ASTM D2108-10(2020)

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: D2108 − 10 (Reapproved 2020)
Standard Test Method for
Color of Halogenated Organic Solvents and Their
Admixtures (Platinum-Cobalt Scale)
This standard is issued under the fixed designation D2108; 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 3.3 Digital Color Instrument—Digital color instruments are
available that measure color digitally and convert the result to
1.1 This test method covers the visual measurement of the
a numerical value using the Platinum-Cobalt scale. Many
color of halogenated organic solvents and their admixtures. It
manufacturers market instruments of this type.
is valid for values of 50 platinum-cobalt (Pt-Co) units or less.
NOTE 1—There are numerous colorimeters and comparators commer-
1.2 The values stated in SI units are to be regarded as cially available that measure the color of liquids and take some of the
subjectivity out of the measurement. These instruments may be calibrated
standard. No other units of measurement are included in this
with the platinum-cobalt color standards listed in Table 1 at 455 mm or
standard.
withopticallystandardizedcolorfilterdiskssuchasthoseavailableforthe
1.3 This standard does not purport to address all of the
Hellige Aqua Tester. Many of these instruments take the measurement
across a relatively narrow range of wave lengths, and their readings may
safety concerns, if any, associated with its use. It is the
be in error if the color of the sample is significantly different from the
responsibility of the user of this standard to establish appro-
amber color of the color standards.
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
4. Reagents
1.4 This international standard was developed in accor-
4.1 Purity of Reagents—Reagent grade chemicals shall be
dance with internationally recognized principles on standard-
used in all tests. Unless otherwise indicated, it is intended that
ization established in the Decision on Principles for the
all reagents shall conform to the specifications of the Commit-
Development of International Standards, Guides and Recom-
tee onAnalytical Reagents of theAmerican Chemical Society,
mendations issued by the World Trade Organization Technical
where such specifications are available. Other grades may be
Barriers to Trade (TBT) Committee.
used, provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
2. Significance and Use
accuracy of the determination.
2.1 Color may be indicative of the quality of the solvent
4.2 Purity of Water—Unless otherwise indicated, references
because any color present is due to the presence of contami-
to water shall be understood to mean distilled water or water of
nants.
equal purity.
3. Apparatus
4.3 Cobaltous Chloride—(CoCl ·6H O).
2 2
3.1 Color Comparison Tubes—Matched 50 mL or 100 mL,
4.4 Hydrochloric Acid (sp gr 1.19)—Concentrated hydro-
tall-form Nessler tubes, provided with ground-on, optically
chloric acid (HCl).
clear, glass caps.
4.5 Potassium Chloroplatinate—(K PtCl ).
2 6
3.2 Color Comparator—A color comparator constructed to
permit visual comparison of light transmitted through tall-
5. Preparation of Color Standards
form, Nessler tubes in the direction of their longitudinal axes.
5.1 Platinum-Cobalt Stock Solution—Dissolve 1.245 g of
The comparator should be constructed so that white light is
K PtCl and 1.000 g of CoCl ·6H O in water.Add 100 mLof
2 6 2 2
passed through or reflected off a white glass plate and directed
HCl (sp gr 1.19) and dilute to 1 Lwith water. This solution has
with equal intensity through the tubes and should be shielded
a color of 500.
so that no light enters the tubes from the side.
1 2
This test method is under the jurisdiction of ASTM Committee D26 on Reagent Chemicals, American Chemical Society Specifications, American
Halogenated Organic Solvents and Fire Extinguishing Agents and i
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