Standard Test Methods for Rosin Acids Content of Naval Stores, Including Rosin, Tall Oil, and Related Products

SIGNIFICANCE AND USE
This is revision of the method for measuring rosin acids content combines the three major ways of determining the rosin acids content of naval stores products into a single method.
4.1.1 For materials containing less than 15 % rosin, the modified Glidden procedure has gained acceptance over the Herrlinger-Compeau. For materials containing more than 15 % rosin the modified Wolfe Method is preferred. The modified Wolfe and modified Glidden procedures differ only in their details. They have been combined here into a single procedure. This procedure can be run using either a potentiometer or an internal indicator to determine the end point of the titration. Use of a potentiometer is preferred and is the referee method. Use of an internal indicator is the principal alternative method. They will be referred to as the Potentiometric Method and the Internal Indicator Method to distinguish them from the Herrlinger-Compeau and Linder-Persson methods.
4.1.2 The Herrlinger-Compeau Method is limited in application to materials containing less than 15 % rosin. It is little used in the industry today. Much early work is based on this test method so it is included here to provide a historical basis for the overall test method.
4.1.3 The Linder-Persson Method is also little used in the industry today. It is applicable for measuring the rosin acids content of naval stores products containing greater than 60 % rosin. Like the Herrlinger-Compeau, it is included here to provide a historical basis for the test method. In those instances where they are used, the Herrlinger-Compeau and Linder-Persson methods are often in conjunction to cover the whole range of rosin content.
SCOPE
1.1 These test methods cover the determination of rosin acids in tall oil, tall oil fatty acid, tall oil rosin, and other naval stores products.
1.2 These test methods may not be applicable to adducts or derivatives of rosin, fatty acid, or other naval stores products.
1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
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.

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Historical
Publication Date
31-Oct-2006
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ASTM D1240-02(2006) - Standard Test Methods for Rosin Acids Content of Naval Stores, Including Rosin, Tall Oil, and Related Products
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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: D1240 − 02 (Reapproved 2006)
StandardTest Methods for
Rosin Acids Content of Naval Stores, Including Rosin, Tall
Oil, and Related Products
This standard is issued under the fixed designation D1240; 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 selective esterification of fatty acids to form methyl esters
followedbyextractionofthesulfuricacidcatalystandtitration
1.1 These test methods cover the determination of rosin
of the unreacted rosin acids.
acids in tall oil, tall oil fatty acid, tall oil rosin, and other naval
stores products.
4. Significance and Use
1.2 These test methods may not be applicable to adducts or
4.1 This is revision of the method for measuring rosin acids
derivatives of rosin, fatty acid, or other naval stores products.
content combines the three major ways of determining the
1.3 The values stated in SI units are to be regarded as the
rosin acids content of naval stores products into a single
standard. The values given in parentheses are for information
method.
only.
4.1.1 For materials containing less than 15% rosin, the
1.4 This standard does not purport to address all of the
modified Glidden procedure has gained acceptance over the
safety concerns, if any, associated with its use. It is the
Herrlinger-Compeau.Formaterialscontainingmorethan15%
responsibility of the user of this standard to establish appro-
rosin the modified Wolfe Method is preferred. The modified
priate safety and health practices and determine the applica-
Wolfe and modified Glidden procedures differ only in their
bility of regulatory limitations prior to use.
details.Theyhavebeencombinedhereintoasingleprocedure.
This procedure can be run using either a potentiometer or an
2. Referenced Documents
internal indicator to determine the end point of the titration.
2.1 ASTM Standards:
Use of a potentiometer is preferred and is the referee method.
D1585Test Methods for Fatty Acids Content of Naval
Useofaninternalindicatoristheprincipalalternativemethod.
Stores, Including Rosin, Tall Oil, and Related Products
They will be referred to as the Potentiometric Method and the
E70Test Method for pH of Aqueous Solutions With the
Internal Indicator Method to distinguish them from the
Glass Electrode
Herrlinger-Compeau and Linder-Persson methods.
E177Practice for Use of the Terms Precision and Bias in
4.1.2 The Herrlinger-Compeau Method is limited in appli-
ASTM Test Methods
cation to materials containing less than 15% rosin. It is little
E691Practice for Conducting an Interlaboratory Study to
used in the industry today. Much early work is based on this
Determine the Precision of a Test Method
test method so it is included here to provide a historical basis
3. Summary of Test Method for the overall test method.
4.1.3 The Linder-Persson Method is also little used in the
3.1 The rosin acids content is determined by one of three
industry today. It is applicable for measuring the rosin acids
procedures; by selective esterification of fatty acids to form
content of naval stores products containing greater than 60%
methylestersfollowedbytitrationoftheunreactedrosinacids,
rosin. Like the Herrlinger-Compeau, it is included here to
by selective esterification of fatty acids to form butyl esters
provideahistoricalbasisforthetestmethod.Inthoseinstances
followed by titration of the unreacted rosin acids, or by
where they are used, the Herrlinger-Compeau and Linder-
Persson methods are often in conjunction to cover the whole
These test methods are under the jurisdiction of ASTM Committee D01 on
range of rosin content.
Paint and Related Coatings, Materials, and Applications and are the direct
responsibility of Subcommittee D01.34 on Naval Stores.
Current edition approved Nov. 1, 2006. Published November 2006. Originally
5. Reagents
approved in 1952. Last previous edition approved in 2002 as D1240–02. DOI:
10.1520/D1240-02R06.
5.1 Purity of Reagents—Reagent grade chemicals shall be
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
used in all tests. Unless otherwise indicated, it is intended that
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
all reagents shall conform to the specifications of the Commit-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. tee onAnalytical Reagents of theAmerican Chemical Society
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D1240 − 02 (Reapproved 2006)
where such specifications are available. Other grades may be errors due to evaporation. The automatic buret should be
used, provided it is first ascertained that the reagent is of guarded with soda-lime tubes against the absorption of CO
sufficiently high purity to permit its use without lessening the from the air.
accuracy of the determination.
9.4 Erlenmeyer Flask, 250-mL or larger of a chemically
5.2 Unless otherwise indicated, references to water shall be resistant glass with a standard-taper 24/40 joint.
understood to mean deionized or distilled water.
9.5 Condenser, water-cooled, equipped with a joint fitting
the flask described in accordance with 9.4.
6. Preparation of Sample
10. Reagents
6.1 Homogeneous liquid materials may be used without
further preparation.
10.1 Alcoholic Alkali, Standard Solution (0.5 N)—Dissolve
33 g of potassium hydroxide (KOH), preferably in pellet form,
6.2 Nonhomogeneous liquid materials should be heated
in methanol (CH OH) and dilute to 1 L with methanol.
until they are homogeneous, then a portion taken for analysis. 3
Standardize to 60.001 N with potassium acid phthalate
6.3 Solid samples are subject to surface oxidation which
(C H COOKCOOH) in 60 mLof water followed by 40 mLof
6 4
may affect the results. Prepare the sample for analysis by
methanol; 2.553 g of potassium acid phthalate will be neutral-
chippingsmallpiecesfromafreshlyexposedsurfaceofalump
ized by 25.00 mL of 0.5 N KOH solution. Protect the
or lumps and crush to a coarse powder to facilitate weighing
standardized solution against evaporation and absorption of
andsolution.Preparefreshonthesameday,priortoweighing,
carbon dioxide (CO ) from the air. Restandardize the solution
in order to avoid changes due to surface oxidation of crushed
frequently, either potentiometrically or colorimetrically, using
rosin on exposure to the air.
phenolphthalein as the indicator.
10.1.1 Forfattyacidscontaininglowconcentrationsofrosin
ROSIN ACIDS CONTENT BY THE
acids, 0.1 N alcoholic potassium hydroxide may give superior
POTENTIOMETRIC METHOD
results.
(Referee Method)
10.2 Ethanol (95 %)—Denatured alcohol conforming to
7. Scope
Formula No. 3A or No. 30 of the U.S. Bureau of Internal
Revenue, neutralized by the addition of KOH.
7.1 Thistestmethodcoversthedeterminationofrosinacids
contentoftalloilrosin,talloilfattyacid,andothernavalstores
10.3 Methanol (99.5%).
products, where the most reproducible results are desired. By
10.4 Methyl Sulfuric Acid Solution—Slowly pour 100 g of
using the potentiometric inflection end points, the error due to
concentrated sulfuric acid (H SO sp gr 1.82 to 1.84), while
2 4
colorimetric end points is avoided.
stirring constantly, into 400 g of methanol. Extreme caution
should be taken while preparing the methyl sulfuric acid.
8. Summary of Test Method
Adding sulfuric acid too rapidly may cause the methanol to
8.1 Asampleisrefluxedwithmethylsulfuricacidtoesterify
flash out of its container. Store the methyl sulfuric acid in a
the fatty acids. The rosin acids and sulfuric acid are then
glass-stoppered bottle.
titrated potentiometrically, and the rosin acids content calcu-
10.5 Toluene.
lated from the difference between the two inflection points
obtained.
11. Procedure
11.1 Weigh the sample to the nearest 0.001 g in a 250-mL
9. Apparatus
flask.Choosetheamountofsamplesothatthesecondtitration
9.1 pH Meter—An indicating potentiometer having a limit
will consume between 10 and 30 mL of KOH solution. For
oferrornotgreaterthan 60.1pHoverarangefrompH1topH
rosin acids, this will be about5gof material. For fatty acids
13, using an alkali-resistant glass electrode and a saturated
containing less than 15% rosin, this will be about 40 g of
calomel half-cell. The pH meter shall conform to the require-
material. For fatty acids containing less than 3% rosin acids
ments of Test Method E70.Alternatively, an automatic poten-
titrating with 0.1 N KOH may give superior results. Table 1
tiometric titrator may be used.
gives suggested amounts of material to use.
9.2 Stirrer, magnetic, equipped with
11.2 Dissolve the sample in 100 mL of methanol in a
poly(tetrafluoroethylene)-coated stir bar.
250-mLflask. If the sample has a high rosin content it may be
helpfulfirsttodissolveitin25mLoftoluenebeforeaddingthe
9.3 Buret, 50-mL capacity, with 0.1-mL divisions. The
so-called automatic buret is preferable as its use minimizes
TABLE 1 Sample Size and Titrant
Sample Size, Reflux Time, KOH
Material g min Normality,
Reagent Chemicals, American Chemical Society Specifications , American
N
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
listed by the American Chemical Society, see Analar Standards for Laboratory
Rosin 5 2 0.5
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Fatty acid, <15 % rosin 40 20 0.5
and National Formulary,U.S.PharmaceuticalConvention,Inc.(USPC),Rockville, Fatty acid, <3 % rosin 40 20 0.1
MD.
D1240 − 02 (Reapproved 2006)
methanol.Formaterialbelievedtocontainlessthan15%fatty stores products, using an internal indicator for the determina-
acid, that is, high in rosin, add 5 mL of methyl sulfuric acid, tion of the end point. It gives good results when routinely
connect the flask assembly, and reflux the solution for 2 min. applied by a skilled analyst. However, where the most repro-
(Solid samples must be in solution before beginning reflux.) ducible results by different analysts and laboratories are de-
For materials believed to contain concentrations of fatty acid sired, the referee method (Sections 6 to 11) should be used.
higher than 15%, that is, low in rosin, use 10 mL of methyl
14. Summary of Test Method
sulfuric and reflux for 20 min. Measure reflux time from the
moment the first drop of solvent returns to the flask from the
14.1 A sample is refluxed with methyl sulfuric acid to
condenser. Cool and transfer to a 400-mLbeaker, using a total
esterify the fatty acids. The rosin acids and sulfuric acid are
of 100 mL of methanol (Note 1) in three successive rinsings.
thentitratedinthepresenceofthymolblueindicator.Therosin
acidscontentisthencalculatedfromthedifferencebetweenthe
NOTE 1—Ethanol is preferable when an automatic titrator is used.
two color end points obtained.
11.3 TurnthepHmeteronandallowafewminutesforitto
cometoequilibrium.Balancethemeterusingastandardbuffer
15. Apparatus
solution as described in Test Method E70; then rinse the
15.1 The apparatus for the esterification and titration of the
electrodes thoroughly with water and then with alcohol.
sample shall consist of the flask, condenser, and buret de-
11.4 Immerse the electrode in the sample solution. Start the
scribed in Section 9.
stirrer and adjust its speed for vigorous stirring without
splattering.
16. Reagents
11.5 Titrate the sample solution with 0.5 N KOH to a fixed
16.1 Alcoholic Alkali, Standard Solution—See 10.1.
pH of 4.0, the first end point. If it appears that the buret does
16.2 Methanol—See 10.3
not contain sufficient KOH to continue the titration to the
16.3 Methyl Sulfuric Acid Solution—See 10.4.
second end point, refill the buret at this point. Continue the
titration to the fixed pH of 10.8, the second point. Record the
16.4 Thymol Blue Indicator Solution (1 g/L)—Dissolve 1 g
amount of KOH required for the titration between the first and
of thymol blue in 1000 mL of methanol.
secondendpoint.Ifanautomatictitratorisused,theendpoints
16.5 Toluene.
shall be taken at the inflection points or at the fixed pH of 4.0
and 10.8.
17. Procedure
12. Calculation
17.1 Weigh the sample to the nearest 0.001 g in a 250-mL
flask. Choose the amount of sample so that the titration will
12.1 Calculate the percentage of rosin acids as follows:
consumebetween10and30mLof0.5 NKOH.Forrosinacids,
12.1.1 For materials containing less than 15% rosin:
thiswillbeabout5gofmaterial.Forfattyacidscontainingless
Rosinacids, % 5 AN/B 330.24 21.1 (1)
@~ ! #
than 15% rosin, this will be about 40 g of material. For fatty
where: acids containing less than 3% rosin acids, titrating with 0.1 N
KOH may give superior results. Table 1 gives suggested
A = KOH solution required for titration between the
amounts of material to use.
first and second end points, mL,
N = normality of the KOH solution,
17.2 Dissolve the sample in 100 mL of methanol in a
B = sample used, g, and
250-mLflask. If the sample has a high-rosin content it may be
30.24 = (mol weight of abietic acid×100)/1000
helpfulfirsttodissolveitin25mLoftoluenebeforeaddingthe
12.1.2 For materials containing greater than 15% rosin: methanol.Formaterialbelievedtocontainlessthan15%fatty
acid, add 5 mL of methyl sulfuric acid, connect the flask
Rosinacids, % 5 ~AN/B! 330.24 (2)
assembly, and reflux the solution for 2 min. (Solid samples
where:
must be in solution before beginning reflux.) For materials
A = KOH solution required for titration between the
believed to contain concentrations of fatty acid higher than
first and second end points, mL, 15%, use 10 mL of methyl sulfuric and reflux for 20 min.
N = normality of the KOH solution,
Measure reflux time from the moment the first drop of solvent
B = sample used, g, and
returns to the flask from the condenser. Cool, add 1 mL of
30.24 = (mol wt of abietic acid×100)/1000
thymol blue indicator.
12.2 Report the percentage of rosin acids calculated by
17.3 Titrate with the KOH solution to the first end point,
either 12.1.1 or 12.1.2 to the first decimal place.
about pH 4.0, when the solution changes color from red to
yellow. Record the reading or refill the buret. Continue the
ROSIN ACIDS CONTENT BY THE INTERNAL
titration to the second end point, about pH 10.8, when the
INDICATOR METHOD
solution changes color from yellow to blue. Record to the
(Alternative Method)
nearest 0.1 mL the millilitres of KOH solution required for
13. Scope titration between the two end points.
13.1 This test method covers the determination of rosin
NOTE 2—These end points approximate the inflection points under the
acidscontentoftalloilrosi
...

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