ASTM D2191-06(2012)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D2191 − 06 (Reapproved 2012)
Standard Test Method for
Acetaldehyde Content of Vinyl Acetate
This standard is issued under the fixed designation D2191; 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* with a standard iodine solution, is a measure of the acetalde-
hyde present in the vinyl acetate.
1.1 This test method covers the determination of trace
quantities of acetaldehyde, in the range from 0.00 to 0.05 %,
4. Significance and Use
contained in 99 % grade vinyl acetate.
4.1 This test method provides a measurement of acetalde-
1.2 For purposes of determining conformance of an ob-
hyde content in vinyl acetate. The results of these measure-
served or a calculated value using this test method to relevant
ments can be used for specification acceptance.
specifications, test result(s) shall be rounded off “to the nearest
unit” in the last right-hand digit used in expressing the
5. Interference
specification limit, in accordance with the rounding-off method
5.1 Ketonesandotheraldehydes,ifpresent,causeapositive
of Practice E29.
interference.
1.3 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
6. Apparatus
standard.
6.1 Buret, 50-mL capacity, graduated in 0.1-mL
1.4 For hazard information and guidance, see the supplier’s
subdivisions, with a funnel or flared top and a ground-glass
Material Safety Data Sheet.
stopcock.
1.5 This standard does not purport to address all of the
6.2 Erlenmeyer Flask, 500-mL capacity, glass-stoppered.
safety concerns, if any, associated with its use. It is the
6.3 Pipet, 50-mL capacity.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 6.4 Pipet, 100-mL capacity.
bility of regulatory limitations prior to use. For specific hazard
7. Reagents
statements see Section 8.
7.1 Purity of Reagents—Unless otherwise indicated, it is
2. Referenced Documents
intended that all reagents shall conform to the specifications of
theCommitteeonAnalyticalReagentsoftheAmericanChemi-
2.1 ASTM Standards:
cal Society, where such specifications are available. Other
D1193 Specification for Reagent Water
grades may be used provided that it is first ascertained that the
E29 Practice for Using Significant Digits in Test Data to
reagent is of sufficiently high purity to permit its use without
Determine Conformance with Specifications
lessening the accuracy of the determination.
3. Summary of Test Method
7.2 Purity of Water—Unless otherwise indicated, references
3.1 The acetaldehyde present in the specimen is reacted to water shall be understood to mean reagent water as defined
with a measured excess of sodium bisulfite. The amount of by Type IV of Specification D1193.
sodium bisulfite consumed, determined by titrating the excess
7.3 Iodine, Standard Solution (0.1 N)—Dissolve 35.0 g of
potassiumiodide(KI)and13.0gofresublimediodineinwater,
and dilute to 1 Lwith water. Store this solution in a dark bottle
This test method is under the jurisdiction of ASTM Committee D01 on Paint
and standardize each day, as required, against a standard 0.1 N
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.
CurrenteditionapprovedJune1,2012.PublishedJuly2012.Originallyapproved
in 1963. Last previous edition approved in 2006 as D2191 – 06. DOI: 10.1520/ Reagent Chemicals, American Chemical Society Specifications, American
D2191-06R12. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D2191 − 06 (2012)
sodium thiosulfate (Na S O ) solution. (See standardization
W = weight of KIO used, g
2 2 3
procedure, 9.3 and 9.4.)
P = correction for purity of KIO standard, and
V = volume of Na S O required for titration of the KIO ,
2 2 3 3
7.4 Potassium Iodate (KIO ), primary standard.
mL.
7.5 Sodium Bisulfite Solution (0.44 %)—Dissolve 4.4 g of
9.3 Fillthefunnel-topped50-mLburetwiththe0.1 Niodine
sodium metabisulfite (Na S O ) in 1 L of water. This solution
2 2 5
solution to be standardized. Measure approximately 40 mL of
should be prepared fresh daily or just before using.
the iodine solution into a 250-mL Erlenmeyer flask, and read
7.6 Sodium Thiosulfate, Standard Solution(0.1 N)—Weigh
the buret to the nearest 0.1 mL. Add approximately 50 mL of
to 0.1 g 24.8 g of sodium thiosulfate (Na S O ·5H O) crystals
2 2 3 2
water to the flask containing the iodine solution, and titrate
and dissolve in 500 mL of water. Dilute this solution to 1 L
with the standardized 0.1 N Na S O solution as described in
2 2 3
with water. Add 0.5 mL of chloroform per litre of solution as
9.1.
a preservative, and store in a clean dark bottle. This solution
9.4 Calculate the normality N of the iodine solution as
should be standardized weekly, as required, against potassium
iodate (KIO ). (See standardization procedure, 9.1 and 9.2.) follows:
7.7 Starch Indicator—Make a paste of 6 g of powdered N 5 ~V 3 N!/V (1)
1 1
soluble starch in water, and dilute to 1 Lwith water, stirring to
where:
produce a suspension. While stirring, add 20 g of potassium
V = volume of Na S O required for titration of the iodine
2 2 3
hydroxide (KOH) pellets, and
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