ASTM D4607-94(2006)
(Test Method)Standard Test Method for Determination of Iodine Number of Activated Carbon
Standard Test Method for Determination of Iodine Number of Activated Carbon
SIGNIFICANCE AND USE
The iodine number is a relative indicator of porosity in an activated carbon. It does not necessarily provide a measure of the carbon’ ability to absorb other species. Iodine number may be used as an approximation of surface area for some types of activated carbons (see Test Method C 819). However, it must be realized that any relationship between surface area and iodine number cannot be generalized. It varies with changes in carbon raw material, processing conditions, and pore volume distribution (see Definitions D 2652).
The presence of adsorbed volatiles, sulfur; and water extractables may affect the measured iodine number of an activated carbon.
SCOPE
1.1 This test method covers the determination of the relative activation level of unused or reactivated carbons by adsorption of iodine from aqueous solution. The amount of iodine absorbed (in milligrams) by 1 g of carbon using test conditions listed herein is called the iodine number.
1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazard statements are given in Section 7.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D4607–94 (Reapproved 2006)
Standard Test Method for
Determination of Iodine Number of Activated Carbon
This standard is issued under the fixed designation D4607; 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 Circular 602—Testing of Glass Volumetric Apparatus
1.1 Thistestmethodcoversthedeterminationoftherelative
3. Summary of Test Method
activation level of unused or reactivated carbons by adsorption
3.1 This test method is based upon a three-point adsorption
of iodine from aqueous solution. The amount of iodine
isotherm (see Practices D3860). A standard iodine solution is
absorbed (in milligrams) by1gof carbon using test conditions
treated with three different weights of activated carbon under
listed herein is called the iodine number.
specifiedconditions.Thecarbontreatedsolutionsarefilteredto
1.2 This standard does not purport to address all of the
separate the carbon from the treated iodine solution (filtrate).
safety concerns, if any, associated with its use. It is the
Iodine remaining in the filtrate is measured by titration. The
responsibility of the user of this standard to establish appro-
amount of iodine removed per gram of carbon is determined
priate safety and health practices and determine the applica-
for each carbon dosage and the resulting data used to plot an
bility of regulatory limitations prior to use. Specific hazard
adsorption isotherm. The amount of iodine adsorbed (in
statements are given in Section 7.
milligrams) per gram of carbon at a residual iodine concentra-
2. Referenced Documents tion of 0.02 N is reported as the iodine number.
3.2 Iodine concentration in the standard solution affects the
2.1 ASTM Standards:
capacity of an activated carbon for iodine adsorption. There-
C819 Test Method for Specific Surface Area of Carbon or
fore, the normality of the standard iodine solution must be
Graphite
maintained at a constant value (0.100 6 0.001N) for all iodine
D1193 Specification for Reagent Water
number measurements.
D2652 Terminology Relating to Activated Carbon
3.3 The apparatus required consists of various laboratory
D2867 Test Methods for Moisture in Activated Carbon
glasswareusedtopreparesolutionsandcontactcarbonwiththe
D3860 Practice for Determination of Adsorptive Capacity
standard iodine solution. Filtration and titration equipment are
of Activated Carbon by Aqueous Phase Isotherm Tech-
also required.
nique
E11 SpecificationforWovenWireTestSieveClothandTest
4. Significance and Use
Sieves
4.1 The iodine number is a relative indicator of porosity in
E177 Practice for Use of the Terms Precision and Bias in
an activated carbon. It does not necessarily provide a measure
ASTM Test Methods
of the carbon’s ability to absorb other species. Iodine number
E287 Specification for Laboratory Glass Graduated Burets
may be used as an approximation of surface area for some
E288 Specification for Laboratory Glass Volumetric Flasks
types of activated carbons (see Test Method C819). However,
E300 Practice for Sampling Industrial Chemicals
it must be realized that any relationship between surface area
2.2 NIST Publication:
and iodine number cannot be generalized. It varies with
changes in carbon raw material, processing conditions, and
This test method is under the jurisdiction of ASTM Committee D28 on
pore volume distribution (see Definitions D2652).
ActivatedCarbonandisthedirectresponsibilityofSubcommitteeD28.02onLiquid
4.2 The presence of adsorbed volatiles, sulfur; and water
Phase Evaluation.
extractables may affect the measured iodine number of an
Current edition approved Oct. 1, 2006. Published November 2006. Originally
approved in 1986. Last previous edition approved in 1999 as D4607 – 94 (1999). activated carbon.
DOI: 10.1520/D4607-94R06.
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
Standards volume information, refer to the standard’s Document Summary page on Available from National Institute of Standards and Technology (NIST), 100
the ASTM website. Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D4607–94 (2006)
5. Apparatus Safety Data Sheet” (MSDS) for each reagent listed in Section
6 should be read and understood. Special precautions to be
NOTE 1—All volumetric measuring equipment should meet or exceed
taken during use of each reagent are included on the “Material
the requirements of NIST Circular 602. Volumetric glassware meeting
Safety Data Sheet” (MSDS). First aid procedures for contact
these specifications is generally designated as “Class A”. See also
with a chemical are also listed on its “MSDS.” A “Material
Specifications E287 and E288.
Safety Data Sheet” for each reagent may be obtained from the
5.1 Analytical Balance, accuracy 60.0001 g.
manufacturer. Other safety and health hazard information on
5.2 Buret, 10-mL capacity or 5-mL precision buret.
, ,
5 6 7
reagents used in this procedure is available.
5.3 Flasks, Erlenmeyer 250-mL capacity with ground glass
7.3 Careful handling and good laboratory technique should
stoppers.
always be used when working with chemicals. Avoid contact
5.4 Flask, Erlenmeyer wide-mouthed, 250-mL capacity.
with hydrochloric acid or acid vapor. Care should also be taken
5.5 Beakers, assorted sizes.
to prevent burns during heating of various solutions during this
5.6 Bottles, amber, for storage of iodine and thiosulfate
test procedure.
solutions.
7.4 Theuserofthistestmethodshouldcomplywithfederal,
5.7 Funnels, 100-mm top inside diameter.
state, and local regulations for safe disposal of all samples and
5.8 Filter Paper, 18.5-cm prefolded paper, Whatman No.
reagents used.
2V or equivalent.
5.9 Pipets, volumetric type, 5.0, 10.0, 25.0, 50.0, and
8. Preparation of Solutions
100.0-mL capacity.
8.1 Hydrochloric Acid Solution (5% by weight)—Add 70
5.10 Volumetric Flasks,1L.
mL of concentrated hydrochloric acid to 550 mL of distilled
5.11 Graduated Cylinders, 100 mL and 500 mL.
water and mix well. A graduated cylinder may be used for
measurement of volume.
6. Reagents
8.2 Sodium Thiosulfate (0.100 N)—Dissolve 24.820 g of
6.1 Purity of Reagents—Reagent grade chemicals shall be
sodium thiosulfate in approximately 75 6 25 mL of freshly
used in all tests. Unless otherwise indicated, it is intended that
boiled distilled water.Add 0.10 6 0.01 g of sodium carbonate
all reagents shall conform to the specifications of the Commit-
tominimizebacterialdecompositionofthethiosulfatesolution.
tee onAnalytical Reagents of theAmerican Chemical Society,
4 Quantitatively transfer the mixture to a 1-L volumetric flask
where such specifications are available. Other grades may be
and dilute to the mark. Allow the solution to stand at least 4
used, provided it is first ascertained that the reagent is of
days before standardizing. The solution should be stored in an
sufficiently high purity to permit its use without lessening the
amber bottle.
accuracy of the determination.
8.3 Standard Iodine Solution (0.100 6 0.001 N)—Weigh
6.2 Purity of Water—References to water shall be under-
12.700 g of iodine and 19.100 g of potassium iodide (KI) into
stood to mean reagent water conforming to Specification
a beaker. Mix the dry iodine and potassium iodide.Add 2 to 5
D1193 for Type II reagent water.
mLof water to the beaker and stir well. Continue adding small
6.3 Hydrochloric Acid, concentrated.
increments of water (approximately 5 mL each) while stirring
6.4 Sodium Thiosulfate, (Na S O·5H O).
2 2 3 2
until the total volume is 50 to 60 mL. Allow the solution to
6.5 Iodine, United States Pharmacopeia, resublimed crys-
stand a minimum of4hto ensure that all crystals are
tals.
thoroughly dissolved. Occasional stirring during this 4-h pe-
6.6 Potassium Iodide.
riod will aid in the dissolution. Quantitatively transfer to a 1-L
6.7 Potassium Iodate, primary standard.
volumetric flask and fill to the mark with distilled water. It is
6.8 Starch, soluble potato or arrowroot.
important that the standard iodine solution has an iodide-to-
6.9 Sodium Carbonate.
iodine weight ratio of 1.5 to 1. Store the solution in an amber
7. Hazards bottle.
8.4 Potassium Iodate Solution (0.1000 N)—Dry 4 or more
7.1 Severalpotentialhazardsareassociatedwithconducting
grams of primary standard grade potassium iodate (KIO)at
this test procedure. It is not the purpose of this standard to
110 65°Cfor2handcooltoroomtemperatureinadesiccator.
address all potential health and safety hazards encountered
Dissolve 3.5667 6 0.1 mg of the dry potassium iodate in about
with its use. The user is responsible for establishing appropri-
100 mL of distilled water. Quantitatively transfer to a 1-L
ate health and safety practices before use of this test procedure.
volumetric flask and fill to the mark with distilled water. Mix
Determine the applicability of federal and state regulations
thoroughly and store in a glass-stoppered bottle.
before attempting to use this test method.
8.5 Starch Solution—Mix 1.0 6 0.5 g of starch with 5 to 10
7.2 Personnel conducting the iodine number procedure
mL of cold water to make a paste. Add an additional 25 6 5
should be aware of potential safety and health hazards associ-
ated with the chemicals used in this procedure. The “Material
The “Chemical Safety Data Sheet” for the subject chemical is available from
the Manufacturing Chemists Association, Washington, DC.
4 6
“Reagent Chemicals,American Chemical Society Specifications,”Am. Chemi- Sax, N. I., Dangerous Properties of Industrial Materials , 4th edition, 1975,
cal Soc., Washington, DC. For suggestions on the testing of reagents not listed by Van Nostrand Reinhold Company, New York, NY.
theAmerican Chemical Society, see “Reagent Chemicals and Standards,” by Joseph NIOSH/OSHA Pocket Guide t
...
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