ASTM D6647-01(2011)
(Test Method)Standard Test Method for Determination of Acid Soluble Iron Via Atomic Absorption
Standard Test Method for Determination of Acid Soluble Iron Via Atomic Absorption
SIGNIFICANCE AND USE
In certain applications, such as acid purification, acidic food or chemical purification or decolorization, or other applications wherein iron may be leached out of the carbon, the use of acid-washed carbons will reduce or eliminate color pickup in the effluent or in the product. The acid soluble iron content is usually specified by the carbon supplier to prevent unacceptable levels of iron leach occurring.
Detection limits, sensitivity, and optimum ranges will vary with the models of atomic absorption spectrophotometers. General instrumental parameters are as follows:
Iron hollow cathode lamp.
Wavelength: 248.3 nm.
Fuel: acetylene (high purity).
Oxidant: air (from compressed air line, laboratory compressor, or a cylinder of compressed airall need to be clean and dry).
Type of flame: oxidizing.
The following lines may also be used:
248.8 nm Relative Sensitivity 2 271.9 nm Relative Sensitivity 4 302.1 nm Relative Sensitivity 5 252.7 nm Relative Sensitivity 6 372.0 nm Relative Sensitivity 10
The method, as written, is intended for carbons having an acid soluble iron content of 0.0030 to 0.050 % For carbons having higher iron contents, larger dilutions or smaller aliquots may be used.
The user should validate that there are no interferences from other metals in the sample matrix.
To prevent erroneous results, the user should ensure that no iron instruments contact any of the sample or the solutions used in this procedure. Only glass, ceramics, or plastic should be allowed to contact the sample or solutions.
SCOPE
1.1 This test method covers the determination of the acid soluble iron content of granular and powdered activated carbons, using an atomic absorption spectroscopy method by direct aspiration. Hydrochloric acid is used to extract the iron. This test method is not directly usable to determine the total iron concentration of a sample.
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. For a specific hazard statement, see Section 8.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D6647 − 01 (Reapproved 2011)
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
spectrometry, a sample is aspirated into a flame and atomized.
1.1 This test method covers the determination of the acid
A light beam is directed through the flame, into a
soluble iron content of granular and powdered activated
monochromator, and onto a detector that measures the amount
carbons, using an atomic absorption spectroscopy method by
of light absorbed by the atomized element in the flame.
direct aspiration. Hydrochloric acid is used to extract the iron.
Because each metal has its own characteristic absorption
This test method is not directly usable to determine the total
wavelength, a source lamp of that element is used.The amount
iron concentration of a sample.
of energy at the characteristic wavelength absorbed in the
1.2 This standard does not purport to address all of the
flame is proportional to the concentration of the element in the
safety concerns, if any, associated with its use. It is the
sample over a 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
ground until 95 % or more of the sample passes 325 mesh.The
2. Referenced Documents
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 Specification for Woven Wire Test Sieve Cloth and Test
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
use of acid-washed carbons will reduce or eliminate color
3. Terminology
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
5.2.1 Iron hollow cathode lamp.
Phase Evaluation.
Current edition approved Sept. 1, 2011. Published November 2011 Originally
5.2.2 Wavelength: 248.3 nm.
approved in 2001. Last previous edition approved in 2006 as D6647 – 01(2006).
5.2.3 Fuel: acetylene (high purity).
DOI: 10.1520/D6647-01R11.
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 (2011)
water. Allow to stand overnight. Quantitatively transfer the
248.8 nm Relative Sensitivity 2
271.9 nm Relative Sensitivity 4
solution into a one liter volumetric flask and dilute to the mark
302.1 nm Relative Sensitivity 5
with water. Mix thoroughly. This solution contains 0.1 mg. of
252.7 nm Relative Sensitivity 6
iron per ml.
372.0 nm Relative Sensitivity 10
5.3 The method, as written, is intended for carbons having
7.4 Standard Iron Solution II—Pipette 100.0 ml. of standard
an acid soluble iron content of 0.0030 to 0.050 % For carbons
iron solution I into a one liter volumetric flask. Dilute to the
having higher iron contents, larger dilutions or smaller aliquots
mark with water. Mix thoroughly. This solution contains 0.01
may be used.
mg. of iron/ml.
5.4 The user should validate that there are no interferences
NOTE 2—Commercially available iron solutions obtained from chemi-
from other metals in the sample matrix. calsupplyhouseshavebeenfoundtobeacceptable,providedtheaccuracy
of the solution meets specified requirements.
5.5 To prevent erroneous results, the user should ensure that
no iron instruments contact any of the sample or the solutions
8. Hazards
used in this procedure. Only glass, ceramics, or plastic should
8.1 Severalpotentialhazardsareassociatedwithconducting
be allowed to contact the sample or solutions.
this test procedure. It is not the purpose of this standard to
address all potential health and safety hazards associated with
6. Apparatus
its use. The user is responsible for establishing appropriate
6.1 Atomic absorption spectrometer , consisting of a light
healthandsafetypracticesandtodeterminetheapplicabilityof
source emitting the line spectrum of an element (see 5.2.1
any federal and state regulations before attempting to use this
above), a device for vaporizing the sample (usually a flame), a
test method.
means for isolating an absorption line (monochromator or filter
8.1.1 Since this procedure involves the use of hydrochloric
and adjustable slit—see 5.2.2 and 5.2.6 above), and a photo-
acid, all necessary personal protective equipment for handling
electric detector with its associated electronic amplifying and
acids should be used, including rubber gloves, lab apron, and
measuring equipment.
goggles. Careful handling and good laboratory technique
6.2 Beakers—Griffen, low form, 400 ml., Pyrex or equiva-
should always be used when working with chemicals. Avoid
lent.
contact with hydrochloric acid or acid vapor. Care should be
taken to prevent burns during handling of various solutions
6.3 Cylinder—ASTM, graduated, 100 ml.
during this test procedure.
6.4 Flask—Filtering, with side tube, 250 ml.
8.1.2 The atomic absorption spectrometer should be vented
6.5 Buchner Funnel—Size D, 71 mm. ID.
appropriately as recommended by the instrument manufacturer
to dissipate fumes and vapors generated by the combustion the
6.6 Filter Paper—Whatman No. 3, 7.0 cm. or equivalent.
flame.Thisprecautionprotectslaboratorypersonnelfromtoxic
6.7 Flasks—Volumetric, 50, 100. 250, 500, and 1000 ml.
vapors, protects the instrument from corrosive vapors, and
6.8 Pipettes—Volumetric, 1,2,5,10,25, and 100 ml.
prevents flame stability from being affected by room drafts.
8.1.3 The user of this test should comply with all federal,
6.9 325 Mesh Screen (U
...
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