ASTM D5153-22

Standard Test Method for Palladium in Molecular Sieve Catalyst by Atomic Absorption Spectrophotometry

SIGNIFICANCE AND USE
4.1 This test method provides a means of determining the palladium content in fresh catalysts containing molecular sieves.  
4.2 This test method is not intended to cover samples containing precious metals other than palladium.
SCOPE
1.1 This test method covers the determination of palladium in molecular sieve-containing fresh catalysts with about 0.5 weight % of palladium.  
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.3 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jul-2022
• ICS: 71.040.30 - Chemical reagents
• Technical Committee: D32 - Catalysts
• Drafting Committee: D32.03 - Chemical Composition

Relations

• Refers: ASTM E456-13a(2022)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Apr-2022
• Refers: ASTM E1272-02(2019) - Standard Specification for Laboratory Glass Graduated Cylinders
• Effective Date: 01-Jan-2019
• Refers: ASTM E456-13A(2017)e3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E456-13A(2017)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E177-14 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2014
• Refers: ASTM E456-13ae2 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13a - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae3 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Aug-2013
• Refers: ASTM E177-13 - Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods
• Effective Date: 01-May-2013
• Refers: ASTM E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-2013
• Refers: ASTM E1272-02(2012) - Standard Specification for Laboratory Glass Graduated Cylinders
• Effective Date: 01-Nov-2012
• Refers: ASTM E456-12 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-May-2012
• Refers: ASTM E456-12e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-May-2012

Overview

ASTM D5153-22, titled "Standard Test Method for Palladium in Molecular Sieve Catalyst by Atomic Absorption Spectrophotometry," provides an established procedure for the quantitative determination of palladium in fresh catalysts containing molecular sieves. Developed by ASTM International, this test method utilizes atomic absorption spectrophotometry (AAS) to accurately measure palladium concentrations, ensuring reliable catalyst quality and consistency in industrial applications. The standard is specifically applicable to fresh catalysts with approximately 0.5% palladium by weight and does not apply to samples containing other precious metals.

Key Topics

• Scope of Application: Focuses on fresh molecular sieve catalysts containing palladium, especially those with a palladium content around 0.5% by weight.
• Test Methodology: The procedure requires the dissolution of catalyst samples using sulfuric and hydrofluoric acids, followed by dilution and treatment with aqua regia and lanthanum chloride. The resultant solution is analyzed by atomic absorption spectrophotometry, bracketing sample absorbance with matrix-matched standards.
• Precision and Accuracy: Interlaboratory studies have demonstrated strong repeatability and reproducibility, making the method reliable across qualified laboratories.
• Safety Considerations: The test involves hazardous materials, notably hydrofluoric acid (HF), which demands strict adherence to safety practices, including the use of appropriate fume hoods, personal protective equipment (PPE), and emergency preparedness for chemical exposure.

Applications

• Quality Assurance in Catalyst Manufacturing: Used widely by manufacturers of molecular sieve catalysts to monitor and control palladium loading during production, ensuring performance requirements are consistently met.
• Research and Development: Supports R&D activities involving new or modified catalyst formulations, allowing for precise determination of palladium content during evaluation phases.
• Industrial Catalyst Deployment: Assists chemical plants and refineries in confirming that catalyst batches meet specified palladium content before operational deployment, minimizing process variability.
• Regulatory Compliance and Documentation: Enables facilities to document compliance with internal and external specifications related to catalyst composition, contributing to reliable and traceable quality management systems.

Related Standards

• ASTM D1193 – Specification for Reagent Water: Defines the water quality required for analytical preparations in this method.
• ASTM D7442 – Practice for Sample Preparation of Fluid Catalytic Cracking Catalysts and Zeolites for Elemental Analysis: Offers complementary guidance on sample preparation steps.
• ASTM E177 – Practice for Use of the Terms Precision and Bias in ASTM Test Methods: Provides definitions and guidelines for interpreting test method performance.
• ASTM E456 – Terminology Relating to Quality and Statistics: Establishes terminology for quality assurance and statistical evaluation.
• ASTM E691 – Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method: Details protocols for precision assessment.
• U.S. Federal Spec. NNN-P-395C – Tolerance for Class A Pipets: Specifies requirements for pipets used in laboratory measurements.

Practical Value

Implementing ASTM D5153-22 helps ensure the reliable measurement of palladium in molecular sieve catalysts, which is vital for catalyst performance in sectors such as petrochemicals, environmental control, and fine chemicals. Accurate determination of palladium content assists organizations in meeting production targets, supporting product innovation, and maintaining compliance with industry standards. This standard also emphasizes laboratory safety and promotes consistent, high-quality analytical results across the catalyst industry.

Keywords: ASTM D5153, palladium determination, molecular sieve catalyst, atomic absorption spectrophotometry, catalyst quality, catalyst analysis, industrial standards, catalyst composition, laboratory safety, AAS method.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D5153 − 22
Standard Test Method for
Palladium in Molecular Sieve Catalyst by Atomic Absorption
Spectrophotometry
This standard is issued under the fixed designation D5153; 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 2.2 U.S. Federal Specification:
Federal Spec. NNN-P-395C Tolerance for Class A Pipets
1.1 This test method covers the determination of palladium
in molecular sieve-containing fresh catalysts with about 0.5
3. Summary of Test Method
weight % of palladium.
3.1 Warning—This test method requires the use of an
1.2 Units—The values stated in SI units are to be regarded
extremely hazardous substance, hydrofluoric acid. Please refer
as standard. No other units of measurement are included in this
to Appendix X1 and Appendix X2 for additional safety
standard.
requirements.
1.3 This standard does not purport to address all of the
3.2 The test sample is treated with a mixture of sulfuric and
safety concerns, if any, associated with its use. It is the
hydrofluoric acids. Upon dissolution, the excess hydrofluoric
responsibility of the user of this standard to establish appro-
acid is expelled.Aqua regia and lanthanum chloride are added
priate safety, health, and environmental practices and deter-
and the solution is diluted to a specific volume. Palladium
mine the applicability of regulatory limitations prior to use.
concentration is determined by atomic absorption spectropho-
1.4 This international standard was developed in accor-
tometry.Absorbance of the samples is bracketed using a set of
dance with internationally recognized principles on standard-
narrow range, matrix matched standards. A second sample,
ization established in the Decision on Principles for the
taken at the same time as the analysis sample, is used to
Development of International Standards, Guides and Recom-
determine loss on ignition.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents
4.1 This test method provides a means of determining the
palladium content in fresh catalysts containing molecular
2.1 ASTM Standards:
sieves.
D1193 Specification for Reagent Water
D7442 Practice for Sample Preparation of Fluid Catalytic
4.2 This test method is not intended to cover samples
CrackingCatalystsandZeolitesforElementalAnalysisby
containing precious metals other than palladium.
Inductively Coupled Plasma Optical Emission Spectros-
5. Apparatus
copy
E177 Practice for Use of the Terms Precision and Bias in
5.1 Analytical Balance, capable of weighing to nearest
ASTM Test Methods
0.1 mg.
E456 Terminology Relating to Quality and Statistics
5.2 Atomic Absorption Spectrophotometer.
E691 Practice for Conducting an Interlaboratory Study to
5.3 Beakers, TFE-fluorocarbon, 100 mL.
Determine the Precision of a Test Method
E1272 Specification for Laboratory Glass Graduated Cylin-
5.4 Crucibles, porcelain, 10 mL.
ders
5.5 Crucible Cover, porcelain, for 10 mL crucible.
This test method is under the jurisdiction of ASTM Committee D32 on 5.6 Desiccator.
Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical
5.7 Flasks, Erlenmeyer, 2000 mL.
Composition.
Current edition approved Aug. 1, 2022. Published August 2022. Originally
5.8 Graduated Cylinders, glass, 5 mL, 10 mL, 25 mL,
approved in 1991. Last previous edition approved in 2016 as D5153 – 10(2016).
50 mL, 250 mL, 500 mL, 1000 mL (see Specification E1272).
DOI: 10.1520/D5153-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on Available from Standardization Documents Order Desk, DODSSP, Bldg. 4,
the ASTM website. Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5153 − 22
5.9 Graduated Cylinder, plastic, 10 mL. trated hydrochloric acid (12 M) and 25 mL of distilled water.
Transferthesolutiontoa500mLvolumetricflaskanddiluteto
5.10 Hot Plate.
volume when cool.
5.11 Muffle Furnace, electrically heated, capable of
NOTE 2—A commercially available atomic absorption palladium refer-
1000 °C.
ence solution may be used if it is known to be reliable.
5.12 Pipets, 4 mL, 6 mL, 8 mL, 10 mL.
6.13 Lanthanum Chloride Solution—Dissolve 25.5 g of
5.13 Volumetric Flasks, 100 mL, 500 mL.
lanthanum chloride (LaCl ·7H O) in distilled water, dilute to
3 2
100 mL and mix well. This solution serves as an ionization
5.14 Watch Glasses, TFE-fluorocarbon, for 100 mL beaker.
suppressor in atomic absorption.
5.15 Weighing Papers.
6.14 Desiccant, molecular sieve, type 4A.
5.16 Fume Hood suitable for use with hydrofluoric acid.
7. Sampling
6. Reagents and Materials
7.1 Obtain a representative sample of approximately 10 g of
6.1 Purity of Reagents—Reagent grade chemicals shall be
material from larger composites by riffling or splitting in
used in all tests. Unless otherwise indicated, it is intended that
accordance with subsection 5.12 of STP 447A or some other
all reagents shall conform to the specifications of the Commit-
suitable means with the aim of obtaining a sample that
tee onAnalytical Reagents of theAmerican Chemical Society,
represents the composition of the larger composite.
where such specifications are available. Other grades may be
8. Procedure
used provided it is first ascertained that the reagent is of
sufficiently high purity to permit its use without lessening the
8.1 Preparation of Calibration Standards:
accuracy of the determination.
8.1.1 If the concentration of aluminum oxide in the sample
is unknown, digest a representative sample in acid and deter-
6.2 Purity of Water—Unless otherwise indicated, references
mine the aluminum concentration by atomic absorption spec-
to water shall be understood to mean reagent water as defined
trophotometry.
by Specification D1193.
8.1.2 Transfer 30 mL of sulfuric acid (3M) to five TFE-
6.3 Hydrochloric Acid, concentrated, 36.5–38.0 wt. % or 12
fluorocarbon beakers.
M, sp gr 1.18.
8.1.3 Toeachbeakeraddtheequivalentweightofaluminum
6.4 Hydrofluoric Acid, concentrated, 48.0–51.0 wt. % or
oxide that would be present in 0.8000 g of sample as
28.9 M, sp gr 1.17.
determined in 8.1.1.
NOTE 1—Refer to Section 8 of Practice D7442-08 for hazards associ-
NOTE 3—If it is available, 0.800 g of catalyst base material may be
ated with handling of acids.
substituted for the aluminum oxide.
6.5 Nitric Acid,concentrated,69.0–71.0wt.%or15.7M,sp
8.1.4 Transfer 0, 4, 6, 8 and 10 mL of the 500 mg/L
gr 1.41. palladium standard to the five TFE-fluorocarbon beakers.
8.1.5 Add 10 mL of concentrated hydrofluoric acid to each
6.6 Sulfuric Acid, concentrated, 95.0–98.0 wt. % or 18 M,
beaker.
sp gr 1.84.
8.1.6 Cover the beakers with TFE-fluorocarbon lids and
6.7 Aluminum Oxide (Al O ).
2 3
digest on a hot plate at medium heat until all solid material is
6.8 Lanthanum Chloride (LaCl ·7H O). in solution (including any brown stains that may appear on the
3 2
beaker walls) and light fumes are evolved.
6.9 Palladium Wire, 99.99 %.
NOTE 4—If brown stains do not redissolve, discard sample and prepare
6.10 Aqua Regia—Mix three parts by volume of concen-
again.
trated hydrochloric acid (12 M) and one part by volume of
8.1.7 Cool the solutions. Dilute to 70 mL with distilled
concentrated nitric acid (15.7 M) immediately before use.
water.Add 10 mLof aqua regia. Boil gently for a few minutes
6.11 Sulfuric Acid, 15.8–16.3 wt. % or 3M. Cautiously add
on a hot plate.
250 mL of concentrated sulfuric acid (18 M) to 1250 mL of
8.1.8 When the solution is cool, transfer quantitatively to a
water—mix well and allow to cool.
500 mL volumetric flask.
6.12 Palladium Standard Solution, 500 mg/L. Dissolve
8.1.9 Add 5 mL of the lanthanum chloride solution to each
0.2500 6 0.0001 g of palladium wire (99.99 %) in 25 mL of
flask. Dilute to volume when the solution has reached room
aqua regia. Evaporate the solution to dryness on a steam bath.
temperature.
Dissolve the remaining salts by addition of 25 mL of concen-
8.1.10 The concentration of palladium will be 0, 4, 6, 8 and
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D5153 − 10 (Reapproved 2016) D5153 − 22
Standard Test Method for
Palladium in Molecular Sieve Catalyst by Atomic Absorption
Spectrophotometry
This standard is issued under the fixed designation D5153; 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
1.1 This test method covers the determination of palladium in molecular sieve-containing fresh catalysts with about 0.5 weight
% of palladium.
1.2 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this
standard.
1.3 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D7442 Practice for Sample Preparation of Fluid Catalytic Cracking Catalysts and Zeolites for Elemental Analysis by Inductively
Coupled Plasma Optical Emission Spectroscopy
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
D7442E1272 Practice for Sample Preparation of Fluid Catalytic Cracking Catalysts and Zeolites for Elemental Analysis by
Inductively Coupled Plasma Optical Emission SpectroscopySpecification for Laboratory Glass Graduated Cylinders
2.2 U.S. Federal Specification:
Federal Spec. NNN-P-395C Tolerance for Class A Pipets
3. Summary of Test Method
3.1 Warning—This test method requires the use of an extremely hazardous substance, hydrofluoric acid. Please refer to Appendix
X1 and Appendix X2 for additional safety requirements.
This test method is under the jurisdiction of ASTM Committee D32 on Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical Composition.
Current edition approved Jan. 1, 2016Aug. 1, 2022. Published January 2016August 2022. Originally approved in 1991. Last previous edition approved in 20102016 as
D5153D5153 – 10–10.(2016). DOI: 10.1520/D5153-10R16.10.1520/D5153-22.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Available from Standardization Documents Order Desk, DODSSP, Bldg. 4, Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5153 − 22
3.2 The test sample is treated with a mixture of sulfuric and hydrofluoric acids. Upon dissolution, the excess hydrofluoric acid is
expelled. Aqua regia and lanthanum chloride are added and the solution is diluted to a specific volume. Palladium concentration
is determined by atomic absorption spectrophotometry. Absorbance of the samples is bracketed using a set of narrow range, matrix
matched standards. A second sample, taken at the same time as the analysis sample, is used to determine loss on ignition.
4. Significance and Use
4.1 This test method provides a means of determining the palladium content in fresh catalysts containing molecular sieves.
4.2 This test method is not intended to cover samples containing precious metals other than palladium.
5. Apparatus
5.1 Analytical Balance, capable of weighing to nearest 0.1 mg.
5.2 Atomic Absorption Spectrophotometer.
5.3 Beakers, TFE-fluorocarbon, 100-mL.100 mL.
5.4 Crucibles, porcelain, 10-mL.10 mL.
5.5 Crucible Cover, porcelain, for 10-mL10 mL crucible.
5.6 Desiccator.
5.7 Flasks, Erlenmeyer, 2000-mL.2000 mL.
5.8 Graduated Cylinders, glass, 5-mL, 10-mL, 25-mL, 50-mL, 250-mL, 500-mL, 1000-mL. 5 mL, 10 mL, 25 mL, 50 mL,
250 mL, 500 mL, 1000 mL (see Specification E1272).
5.9 Graduated Cylinder, plastic, 10-mL.10 mL.
5.10 Hot Plate.
5.11 Muffle Furnace, electrically heated, capable of 1000°C.1000 °C.
5.12 Pipets, 4-mL, 6-mL, 8-mL, 10-mL.4 mL, 6 mL, 8 mL, 10 mL.
5.13 Volumetric Flasks, 100-mL, 500-mL.100 mL, 500 mL.
5.14 Watch Glasses, TFE-fluorocarbon, for 100-mL100 mL beaker.
5.15 Weighing Papers.
5.16 Fume Hood suitable for use with hydrofluoric acid.
6. Reagents and Materials
6.1 Purity of Reagents—Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all
reagents shall conform to the specifications of the Committee on Analytical Reagents of the American Chemical Society, where
D5153 − 22
such specifications are available. 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.
6.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean reagent water as defined by
Specification D1193.
6.3 Hydrochloric Acid, concentrated, 36.5–38.0 wt. % or 12 M, sp gr 1.18.
6.4 Hydrofluoric Acid, concentrated, 48.0–51.0 wt. % or 28.9 M, sp gr 1.17.
NOTE 1—Refer to Section 8 of Practice D7442-08 for hazards associated with handling of acids.
6.5 Nitric Acid, concentrated, 69.0–71.0 wt. % or 15.7 M, sp gr 1.41.
6.6 Sulfuric Acid, concentrated, 95.0–98.0 wt. % or 18 M, sp gr 1.84.
6.7 Aluminum Oxide (Al O ).
2 3
6.8 Lanthanum Chloride (LaCl ·7H O).
3 2
6.9 Palladium Wire, 99.99 %.
6.10 Aqua Regia—Mix three parts by volume of concentrated hydrochloric acid (12 M) and one part by volume of concentrated
nitric acid (15.7 M) immediately before use.
6.11 Sulfuric Acid, 15.8–16.3 wt. % or 3M. Cautiously add 250 mL of concentrated sulfuric acid (18 M) to 1250 mL of water—mix
well and allow to cool.
6.12 Palladium Standard Solution, 500 mg/L. Dissolve 0.2500 6 0.0001 g of palladium wire (99.99 %) in 25 mL of aqua regia.
Evaporate the solution to dryness on a steam bath. Dissolve the remaining salts by addition of 25 mL of concentrated hydrochloric
acid (12 M) and 25 mL of distilled water. Transfer the solution to a 500 mL volumetric flask and dilute to volume when cool.
NOTE 2—A commercially available atomic absorption palladium reference solution may be used if it is known to be reliable.
6.13 Lanthanum Chloride Solution—Dissolve 25.5 g of lanthanum chloride (LaCl ·7H O) in distilled water, dilute to 100 mL and
3 2
mix well. This solution serves as an ionization suppressor in atomic absorption.
6.14 Desiccant, molecular sieve, type 4A.
7. Sampling
7.1 Obtain a representative sample of approximately 10 g of material from larger composites by riffling or splitting in accordance
with subsection 5.12 of STP 447A or some other suitable means with the aim of obtaining a sample that represents the
composition of the larger composite.
8. Procedure
8.1 Preparation of Calibration Standards:
Reagent Chemicals, American Chemical Society Specifications, American Chemical Society, Washington, DC. For Suggestions on the testing of reagents not listed by
the American Chemical Society, see Annual Standards for Laboratory Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia and National
Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville, MD.
Manual on Test Sieving Methods, ASTM STP 447A, ASTM International, 2005.
D5153 − 22
8.1.1 If the concentration of aluminum oxide in the sample is unknown, digest a representative sample in acid and determine the
aluminum concentration by atomic absorption spectrophotometry.
8.1.2 Transfer 30 mL of sulfuric acid (3M) to five TFE-fluorocarbon beakers.
8.1.3 To each beaker add the equivalent weight of aluminum oxide that would be present in 0.8000 g of sample as determined
in 7.1.18.1.1.
NOTE 3—If it is available, 0.800 g of catalyst base material may be substituted for the aluminum oxide.
8.1.4 Transfer 0, 4, 6, 8 and 10 mL of the 500 mg/L palladium standard to the five TFE-fluorocarbon beakers.
8.1.5 Add 10 mL of concentrated hydrofluoric acid to each beaker.
8.1.6 Cover the beakers
...