ASTM D5153-91(1997)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D 5153 – 91 (Reapproved 1997)
Standard Test Method for
Palladium in Molecular Sieve Catalyst by Atomic
Absorption
This standard is issued under the fixed designation D 5153; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.2 This test method is not intended to cover samples
containing precious metals other than palladium.
1.1 This test method covers the determination of palladium
in molecular sieve-containing fresh catalysts with about 0.5
5. Apparatus
weight % of palladium.
5.1 Analytical Balance, capable of weighing to nearest 0.1
1.2 This standard does not purport to address all of the
mg.
safety concerns, if any, associated with its use. It is the
5.2 Atomic absorption spectrophotometer.
responsibility of the user of this standard to establish appro-
5.3 Beakers, TFE-fluorocarbon, 100-mL.
priate safety and health practices and determine the applica-
5.4 Crucibles, porcelain, 10-mL.
bility of regulatory limitations prior to use.
5.5 Crucible Cover, porcelain, for 10-mL crucible.
2. Referenced Documents 5.6 Desiccator.
5.7 Flasks, Erlenmeyer, 2000-mL.
2.1 ASTM Standards:
2 5.8 Graduated Cylinders, glass, 5-mL, 10-mL, 25-mL, 50-
D 1193 Specification for Reagent Water
mL, 250-mL, 500-mL, 1000-mL.
E 177 Practice for Use of the Terms Precision and Bias in
5.9 Graduated Cylinder, plastic, 10-mL.
ASTM Test Methods
5.10 Hot plate.
E 456 Terminology Relating to Quality and Statistics
5.11 Muffle furnace, electrically heated, capable of 1000°C.
E 691 Practice for Conducting an Interlaboratory Study to
5.12 Pipets, 4-mL, 6-mL, 8-mL, 10-mL.
Determine the Precision of a Test Method
5.13 Volumetric Flasks, 100-mL, 500-mL.
2.2 U.S. Federal Specification:
5.14 Watch glasses, TFE-fluorocarbon, for 100-mL beaker.
Federal Spec. NNN-P-395C Tolerance for Class A Pipets
5.15 Weighing Papers.
3. Summary of Test Method
6. Reagents and Materials
3.1 The test sample is treated with a mixture of sulfuric and
6.1 Purity of Reagents—Reagent grade chemicals shall be
hydrofluoric acids. Upon dissolution, the excess hydrofluoric
used in all tests. Unless otherwise indicated, it is intended that
acid is expelled. Aqua regia and lanthanum chloride are added
all reagents shall conform to the specifications of the Commit-
and the solution is diluted to a specific volume; and palladium
tee on Analytical Reagents of the American Chemical Society,
concentration is determined by atomic absorption spectropho-
where such specifications are available. Other grades may be
tometry. Absorbance of the samples is bracketed using a set of
used provided it is first ascertained that the reagent is of
narrow range, matrix matched standards. A second sample
sufficiently high purity to permit its use without lessening the
taken at the same time is used to determine loss on ignition.
accuracy of the determination.
4. Significance and Use
6.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean reagent water as defined
4.1 This test method provides a means of determining the
by Specification D 1193.
palladium content in fresh catalysts containing molecular
6.3 Hydrochloric acid, concentrated, 36.5–38.0 wt. % or 12
sieves.
M, sp gr 1.18.
6.4 Hydrofluoric acid, concentrated, 48.0–51.0 wt. % or
28.9 M, sp gr 1.17.
This test method is under the jurisdiction of ASTM Committee D-32 on
Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical
Composition.
Current edition approved July 15, 1991. Published September 1991.
2 5
Annual Book of ASTM Standards, Vol 11.01. “Reagent Chemicals, American Chemical Society Specifications,” American
Annual Book of ASTM Standards, Vol 14.02. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
Available from Standardization Documents Order Desk, Bldg. 4 Section D, 700 listed by the American Chemical Society, see “Analar Standards for Laboratory
Robbins Ave., Philadelphia, PA 19111-5094, ATTN: NPODS. U.K. Chemicals,” BDH Ltd., Poole, Dorset, and the “United States Pharmacopeia.”
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
D 5153
6.5 Nitric acid, concentrated, 69.0–71.0 wt. % or 15.7 M, sp 7.1.9 Add 5 mL of the lanthanum chloride solution to each
gr 1.41. flask. Dilute to volume when the solution has reached room
6.6 Sulfuric acid, concentrated, 95.0–98.0 wt. % or 18 M, sp temperature.
gr 1.84. 7.1.10 The concentration of palladium will be 0, 4, 6, 8 and
6.7 Aluminum Oxide (Al O ). 10 mg/L.
2 3
6.8 Lanthanum Chloride (LaCl ·7H O).
3 2
NOTE 4—The standard solutions are stable for two months.
6.9 Palladium Wire, 99.99 %.
7.2 Weighing—Prepare a carefully riffled, finely ground
6.10 Aqua Regia—Mix three parts by volume of concen-
sample of ambient-equilibrated catalyst. For example, the
trated hydrochloric acid (12 M) and one part by volume of
sample could be thinly spread on filter paper and exposed to
concentrated nitric acid (15.7 M) immediately before use.
room conditions for 16 h. The test method requires 7 to 10 g of
6.11 Sulfuric Acid, 15.8–16.3 wt. % or 3M—Cautiously add
sample. Samples for LOI and analysis shall be weighed at the
250 mL of concentrated sulfuric acid (18 M) to 1250 mL of
same time.
water—mix well and allow to cool.
7.2.1 For determination of percent loss on ignition at
6.12 Palladium Standard Solution, 500 mg/L—Dissolve
1000°C, ignite a porcelain crucible with lid at 1000°C for at
0.2500 g 6 0.0001 g of palladium wire (99.99 %) in 25 mL of
least 30 minutes, place in desiccator to cool and weigh to
aqua regia. Evaporate the solution to dryness on a steam bath.
nearest 0.1 mg. Transfer approximately 2.0 g of sample to the
Dissolve the remaining salts by addition of 25 mL of concen-
crucible and weigh to the nearest 0.1 mg with the lid in place.
trated hydrochloric acid (12 M) and 25 mL of distilled water.
7.2.2 For determination of palladium, transfer in triplicate
Transfer the solution to a 500 mL volumetric flask and dilute to
0.75 to 0.85 g of sample, weighed to the nearest 0.1 mg, into
volume when cool.
a 100-mL TFE-fluorocarbon beaker.
NOTE 1—A commercially available atomic absorption palladium refer-
7.3 Loss on Ignition:
ence solution may be u
...