ASTM D8087-18

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: D8087 − 18
Standard Test Method for
Color of Maleic Anhydride in the Molten State and After
Heating (Platinum-Cobalt Scale) Using Tristimulus
Colorimetry
This standard is issued under the fixed designation D8087; 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 D1209 Test Method for Color of Clear Liquids (Platinum-
Cobalt Scale)
1.1 This test method covers an instrumental method for the
D1686 Test Method for Color of Solid Aromatic Hydrocar-
CIE (Commission International de l’Eclairage) tristimulus
bons and Related Materials in the Molten State (Platinum-
measurement of the color of maleic anhydride melt before and
Cobalt Scale)
after prolonged heating under specified conditions of time and
D3438 Practice for Sampling and Handling Naphthalene,
temperature. The measurement is converted to color values in
Maleic Anhydride, and Phthalic Anhydride
the platinum-cobalt system.
D5386 Test Method for Color of Liquids Using Tristimulus
1.2 This test method covers the range 0 to100 Pt-Co color.
Colorimetry
D6809 Guide for Quality Control and Quality Assurance
1.3 In determining the conformance of the test results using
thismethodtoapplicablespecification,resultsshallberounded Procedures for Aromatic Hydrocarbons and Related Ma-
terials
in accordance with the rounding off methods of Practice E29.
D8005 Test Method for Color of Clear Liquids (Platinum-
1.4 The values stated in SI units are to be regarded as
Cobalt Scale)
standard. No other units of measurement are included in this
E29 Practice for Using Significant Digits in Test Data to
standard.
Determine Conformance with Specifications
1.5 This standard does not purport to address all of the
E179 Guide for Selection of Geometric Conditions for
safety concerns, if any, associated with its use. It is the
Measurement of Reflection and Transmission Properties
responsibility of the user of this standard to establish appro-
of Materials
priate safety, health, and environmental practices and deter-
E308 PracticeforComputingtheColorsofObjectsbyUsing
mine the applicability of regulatory limitations prior to use.
the CIE System
For specific hazard statements, see Sections 7, 10.3, and 10.6.
E313 Practice for Calculating Yellowness and Whiteness
1.6 This international standard was developed in accor-
Indices from Instrumentally Measured Color Coordinates
dance with internationally recognized principles on standard-
E691 Practice for Conducting an Interlaboratory Study to
ization established in the Decision on Principles for the
Determine the Precision of a Test Method
Development of International Standards, Guides and Recom-
2.2 Other Document:
mendations issued by the World Trade Organization Technical
OSHA regulations, 29 CFR paragraphs 1910.1000 and
Barriers to Trade (TBT) Committee.
1910.1200
2. Referenced Documents
3. Summary of Test Method
2.1 ASTM Standards:
3.1 A specimen is melted at 60°C.
D1193 Specification for Reagent Water
3.2 Color is measured by tristimulus values of light trans-
mitted by a freshly melted specimen as percent of light
transmitted by distilled water. Convert the measured tristimu-
This test method is under the jurisdiction of ASTM Committee D16 on
lus values by appropriate equations to the platinum-cobalt
Aromatic, Industrial, Specialty and Related Chemicals and is the direct responsi-
bility of Subcommittee D16.02 on Oxygenated Aromatics.
scale.
Current edition approved Feb. 1, 2018. Published June 2018. DOI: 10.1520/
D8087-18
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 Available from U.S. Government Printing Office, Superintendent of
Standards volume information, refer to the standard’s Document Summary page on Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
the ASTM website. www.access.gpo.gov.
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D8087 − 18
3.3 Afterheatingfor2hat140°C,thecolorofthespecimen 6.4 Hydrochloric Acid (sp gr. 1.19)—Concentrated hydro-
is again measured by tristimulus values. Then convert the chloric acid (HCl).
measured tristimulus values by appropriate equations to the
6.5 Potassium Chloroplatinate, (K PtCl ).
2 6
platinum-cobalt scale.
6.6 Platimum-Cobalt Stock Solution—Dissolve 1.245 g of
potassium chloroplatinate (K PtCl ) and 1.00 g of cobalt
4. Significance and Use
2 6
chloride (CoCl ·6H O) in water. Carefully add 100 mL of
2 2
4.1 The color of maleic anhydride can be an indication of
hydrochloric acid (HCl sp gr 1.19) and dilute to 1 L with
the purity of these materials. A high color after heating
distilled water. The absorbance of the 500 platinum-cobalt
normally indicates contamination or decomposition.
stocksolutioninacellhavinga10-mmlightpathwithdistilled
4.2 This standard is suitable for process quality control and
water in a matched cell as the reference solution must fall
determining if the product meets specifications.
within the limits given in Table 1.
5. Apparatus
5.1 Instrument, with the following provision:
TABLE 1 Absorbance Tolerance Limits for No. 500 Platinum-
5.1.1 Instrument Sensor, shall provide a beam for illuminat-
Cobalt Stock Solution
ing the sample cell in transmission. The instrument shall be
Wavelength Absorbance
capable of converting light measured in total transmission
430 0.110 to 0.120
through the sample cell to CIE X Y Z tristimulus color values 455 0.130 to 0.145
480 0.105 to 0.120
for the measurement conditions of CIE illuminant C and the
510 0.055 to 0.065
CIE 1931 2 degree standard observer as described in Guide
E179 and Practice E308.
5.1.2 The CIE X Y Z tristimulus color values shall be
convertible to the instrumental yellowness index (YI) defined
6.7 Platinum-Cobalt Standards—From the stock solution
by Practice E308 and Practice E313. A correlation between
prepare color standards in accordance with Table 2 by diluting
measuredyellownessindex(YI)(PracticeE313)valuesandthe
the required volumes to 100 mL with water in volumetric
Pt-Co standard solutions shall be used to yield an equivalent
flasks. When properly sealed and stored these standards are
instrumental Pt-Co rating for liquid hydrocarbon samples.
stable for at least one year. 500 Platinum-Cobalt standards may
5.1.3 Sample Cells, shall have clear, colorless, parallel
also be purchased.
entrance and exit windows. The internal distance between the
faces shall be user selectable from 20 to 50 mm. When
7. Hazards
measuring samples using cells of the same path length, a path
7.1 Consult current OSHA regulations, suppliers’ Safety
length tolerance of 63 % or less is appropriate. Matched cells
Data Sheet, and local regulations for all materials used in this
are preferred but not required. Sample cells shall be high
test method.
temperature resistant.
5.1.4 Heated Bath or Oven—electric dry block or oven
7.2 Warning—When handling molten solids in open tubes,
capable of maintaining 60°C (61°C) and 140°C (61°C) and
adequate ventilation must be provided and proper protection
deep enough to completely maintain molten specimen in cell.
should be used to prevent thermal burns.
6. Reagents and Materials
8. Sampling and Handling
6.1 Purity of Reagent
...