ASTM D5554-15(2021)

Standard Test Method for Determination of the Iodine Value of Fats and Oils

SIGNIFICANCE AND USE
2.1 This test method is intended for the determination of the iodine value of fats and oils that do not contain conjugated double bonds. The iodine value is a measure of the unsaturation of fats and oils and is expressed in terms of the number of centigrams of iodine absorbed per gram of sample.
SCOPE
1.1 This test method covers the determination of the iodine value of fats and oils.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 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.

General Information

• Status: Published
• Publication Date: 30-Nov-2021
• ICS: 75.080 - Petroleum products in general
• Technical Committee: D31 - Leather
• Drafting Committee: D31.08 - Fats and Oils

Standards Content (Sample)

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.
Designation: D5554 − 15 (Reapproved 2021)
Standard Test Method for
Determination of the Iodine Value of Fats and Oils
This standard is issued under the fixed designation D5554; 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 3.4 Two Pipettes, 25 mL. One pipette is reserved for use
with the standard potassium dichromate solution and shall
1.1 This test method covers the determination of the iodine
conform to NIST tolerances and be calibrated to deliver
value of fats and oils.
25 mL.
1.2 The values stated in SI units are to be regarded as
3.5 Glacial Acetic Acid, A.C.S. grade. The permanganate
standard. No other units of measurement are included in this
test shall be applied to be sure that this specification is met.
standard.
3.5.1 Two millilitres of the glacial acetic acid shall be
1.3 This standard does not purport to address all of the
diluted with 10 mL of distilled water and 0.1 mL of 0.1 N
safety concerns, if any, associated with its use. It is the
KMnO shall be added. The pink color shall not be entirely
responsibility of the user of this standard to establish appro-
discharged within 2 h.
priate safety, health, and environmental practices and deter-
3.6 Potassium Iodide, A.C.S. grade.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
3.7 Chlorine, 99.8 %. Satisfactory commercial grades are
dance with internationally recognized principles on standard-
available in cylinders, but this gas must be dried by passing
ization established in the Decision on Principles for the
through sulfuric acid (sp. gr. 1.84) before introducing into the
Development of International Standards, Guides and Recom-
iodine solution.
mendations issued by the World Trade Organization Technical
3.7.1 Chlorine may be prepared by allowing hydrochloric
Barriers to Trade (TBT) Committee.
acid (sp. gr. 1.19) to drop onto potassium permanganate or on
a mixture of potassium permanganate and manganese dioxide.
2. Significance and Use
The gas thus generated shall be led through a glass tube into
sulfuric acid (sp. gr. 1.84) and then into the iodine solution.
2.1 This test method is intended for the determination of the
iodine value of fats and oils that do not contain conjugated
3.8 Carbon Tetrachloride, A.C.S. grade. (Warning—
doublebonds.Theiodinevalueisameasureoftheunsaturation
Carbon Tetrachloride is a known carcinogen. It is toxic by
of fats and oils and is expressed in terms of the number of
inhalation, ingestion and skin absorption. Always handle Car-
centigrams of iodine absorbed per gram of sample.
bon Tetrachloride inside a fume hood. Use only with adequate
ventilation.)
3. Apparatus and Reagents
3.9 Cyclohexane , A.C.S. grade.
3.1 Glass-Stoppered Bottles or Wide Mouth Erlenmeyer
3.10 ReagentforDilutingSample—Prepare by mixing fresh
Flasks, 500 mL. Wide mouth bottles or flasks are essential if
cyclohexane and glacial acetic acid, 1:1, v/v. (After mixing,
stirring is done by mechanical means.
verify the absence of oxidizable matter in the reagent by
3.2 Glass-Stoppered Volumetric Flasks, conforming to
shaking 10 mL of the reagent with 1 mL of saturated aqueous
NIST tolerances and accurately calibrated to contain
potassium dichromate solution and 2 mL of concentrated
1000 mL.
sulfuric acid: no green coloration should appear. A green
coloration indicates presence of oxidizable matter, so discard
3.3 Pipette, 20 mL.
and remix using fresh cyclohexane.)
3.11 Hydrochloric Acid, A.C.S. grade, sp. gr. 1.19.
This test method is under the jurisdiction ofASTM Committee D31 on Leather
and is the direct responsibility of Subcommittee D31.08 on Fats and Oils. This test 3.12 Soluble Starch, of suitable sensitivity.
method was developed in cooperation with the American Leather Chemists Assn.
3.12.1 The test for starch sensitivity shall be made by
(Method H 32-1957).
adding, while stirring, 200 mLof boiling water to a paste made
Current edition approved Dec. 1, 2021. Published January 2022. Originally
approved in 1994. Last previous edition approved in 2015 as D5554 – 15. DOI:
10.1520/D5554-15R21.
2 3
Available from National Institute of Standards and Technology, (NIST), Comparison study showed excellent agreement between Carbon Tetrachloride
Gaithersburg, MD 20899. and Cyclohexane (ISO/IUPAP Smalley program).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5554 − 15 (2021)
with1gof starch in a small amount of water. After placing bring back to the desired titration by addition of some of the
5 mL of this solution in 100 mL of water, add 0.05 mL of 0.1 original iodine solution that was taken out at the beginning.
N iodine solution. The deep blue color produced must be TheoriginaliodinesolutionandthefinishedWijssolutionshall
discharged by 0.05 mL of 0.1 N sodium thiosulfate. both be titrated with Na S O solution as directed in 4.6.
2 2 3
3.13 Potassium Dichromate, A.C.S. grade, shall be finely
NOTE 1—All Wijs solutions are sensitive to temperature, moisture, and
light. Store them in a cool and dark place and never allow them to come
ground and dried to constant weight at about 110 °C before
to a temperature much above 30 °C.
using. (A standard sample of potassium dichromate with a
certificate of analysis may be obtained from NIST. This
4. Procedure
sample is strongly recommended as the primary standard for
4.1 Melt the sample, if not already completely liquid, and
this test method. The dichromate should be treated as directed
filter through filter paper to remove any impurities and the last
in the certificate of analysis accompanying the sample.)
traces of water. (Care shall be taken not to exceed 10 °C to
3.14 Sodium Thiosulfate—(Na S O ·5H O), A.C.S. grade.
15 °C above the sample melting point during melting and
2 2 3 2
filt
...