ASTM D6647-01(2006)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:D6647–01 (Reapproved 2006)
Standard Test Method for
Determination of Acid Soluble Iron Via Atomic Absorption
This standard is issued under the fixed designation D6647; 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 3.1.1 atomic absorption—in flame atomic absorption spec-
trometry, a sample is aspirated into a flame and atomized. A
1.1 This test method covers the determination of the acid
light beam is directed through the flame, into a monochroma-
soluble iron content of granular and powdered activated
tor, and onto a detector that measures the amount of light
carbons, using an atomic absorption spectroscopy method by
absorbed by the atomized element in the flame. Because each
direct aspiration. Hydrochloric acid is used to extract the iron.
metal has its own characteristic absorption wavelength, a
This test method is not directly usable to determine the total
source lamp of that element is used. The amount of energy at
iron concentration of a sample.
the characteristic wavelength absorbed in the flame is propor-
1.2 This standard does not purport to address all of the
tional to the concentration of the element in the sample over a
safety concerns, if any, associated with its use. It is the
limited concentration range.
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. For a specific
4.1 Arepresentativesampleofthematerialtobeanalyzedis
hazard statement, see Section 8.
collected according to E300.Aknown weight of the sample is
2. Referenced Documents ground until 95 % or more of the sample passes 325 mesh.The
ground sample is oven dried, and then mixed with a dilute
2.1 ASTM Standards:
hydrochloric acid. The solution is boiled for 5 minutes to
D2652 Terminology Relating to Activated Carbon
convert the iron into a soluble chloride, and then cooled and
D1193 Specification for Reagent Water
filtered. The filter cake is washed with water. Then the filtrate
E11 SpecificationforWovenWireTestSieveClothandTest
is transferred quantitatively to a beaker. The concentration of
Sieves
iron in the filtrate is measured by atomic absorption against a
E177 Practice for Use of the Terms Precision and Bias in
set of standards. The acid soluble iron concentration is then
ASTM Test Methods
calculated against the weight of the original sample.
E287 Specification for Laboratory Glass Graduated Burets
E288 Specification for Laboratory Glass Volumetric Flasks
5. Significance and Use
E300 Practice for Sampling Industrial Chemicals
5.1 In certain applications, such as acid purification, acidic
2.2 NIST Publication:
3 food or chemical purification or decolorization, or other
Circular 602 Testing of Glass Volumetric Apparatus
applicationswhereinironmaybeleachedoutofthecarbon,the
3. Terminology use of acid-washed carbons will reduce or eliminate color
pickup in the effluent or in the product. The acid soluble iron
3.1 Definitions—Terms relating to this standard are defined
content is usually specified by the carbon supplier to prevent
in Terminology D2652.
unacceptable levels of iron leach occurring.
5.2 Detection limits, sensitivity, and optimum ranges will
vary with the models of atomic absorption spectrophotometers.
This test method is under the jurisdiction of ASTM Committee D28 on
General instrumental parameters are as follows:
ActivatedCarbonandisthedirectresponsibilityofSubcommitteeD28.02onLiquid
Phase Evaluation.
5.2.1 Iron hollow cathode lamp.
Current edition approved Oct. 1, 2006. Published November 2006 Originally
5.2.2 Wavelength: 248.3 nm.
approved in 2001. Last previous edition approved in 2001 as D6647 – 01. DOI:
5.2.3 Fuel: acetylene (high purity).
10.1520/D6647-01R06.
5.2.4 Oxidant: air (from compressed air line, laboratory
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
compressor, or a cylinder of compressed air—all need to be
Standards volume information, refer to the standard’s Document Summary page on
clean and dry).
the ASTM website.
3 5.2.5 Type of flame: oxidizing.
Available from National Institute of Standards and Technology (NIST), 100
Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov. 5.2.6 The following lines may also be used:
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D6647–01 (2006)
7.4 Standard Iron Solution II—Pipette100.0ml.ofstandard
248.8 nm Relative Sensitivity 2
271.9 nm Relative Sensitivity 4
iron solution I into a one liter volumetric flask. Dilute to the
302.1 nm Relative Sensitivity 5
mark with water. Mix thoroughly. This solution contains 0.01
252.7 nm Relative Sensitivity 6
mg. of iron/ml.
372.0 nm Relative Sensitivity 10
5.3 The method, as written, is intended for carbons having NOTE 2—Commercially available iron solutions obtained from chemi-
calsupplyhouseshavebeenfoundtobeacceptable,providedtheaccuracy
an acid soluble iron content of 0.0030 to 0.050 % For carbons
of the solution meets specified requirements.
having higher iron contents, larger dilutions or smaller aliquots
may be used.
8. Hazards
5.4 The user should validate that there are no interferences
8.1 Severalpotentialhazardsareassociatedwithconducting
from other metals in the sample matrix.
this test procedure. It is not the purpose of this standard to
5.5 To prevent erroneous results, the user should ensure that
address all potential health and safety hazards associated with
no iron instruments contact any of the sample or the solutions
its use. The user is responsible for establishing appropriate
used in this procedure. Only glass, ceramics, or plastic should
healthandsafetypracticesandtodeterminetheapplicabilityof
be allowed to contact the sample or solutions.
any federal and state regulations before attempting to use this
test method.
6. Apparatus
8.1.1 Since this procedure involves the use of hydrochloric
6.1 Atomic absorption spectrometer, consisting of a light
acid, all necessary personal protective equipment for handling
source emitting the line spectrum of an element (see 5.2.1
acids should be used, including rubber gloves, lab apron, and
above), a device for vaporizing the sample (usually a flame), a
goggles. Careful handling and good laboratory technique
means for isolating an absorption line (monochromator or filter
should always be used when working with chemicals. Avoid
and adjustable slit—see 5.2.2 and 5.2.6 above), and a photo-
contact with hydrochloric acid or acid vapor. Care should be
electric detector with its associated electronic amplifying and
taken to prevent burns during handling of various solutions
measuring equipment.
during this test procedure.
6.2 Beakers—Griffen, low form, 400 ml., Pyrex or equiva-
8.1.2 The atomic absorption spectrometer should be vented
lent.
appropriately as recommended by the instrument manufacturer
6.3 Cylinder—ASTM, graduated, 100 ml.
to dissipate fumes and vapors generated by the combustion the
6.4 Flask—Filtering, with side tube, 250 ml.
flame.Thisprecautionprotectslaboratorypersonnelfromtoxic
6.5 Buchner Funnel—Size D, 71 mm. ID.
vapors, protects the instrument from corrosive vapors, and
6.6 Filter Paper—Whatman No. 3, 7.0 cm. or equivalent.
prevents flame stability from being affected by room drafts.
6.7 Flasks—Volumetric, 50, 100. 250, 500, and 1000 ml.
8.1.3 The user of this test should comply with all federal,
6.8 Pipettes—Volumetric, 1,2,5,10,25, and 100 ml.
state, and local regulations for safe disposal of all samples and
6.9 325 Mesh Screen (U.S. Sieve series).
reagents used.
6.10 Analytical Balance, accuracy plus or minus 0.0001 g.
9. Sampling
6.11 Hot Plate.
9.1 Collect a representa
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