internal standard. W = weight used 3 test results.
IS IS
purity.
NOTE 11—Repeatability = within laboratory, Reproducibility = be-
tween laboratories.
NOTE 8—For highest accuracy, the purity of the standards should be
used to correct the weight terms.
14.1.2 Bias—Since there is no accepted reference material,
method or laboratory suitable for determining the bias for the
11. Analysis
procedure in this test method for measuring component con-
11.1 Inject0.5to1.0µLofthe
...