ASTM D3448-85(2000)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 3448 – 85 (Reapproved 2000)
Standard Test Method for
Specific Aqueous Conductance of Trichlorotrifluoroethane
This standard is issued under the fixed designation D3448; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 Conductivity Cell, dip-type. Cell constant of 0.1 recip-
rocal centimetre. Electrodes must be bright platinum.
1.1 This test method covers the determination of aqueous
4.3 Polyethylene Beaker, 250-mL.
conductivity due to ionizable contaminants extracted from
4.4 Polyethylene Bottles, wide mouth, 300-mLand 500-mL
trichlorotrifluoroethane. The value of 1.9 µS/cm as maximum
size.
specific aqueous conductance corresponds to 0.1 ppm of
4.4.1 Calibrate and mark the outside of the 300-mL poly-
chlorideion(100ppb).Itwascalculatedbyputtingthesolvent
ethylene bottles to indicate 20, 120, and 220 mL(graduate) of
specification of 0.1 ppm chloride into the equation of the
water volume, using deionized water to determine the liquid
subject method to find C − C equals 19.08. The specific
2 1
levels.
conductance due to contaminants from the solvent was then
4.5 Polyethylene Tubing, long enough to reach the bottom
calculated as follows:
of the 300-mL polyethylene bottle.
~C 2 C !C 5 ~19! ~0.1! 51.9µS/cm (1)
2 1 3
5. Reagents
1.2 The above is exclusive of the background specific
conductance of the water used in the analysis.
5.1 Purity of Reagents—Reagent grade chemicals shall be
1.3 This standard does not purport to address all of the
used in all tests. Unless otherwise indicated, it is intended that
safety concerns, if any, associated with its use. It is the
all reagents shall conform to the specifications of the Commit-
responsibility of the user of this standard to consult and
tee onAnalytical Reagents of theAmerican Chemical Society,
establish appropriate safety and health practices and deter-
where such specifications are available. Other grades may be
mine the applicability of regulatory limitations prior to use.
used, provided it is first ascertained that the reagent is of
Specific precautionary statements are given in Section 6.
sufficiently high purity to permit its use without lessening the
accuracy of the determination.
2. Summary of Test Method
5.2 Alcoholic Hydrochloric Acid (0.01 N)—Dilute 5.0 mL
2.1 Ionizable impurities in the solvent are extracted with
(pipet)ofconcentratedhydrochloricacidto6Lwithdenatured
water of known low conductivity. The increase in water
2B ethyl alcohol.
conductivity measures the amount of these impurities present.
5.3 Alumina Gel.
5.4 Deionized Trichloromonofluoromethane, in 50-lb cylin-
3. Significance and Use
der. This deionized solvent may be selected pure material or it
3.1 This test method allows for the determination of ioniz-
may be purified by multiple passes through an alumina gel
able contaminants (expressed in terms of ppb of HCl) in
contactor(seeFig.1).Checktheacceptabilityofthisdeionized
trichlorotrifluoroethane via measurement of specific aqueous
solvent as described in 7.4.
conductance.
NOTE 1—The use of deionized trichloromonofluoromethane will serve
3.2 This test method can be used for establishing manufac-
as a check on the cleanliness. The deionized standard should be used as
turing and purchasing specifications.
4. Apparatus 3
ModelCel-A01hasbeenfoundsatisfactoryandcanbeobtainedfromIndustrial
Instrument Inc., Cedar Grove, NJ. An equivalent may be used.
4.1 Conductivity Bridge.
Catalog No. H-4040, Harshaw Scientific Co., Cleveland, OH, has been found
satisfactory. An equivalent may be used.
Reagent Chemicals, American Chemical Society Specifications, American
This test method is under the jurisdiction of ASTM Committee D26 on
Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Halogenated Organic Solvents and Fire Extinguishing Agents and is the direct
listed by the American Chemical Society, see Analar Standards for Laboratory
responsibility of Subcommittee D26.04 on Test Methods.
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Current edition approved May 31, 1985. Published July 1985. Originally
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
published as D3448–75T. Last previous edition D3448–79.
MD.
Serfass Model RCM-15B1 has been found satisfactory and can be obtained
GradeF-3hasbeenfoundsatisfactoryandcanbeobtainedfromtheAluminum
from Industrial Instrument Inc., Cedar Grove, NJ. An equivalent may be used.
Company of America.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 3448
6.3 Hydrochloric Acid—Take all precautions necessary to
avoid contact with the body internally and externally.The acid
is corrosive.
7. Procedure
7.1 The basis of this test method is the determination by
conductance of ions present in the test solution. Therefore,
cleanallequipmentcarefullytoremovealladsorbedionsinthe
measuring apparatus, otherwise, erroneously high values will
be obtained. Do the initial cleaning and the cleaning of
equipment in accordance with 7.2. All equipment must be
rinsed with deionized trichloromonofluoromethane before us-
ing in a test.
7.2 Deionizing of Equipment:
7.2.1 Polyethylene Bottles and Stainless Steel Cylinders:
7.2.1.1 Add about 30 g of ion exchange resin from an
exchange cylinder to the item to be cleaned. Use an exchange
cylinder as a source of resin for cleaning.
7.2.1.2 Adddeionizedwatertothecontaineruntilitisabout
two-thirds full.
7.2.1.3 Closethecontainerandrollforatleast24honaball
mill roller or its equivalent.
7.2.1.4 Discardtheion-exchangeresinandwater,rinsewith
deionized water and then with deionized trichloromono-
fluoromethane.
7.2.2 Polyethylene Delivery Tubes:
NOTE 3—Use of highly plasticized polyethylene tubing and bottles is
not recommended.
FIG. 1 Alumina Gel Contractor
7.2.2.1 Place the polyethylene delivery tubes in a 500-mL
polyethylene bottle.
required on a periodic basis when samples are being evaluated. Standards
7.2.2.2 Clean by following 7.2.1.1-7.2.1.4.
should be checked whenever high values are obtained or there is doubt of
7.2.3 Polyethylene Beakers, Dip-Cell, and Other Equip-
the results.
ment:
5.5 Deionized Water—Distilled water passed through two
7.2.3.1 Add about 30 g of ion-exchange resin to the beaker.
mixed resin ion exchangers connected in series and having a
7.2.3.2 Fill the beaker with deionized water.
conductance of no greater than 0.5 µS. Check the acceptability
7.2.3.3 Stir, shake, or transfer the mixture from one con-
of the deionized water in accordance with 7.3. tainer to another for at least 2 min.
5.6 Ethyl Alcohol.
7.2.3.4 Discard the ion-exchange resin and deionized water
mixture.
NOTE 2—Specially denatured ethyl alcohol conforming to Formula
7.2.3.5 Rinse the equipment with deionized water and then
SD-2B of the U.S. Bureau of Internal Revenue may be substituted for
with deionized trichloromonofluoromethane before using in a
ethyl alcohol (95%).
test.
5.7 Hydrochloric Acid, concentrated.
7.3 Preparation of Deionized Water:
5.8 Ion-Exchange Cylinders.
7.3.1 Slowly pass distilled water through two mixed resin
ion exchangers, in series, immediately before use, into a clean
6. Safety Precautions
250-mL polyethylene beaker. (Note 4). Do not deionize water
6.1 Both trichlorotrifluoroethane and trichloromonofluoro-
and store, since it will adsorb carbon dioxide.
methane are not flammable and have threshold limit value’s of
NOTE 4—If the conductance of the water is greater than 0.5 µS, repeat
1000 ppm by volume in air. The respective boiling points of
the treatment and testing of the water until 0.5 µS or less is obtained,
thesesolventsareabout118and75°F(47.8and23.9°C).Avoid
rep
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