ASTM D4548-91(2002)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4548–91(Reapproved2002)
Standard Test Method for
Anion-Cation Balance of Mixed Bed Ion-Exchange Resins
This standard is issued under the fixed designation D4548; 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 3.2.3 ion-exchange material,, n—an insoluble material that
has the ability to exchange reversibly certain ions in its
1.1 This test method determines the ratio between the
structure or attached to its surface as functional groups with
equivalents of anion-exchange capacity and the equivalents of
ions in a surrounding medium.
cation-exchange capacity present in a physical mixture of
3.2.4 ion-exchange resin,, n—a synthetic organic ion-
salt-splitting anion-exchange material and salt-splitting cation-
exchange material.
exchange material.
3.2.5 mixed bed,, n—a physical mixture of anion-exchange
1.2 The values stated in SI units are to be regarded as the
material and cation-exchange material.
standard.
3.2.6 salt-splitting,, adj—the ability of anion-exchange or
1.3 This standard does not purport to address all of the
cation-exchange materials to exchange hydroxide or hydrogen
safety concerns, if any, associated with its use. It is the
ions respectively for the ions in neutral salts.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Test Method
bility of regulatory limitations prior to use.
4.1 This test method consists of simultaneous conversion of
2. Referenced Documents the cation-exchange component to the hydrogen form and the
anion-exchange component to the chloride form with hydro-
2.1 ASTM Standards:
chloric acid. After rinsing to remove the excess acid, the
D1129 Terminology Relating to Water
hydrogen ion from the cation resin and the chloride ion from
D1193 Specification for Reagent Water
the anion resin are simultaneously eluted with neutral sodium
D2187 Test Methods for Physical and Chemical Properties
nitrate, and the amount eluted is determined by titration of the
of Particulate Ion-Exchange Resins
effluent for both ions.
3. Terminology
5. Significance and Use
3.1 Definitions—For definitions of terms used in this test
5.1 This test method is applicable to the analysis of new
method, refer to Terminology D1129.
materials that are sold as mixtures and to samples taken from
3.2 Definitions of Terms Specific to This Standard:
regenerableunitscontainingmixturesofanion-exchangingand
3.2.1 anion-exchange material,, n—an ion-exchange mate-
cation-exchangingmaterials.Itisusedtodeterminetheratioof
rial capable of the reversible exchange of negatively charged
the components without separating them from each other.
ions.
5.2 This test method is intended for mixtures of ion-
3.2.2 cation-exchange material,, n—an ion-exchange mate-
exchange materials that have salt-splitting capacity as mea-
rial capable of the reversible exchange of positively charged
sured by Test Method E of Test Methods D2187 for cation-
ions.
exchangeresins,andTestMethodHforanion-exchangeresins.
In the case of cation-exchange resins, these are styrene-based
This test method is under the jurisdiction of ASTM Committee D19 on Water
polymers with sulfonic acid functional groups. The anion-
and is the direct responsibility of Subcommittee D19.08 on Membranes and Ion
exchanging materials in this class are styrene-based materials
Exchange Materials.
withquaternaryammoniumfunctionalgroups.Thetestmethod
Current edition approved June 15, 1991. Published February 1992. Originally
published as D4548 – 86. Last previous edition D4548 – 86. DOI: 10.1520/D4548-
will determine the amount of anion-exchange material of any
91R02.
functionality present in the mixture. However, when anionic
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
groups that are not salt-splitting are present, the values for
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
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D4548–91 (2002)
tee onAnalytical Reagents of theAmerican Chemical Society.
Other grades may be used, provided it is first ascertained that
the reagent is of sufficiently high purity to permit its use
without lessening the accuracy of the determination.
7.2 Purity of Water—Unless otherwise indicated, reference
to water shall be understood to mean reagent water, conform-
ing to Specification D1193, Type IV.
7.3 Ammonium Hydroxide (1 + 9)—Pour 1 vol of ammo-
nium hydroxide (sp gr 0.90) into 9 vol of water and mix well.
7.4 Hydrochloric Acid (1 + 9)—Carefully pour 100 mL of
hydrochloric acid (sp gr 1.19) into 500 mL of water, stirring
constantly. Cool to 25 6 5°C and dilute to 1 L.
7.5 Isopropyl Alcohol, neutral.
7.6 Methyl Orange Indicator Solution (0.5 g/L)—Dissolve
0.05 g of methyl orange in water and dilute to 100 mL with
water.
FIG. 1 Typical Arrangement of Apparatus for Salt-Splitting
7.7 Nitric Acid (1 + 9)—Pour 1 vol of nitric acid (sp gr
Capacity
1.42) into 9 vol of water and mix thoroughly.
7.8 Phenolphthalein Indicator Solution (5.0 g/L)—Dissolve
cationic groups will be high due to the acidic character of the
0.5 g of phenolphthalein in 50 mL of 95 % ethanol (see Note
anion effluent. Cationic groups that do not split salts are not
1). Transfer to a volumetric flask and dilute to 100 mL with
measured.
water.
5.3 Samples are analyzed in this test method as received. It
NOTE 1—Isopropyl alcohol or specially denatured ethyl alcohol con-
is not necessary that the cation-exchanging resin be in the
forming to Formula 3A or 30 of the US Bureau of Internal Revenue may
hydrogen form and the anion-exchanging resin be in the
be substituted for 95 % alcohol.
hydroxide form for this test method.
5.4 This test method may be used to determine if new
7.9 Potassium Chromate Solution (50 g/L)—Dissolve 5.0 g
materials are balanced to meet their specification values. In
of potassium chromate in 50 mL of water. Dilute to 100 mL
operating regenerable units, it may be used to determine if the
with water.
components are separating properly or remixing properly. It
7.10 Silver Nitrate Solution, Standard (0.10 N)—Dry crys-
may also be used to check for improper balance in bedding or
talline silver nitrate at 105°C for 1 h and cool in a desiccator.
for loss of a component during operation.
Weigh out 176 0.05 g ofAgNO . Transfer to a 1-Lvolumetric
5.5 This test method begins with the conversion to the
flask with water. Dissolve in 500 mL of water. Dilute to 1-L
hydrogen and chloride forms. However, it may be combined
with water at 25 6 5°C and mix well. Store the solution in a
with the determination of the residual chloride and sulfate sites
tightly stoppered amber glass bottle.
by elution with sodium nitrate as described in Test Methods J
7.10.1 To standardize, dry approximately5gof sodium
and L in Test Methods D2187. In such cases the hydrogen ion
chloride in a glass container at 105°C for 2 h. Cool in a
as well as the chloride ion is determined in the second sodium
desiccator. Weigh accurately three 0.25 6 0.01 g portions of
nitrate elution described in Test Method I of Test Methods
the dried NaCl and transfer to separate 250 mL conical flasks.
D2187, and the calculations given herein are made using the
Add 100 mL of water and dissolve the NaCl. Add 1 mL of
titration values so determined.
K CrO solution (50 g/L) and titrate with the 0.1 N AgNO
2 4 3
standard solution with vigorous swi
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