ASTM D3125-06
(Test Method)Standard Test Method for Monomethyl Ether of Hydroquinone in Colorless Monomeric Acrylate Esters and Acrylic Acid
Standard Test Method for Monomethyl Ether of Hydroquinone in Colorless Monomeric Acrylate Esters and Acrylic Acid
SIGNIFICANCE AND USE
Acrylic acid and its esters are normally inhibited with MEHQ only. This procedure presents a rapid and accurate method of determining the MEHQ content of fresh acrylic acid and acrylate esters in the absence of other inhibitors.
MEHQ effectiveness may decline with age and this decline in effectiveness may not be indicated by this test method.
SCOPE
1.1 This test method covers the determination of monomethyl ether of hydroquinone (MEHQ) in colorless monomeric acrylate esters and acrylic acid. The test method is applicable to the determination of MEHQ in the concentration range from 0 to 1200 parts per million.
1.2 For purposes of determining conformance of an observed or a calculated value using this test method to relevant specifications, test result(s) shall be rounded off "to the nearest unit" in the last right-hand digit used in expressing the specification limit, in accordance with the rounding-off method of Practice E 29.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 For hazard information and guidance, see the supplier's Material Safety Data Sheet.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of whoever uses this standard to consult and establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8.
General Information
Relations
Standards Content (Sample)
Designation: D3125 − 06
Standard Test Method for
Monomethyl Ether of Hydroquinone in Colorless Monomeric
1
Acrylate Esters and Acrylic Acid
This standard is issued under the fixed designation D3125; 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.
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1. Scope* cialty Chemicals (Withdrawn 2009)
1.1 This test method covers the determination of monom-
2 3. Summary of Test Method
ethyl ether of hydroquinone (MEHQ) in colorless monomeric
acrylate esters and acrylic acid. The test method is applicable
3.1 As shown in the equation, MEHQ reacts with nitrous
to the determination of MEHQ in the concentration range from acid (sodium nitrite in acidic media) to form the nitroso
0 to 1200 parts per million. derivative which equilibrates between two structures.
1.2 For purposes of determining conformance of an ob-
served or a calculated value using this test method to relevant
specifications, test result(s) shall be rounded off “to the nearest
unit” in the last right-hand digit used in expressing the
specification limit, in accordance with the rounding-off method
of Practice E29.
3.2 The yellow color of the nitroso compound is measured
1.3 The values stated in SI units are to be regarded as
spectrophotometrically at a wavelength of 420 nm.
standard. No other units of measurement are included in this
standard.
4. Significance and Use
1.4 For hazard information and guidance, see the supplier’s
4.1 Acrylic acid and its esters are normally inhibited with
Material Safety Data Sheet.
MEHQ only. This procedure presents a rapid and accurate
1.5 This standard does not purport to address all of the
method of determining the MEHQ content of fresh acrylic acid
safety concerns, if any, associated with its use. It is the
and acrylate esters in the absence of other inhibitors.
responsibility of whoever uses this standard to consult and
4.2 MEHQ effectiveness may decline with age and this
establish appropriate safety and health practices and deter-
decline in effectiveness may not be indicated by this test
mine the applicability of regulatory limitations prior to use.
method.
Specific precautionary statements are given in Section 8.
2. Referenced Documents
5. Interferences
3
2.1 ASTM Standards:
5.1 Hydroquinone (HQ), thiodiphenylamine, diphenylphe-
D1193 Specification for Reagent Water
nylene-diamine and p-hydroxydiphenylamine interfere if pres-
E29 Practice for Using Significant Digits in Test Data to
ent.
Determine Conformance with Specifications
E180 Practice for Determining the Precision of ASTM
6. Apparatus
Methods for Analysis and Testing of Industrial and Spe-
6.1 Spectrophotometer, with borosilicate-glass cells for de-
termining absorbance at 420 nm.
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This test method is under the jurisdiction of ASTM Committee D01 on Paint
6.2 Volumetric Flasks, 50 and 100-mL capacity.
and Related Coatings, Materials, andApplications and is the direct responsibility of
Subcommittee D01.35 on Solvents, Plasticizers, and Chemical Intermediates.
6.3 Measuring Pipets, 5 and 10-mL capacity.
Current edition approved June 1, 2006. Published June 2006. Originally
approved in 1972. Last previous edition approved in 2001 as D3125 – 97 (2001).
7. Reagents
DOI: 10.1520/D3125-06.
2
IUPAC-approved name is 4-methoxyphenol.
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
4
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
*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
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D3125 − 06
TABLE 1 Amount of Specimen
dilute to the mark with glacial acetic acid. Prepare a series of
Expected MEHQ Content, ppm Amount of Specimen, g standards by pipetting 1, 2, 4, 6, and 10-mL portions of the
A
0to25 25 MEHQ solution into respective 50-mL volumetric flasks.
A
25 to 100 10
Dilute each flask to the mark with glacial acetic acid and mix
B
100 to 250 5
B well. A10-mL aliquot of each of these standards contains
250 to 550 2
B
550 to 1000 1 approximately 200, 400, 800, 1200, and 2000 µg of MEHQ,
A
respectively.
Weigh to the nearest 10 mg.
B
Weigh to the nearest 1 mg.
9.2 Determine the absorbance of each of these standards by
pipetting10-mLaliquotsinto50-mLvolumetricflaskscontain-
ing20-mLofglacialaceticacid.Toeachflaskadd1-mLof2 %
TABLE 2 Reporting and Averaging of Duplicate Runs
NaNO solution and dilute to the mark with glacial acetic acid.
2
Duplicate Runs That Agree Within
MEHQ
Mix well and allow to stand for 10 min. Wit
...
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