ASTM D4481-21

Standard Test Method for Total Nickel in Fresh Alumina-Base Catalysts

SIGNIFICANCE AND USE
4.1 This test method sets forth a procedure by which catalyst samples can be compared either on an interlaboratory or intralaboratory basis. It is anticipated that catalyst producers and users will find this method of value.
SCOPE
1.1 This test method covers the determination of nickel in fresh alumina-base catalysts and has been tested at nickel concentrations from 2.5 to 60 weight %, expressed as nickel oxide (NiO).  
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-May-2021
• 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 E456-13A(2017)e1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 01-Oct-2017
• Refers: ASTM E456-13A(2017)e3 - 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 E456-13a - 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 E456-13ae1 - Standard Terminology Relating to Quality and Statistics
• Effective Date: 15-Nov-2013
• Refers: ASTM E456-13ae2 - 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 E691-13 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-May-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 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
• Refers: ASTM E691-11 - Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
• Effective Date: 01-Nov-2011
• Refers: ASTM E105-10 - Standard Practice for Probability Sampling Of Materials
• Effective Date: 01-Oct-2010

Overview

ASTM D4481-21: Standard Test Method for Total Nickel in Fresh Alumina-Base Catalysts establishes a reliable and reproducible procedure for determining the nickel content, expressed as nickel oxide (NiO), in fresh alumina-based catalysts. Developed by ASTM International, this test method supports quality control for catalyst producers and users, enabling results comparison both within (intralaboratory) and between (interlaboratory) facilities. The method applies to nickel concentrations ranging from 2.5% to 60% by weight, ensuring broad applicability for catalyst manufacturing and quality assurance processes.

Key Topics

• Scope and Applicability

  • Determines total nickel as NiO in fresh alumina-base catalysts.
  • Suitable for nickel concentrations between 2.5 and 60 weight percent.
  • Results are stated in SI units, aligning with international measurement standards.

• Test Procedure Highlights

  • Catalyst samples are dissolved using concentrated hydrochloric acid; further treatment removes silica and allows for the precipitation of nickel using dimethylglyoxime.
  • Nickel is quantified by weighing its precipitate after drying.
  • Loss on ignition at 550°C is determined to ensure accuracy of the NiO percentage on a dry basis.

• Precision and Repeatability

  • Provides guidance on the repeatability and reproducibility of test results.
  • Enables comparison of test results from different laboratories, supporting industry-wide quality benchmarks.

• Safety Considerations

  • The method requires the handling of hazardous chemicals, notably hydrofluoric acid.
  • Strict adherence to laboratory safety, proper use of PPE, and fume hoods are mandatory.

Applications

The ASTM D4481-21 standard is instrumental for various stakeholders in the catalyst and refining industries, including:

• Catalyst Manufacturers

  • Ensures consistent production quality by quantifying nickel content in fresh catalysts.
  • Supports compliance with customer and regulatory requirements.

• Petrochemical and Refining Plants

  • Facilitates quality assurance of incoming catalysts.
  • Assists in the evaluation of catalyst performance, as nickel loading directly affects process outcomes.

• Research and Development

  • Provides a consistent methodology for comparing new catalyst formulations or process modifications.
  • Supports studies on catalyst activation and the role of nickel in catalytic performance.

• Quality Control and Laboratory Settings

  • Establishes an authoritative reference method suitable for internal audits, external certifications, and ISO-compliant laboratory practices.

Related Standards

The effectiveness of ASTM D4481-21 is enhanced by related ASTM standards that support sample preparation, terminology, and testing protocols:

• ASTM D1193 - Specification for Reagent Water: Ensures high-purity water for consistent test results.
• ASTM D7442 - Practice for Sample Preparation of Fluid Catalytic Cracking Catalysts and Zeolites for Elemental Analysis: Provides guidance for preparing catalyst samples before analysis.
• ASTM E105 - Guide for Probability Sampling of Materials: Useful for selecting representative samples from bulk materials.
• ASTM E177 - Practice for Use of the Terms Precision and Bias in ASTM Test Methods: Standardizes definitions for precision and bias reporting.
• ASTM E456 - Terminology Relating to Quality and Statistics: Provides definitions for quality-related terminology.
• ASTM E691 - Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method: Outlines procedures for collaborative studies on test method precision.

Practical Value

ASTM D4481-21 delivers a standardized, internationally recognized method for assessing the nickel content in alumina-based catalysts. This consistency in testing methodology underpins quality assurance throughout the catalyst supply chain, from manufacturing through to end-use in petrochemical processing. By following ASTM D4481-21 and its related standards, organizations can confidently verify catalyst specifications, benchmark results, and ensure compliance with both internal and regulatory expectations.

Keywords: ASTM D4481-21, total nickel determination, alumina-base catalysts, catalyst testing, nickel oxide, quality control, catalyst manufacturing, laboratory standards, petrochemical industry.

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: D4481 − 21
Standard Test Method for
Total Nickel in Fresh Alumina-Base Catalysts
This standard is issued under the fixed designation D4481; 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. Summary of Test Method
1.1 This test method covers the determination of nickel in 3.1 The test specimen (as received) is treated with concen-
fresh alumina-base catalysts and has been tested at nickel trated hydrochloric acid to solubilize the nickel. If necessary,
concentrations from 2.5 to 60 weight %, expressed as nickel
nickel is recovered from any insoluble residue by potassium
oxide (NiO). pyrosulfate fusion, after hydrofluoric-sulfuric acid treatment to
remove silica. Ammonium citrate is added to complex the
1.2 Units—The values stated in SI units are to be regarded
aluminum and buffer the solution. Nickel is precipitated as
as standard. No other units of measurement are included in this
nickel dimethylglyoxime, Ni (C H O N ) , at a weakly alka-
4 7 2 2 2
standard.
line pH. The precipitate is washed and weighed as Ni
1.3 This standard does not purport to address all of the
(C H O N ) after drying at 120 °C.
4 7 2 2 2
safety concerns, if any, associated with its use. It is the
3.2 A separate test specimen is taken to determine loss on
responsibility of the user of this standard to establish appro-
ignition (LOI) at 550 °C. The value is used to calculate the
priate safety, health, and environmental practices and deter-
nickel as percent nickel oxide (NiO) on a 550 °C dry basis.
mine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accor-
4. Significance and Use
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
4.1 This test method sets forth a procedure by which
Development of International Standards, Guides and Recom-
catalyst samples can be compared either on an interlaboratory
mendations issued by the World Trade Organization Technical
or intralaboratory basis. It is anticipated that catalyst producers
Barriers to Trade (TBT) Committee.
and users will find this method of value.
2. Referenced Documents
5. Interferences
2.1 ASTM Standards:
5.1 Cobalt, molybdenum, and aluminum do not interfere.
D1193 Specification for Reagent Water
Interferences by elements that precipitate as hydroxides, such
D7442 Practice for Sample Preparation of Fluid Catalytic
as iron, chromium, aluminum, lead, tin, manganese, titanium,
CrackingCatalystsandZeolitesforElementalAnalysisby
and zirconium, are avoided by the addition of ammonium
Inductively Coupled Plasma Optical Emission Spectros-
citrate before making the solutions ammoniacal. Copper, pres-
copy
ent in the 2 to 10 % range, tends to be co-precipitated with the
E105 Guide for Probability Sampling of Materials
nickel dimethylglyoxime. The only other metal ions precipi-
E177 Practice for Use of the Terms Precision and Bias in
tated by dimethylglyoxime are palladium, gold, and bismuth.
ASTM Test Methods
E456 Terminology Relating to Quality and Statistics
6. Apparatus
E691 Practice for Conducting an Interlaboratory Study to
6.1 Beakers, 600-mL, 150-mL.
Determine the Precision of a Test Method
6.2 Hotplate.
6.3 Furnace, electric muffle. Calibrated and capable of
This test method is under the jurisdiction of ASTM Committee D32 on
maintaining temperatures of 550 6 25 °C, and 950 6 25 °C.
Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical
Composition. 3
6.4 Platinum Dishes, 100-mL capacity.
Current edition approved June 1, 2021. Published June 2021. Originally
approved in 1985. Last previous edition approved in 2015 as D4481 – 10(2015).
6.5 Mortar and Pestle, agate, or equivalent mechanical
DOI: 10.1520/D4481-21.
grinder.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
6.6 Crucibles, sintered-glass, 30-mL, medium porosity frit.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 6.7 Fiberglass Filter, 3.2 cm.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4481 − 21
part of the procedure. The organic reagent, dimethylglyoxime, is not very
6.8 Drying Oven capable of maintaining a temperature of
soluble in water and is often added as a 1 % solution in ethanol. When
120 °C.
added in this way, some of the excess reagent may contaminate the
6.9 Vacuum Filtering Flask, 500-mL.
precipitated nickel complex. For this reason, an aqueous solution of the
sodium salt is preferred. If the alcohol solution of dimethylglyoxime is to
6.10 Filter Holder and Filter Disk, Millipore 0.65 µm-
be used, add an amount so that the alcohol content of the sample solution
47-mm diameter.
does not exceed 50 % or some of the precipitated nickel dimethylglyoxy-
mate may dissolve.
6.11 pH Paper to detect a value of 9.
6.12 Screen, 250-µm openings, 60-mesh.
8. Sampling
6.13 Analytical Balance, capable of weighing to nearest 0.1
8.1 The selection of a representative analytical sample from
mg.
the bulk material is outside the scope of the present test
method. It is presumed that parties using this test method for
6.14 Ashless Filter Pulp.
comparison purposes will have agreed on the selection of an
6.15 Desiccator.
analytical sample. If a sampling procedure is desired, Practice
6.16 Laboratory Fume Hood, suitable for use with Hydro-
E105 is recommended.
fluoric acid.
8.2 Grind the sample to pass through a 60-mesh screen.
Grind and screen the sample inside of a suitable laboratory
7. Reagents
fume hood. Avoid inhaling dust from the grinding and screen-
7.1 Purity of Reagents—Reagent grade chemicals shall be
ingstep. Nickel and its compounds are regulated bytheEPAas
used in all tests. Unless otherwise indicated, it is intended that
possible carcinogens. For more information, go to EPA.gov for
all reagents shall conform to the specifications of the Commit-
a list of extremely hazardous substances. Consult a material
tee onAnalytical Reagents of theAmerican Chemical Society,
safety data sheet for additional information.
where such specifications are available. Other grades may be
used, provided it is first ascertained that the reagent is of
9. Procedure
sufficiently high purity to permit its use without lessening the
9.1 Warning—This test method requires the use of an
accuracy of the determination.
Extremely Hazardous substance, Hydrofluoric acid (HF). Ad-
7.2 Purity of Water—Unless otherwise indicated, references
ditional information for the safe handling of this chemical, HF,
to water shall be understood to mean type IV reagent water as
is included as Appendix X1. Read Appendix X1 and assemble
defined in Specification D1193.
thenecessarysafetyequipmentbeforeproceedingwiththistest
7.3 Ammonium Citrate, dibasic crystal, (NH ) HC H O .
4 2 6 5 7 method. Warning—All heating of acidsolutionsonahotplate
or with a gas burner should be conducted in a fume hood.
7.4 Ammonium Hydroxide, 10 and 25 % solutions.
Fusions on a gas burner should be conducted in a fume hood.
NOTE 1—Refer to Section 8 on Hazards in Practice D7442 for hazards
9.2 Weigh three test specimens sufficient to yield 50 to 75
associated with handling of acids.
mg of NiO into 150-mL beakers. Record mass to the nearest
7.5 Hydrochloric Acid, concentrated 38 %.
0.1 mg as G.
7.6 Hydrofluoric Acid, concentrated 48 %.
9.3 Weigh three 1-g test specimens into platinum dishes or
7.7 Methyl Red Indicator (o-carboxy benzene
porcelain crucibles. Record mass to the nearest 0.1 mg as G .
azodimethylaniline)—Dissolve 0.02 g in 60-mL reagent grade
Calcine for2hina550°C muffle furnace. Transfer to a
ethanol. Add 40.0 mL of distilled water.
desiccator containing freshly activated 4A molecular sieve.
Cool, weigh, record mass as G , and calculate percent solids.
7.8 4A Molecular Sieve, activated for2hat275°C.
7.9 Potassium Hydrogen Sulfate, fused power-acid-flux 9.4 To test specimens from 9.2, add 20-mL of concentrated
hydrochloric acid and heat gently on a hotplate until only a
grade.
paste of solids is left. Do not boil the solution. Do not bake
7.10 Sodium Dimethylglyoxime, 8-Hydrate, crystal,
solids or subsequent re-solution will be difficult.
CH C:NONaC:NONaCH ·8H O. Prepare a 1 weight % per
3 3 2
volume solution in water. 9.5 Add 20 mLof concentrated hydrochloric acid and warm
on a hotplate 15 to 30 min to dissolve salts. Cool and dilute to
7.11 Sulfuric Acid, 10 and 50 % solutions.
about 100 mL with deionized water.
NOTE 2—The sodium salt of dimethylglyoxime is recommended, rather
9.6 Filter solids on 0.45-µm filter, using a 500-mL filter
than the organic reagent, dimethylglyoxime because the salt is water
flask as a receiver. Wash the beaker with four approximately
soluble. Large excesses added to precipitate the nickel do no ha
...

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: D4481 − 10 (Reapproved 2015) D4481 − 21
Standard Test Method for
Total Nickel in Fresh Alumina-Base Catalysts
This standard is issued under the fixed designation D4481; 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 nickel in fresh alumina-base catalysts and has been tested at nickel concentrations
from 2.5 to 60 weight %, expressed as nickel oxide (NiO).
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 its 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
E105 Guide for Probability Sampling of Materials
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
3. Summary of Test Method
3.1 The test specimen (as received) is treated with concentrated hydrochloric acid to solubilize the nickel. If necessary, nickel is
recovered from any insoluble residue by potassium pyrosulfate fusion, after hydrofluoric-sulfuric acid treatment to remove silica.
Ammonium citrate is added to complex the aluminum and buffer the solution. Nickel is precipitated as nickel dimethylglyoxime,
Ni (C H O N ) , at a weakly alkaline pH. The precipitate is washed and weighed as Ni (C H O N ) after drying at 120°C.120 °C.
4 7 2 2 2 4 7 2 2 2
3.2 A separate test specimen is taken to determine loss on ignition (LOI) at 550°C.550 °C. The value is used to calculate the nickel
as percent nickel oxide (NiO) on a 550°C550 °C dry basis.
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 Dec. 1, 2015June 1, 2021. Published December 2015June 2021. Originally approved in 1985. Last previous edition approved in 20102015 as
D4481D4481 – 10–10.(2015). DOI: 10.1520/D4481-10R15.10.1520/D4481-21.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D4481 − 21
4. Significance and Use
4.1 This test method sets forth a procedure by which catalyst samples can be compared either on an interlaboratory or
intralaboratory basis. It is anticipated that catalyst producers and users will find this method of value.
5. Interferences
5.1 Cobalt, molybdenum, and aluminum do not interfere. Interferences by elements that precipitate as hydroxides, such as iron,
chromium, aluminum, lead, tin, manganese, titanium, and zirconium, are avoided by the addition of ammonium citrate before
making the solutions ammoniacal. Copper, present in the 2 to 10 % range, tends to be co-precipitated with the nickel
dimethylglyoxime. The only other metal ions precipitated by dimethylglyoxime are palladium, gold, and bismuth.
6. Apparatus
6.1 Beakers, 600-mL, 150-mL.
6.2 Hotplate.
6.3 Furnace, electric muffle. Calibrated and capable of maintaining temperatures of 550 6 25°C,25 °C, and 950 6 25°C.25 °C.
6.4 Platinum Dishes, 100-mL capacity.
6.5 Mortar and Pestle, agate, or equivalent mechanical grinder.
6.6 Crucibles, sintered-glass, 30-mL, medium porosity frit.
6.7 Fiberglass Filter, 3.2 cm.
6.8 Drying Oven capable of maintaining a temperature of 120°C.120 °C.
6.9 Vacuum Filtering Flask, 500-mL.
6.10 Filter Holder and Filter Disk, Millipore 0.65 μm-47-mm diameter.
6.11 pH Paper to detect a value of 9.
6.12 Screen, 250-μm openings, 60-mesh.
6.13 Analytical Balance, capable of weighing to nearest 0.1 mg.
6.14 Ashless Filter Pulp.
6.15 Desiccator.
6.16 Laboratory Fume Hood, suitable for use with Hydrofluoric acid.
7. Reagents
7.1 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
D4481 − 21
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.
7.2 Purity of Water—Unless otherwise indicated, references to water shall be understood to mean type IV reagent water as defined
in Specification D1193.
7.3 Ammonium Citrate, dibasic crystal, (NH ) HC H O .
4 2 6 5 7
7.4 Ammonium Hydroxide, 10 and 25 % solutions.
NOTE 1—Refer to Section 8 on Hazards in Practice D7442 for hazards associated with handling of acids.
7.5 Hydrochloric Acid, concentrated 38 %.
7.6 Hydrofluoric Acid, concentrated 48 %.
7.7 Methyl Red Indicator (o-carboxy benzene azodimethylaniline)—Dissolve 0.02 g in 60-mL reagent grade ethanol. Add 40.0 mL
of distilled water.
7.8 4A Molecular Sieve, activated for 2 h at 275°C.275 °C.
7.9 Potassium Hydrogen Sulfate, fused power-acid-flux grade.
7.10 Sodium Dimethylglyoxime, 8-Hydrate, crystal, CH C:NONaC:NONaCH ·8H O. Prepare a 1 weight % per volume solution
3 3 2
in water.
7.11 Sulfuric Acid, 10 and 50 % solutions.
NOTE 2—The sodium salt of dimethylglyoxime is recommended, rather than the organic reagent, dimethylglyoxime because the salt is water soluble.
Large excesses added to precipitate the nickel do no harm as the excess dimethylglyoxime is eliminated during the filtration and washing part of the
procedure. The organic reagent, dimethylglyoxime, is not very soluble in water and is often added as a 1 % solution in ethanol. When added in this way,
some of the excess reagent may contaminate the precipitated nickel complex. For this reason, an aqueous solution of the sodium salt is preferred. If the
alcohol solution of dimethylglyoxime is to be used, add an amount so that the alcohol content of the sample solution does not exceed 50 % or some of
the precipitated nickel dimethylglyoxymate may dissolve.
8. Sampling
8.1 The selection of a representative analytical sample from the bulk material is outside the scope of the present test method. It
is presumed that parties using this test method for comparison purposes will have agreed on the selection of an analytical sample.
If a sampling procedure is desired, Practice E105 is recommended.
8.2 Grind the sample to pass through a 60-mesh screen. Grind and screen the sample inside of a suitable laboratory fume hood.
Avoid inhaling dust from the grinding and screening step. Nickel and its compounds are regulated by the EPA as possible
carcinogens. For more information, go to EPA.gov for a list of extremely hazardous substances. Consult a material safety data sheet
for additional information.
9. Procedure
9.1 Warning—This test method requires the use of an Extremely Hazardous substance, Hydrofluoric acid (HF). Additional
information for the safe handling of this chemical, HF, is included as Appendix X1. Read Appendix X1 and assemble the necessary
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.
D4481 − 21
safety equipment before proceeding with this test method. Warning—All heating of acid solutions on a hot plate or with a gas
burner should be conducted in a fume hood. Fusions on a gas burner should be conducted in a fume hood.
9.2 Weigh three test specimens sufficient to yield 50 to 75 mg of NiO into 150-mL beakers. Record mass to the nearest 0.1 mg
as G.
9.3 Weigh three 1-g test specimens into platinum dishes or porcelain crucibles. Record mass to the nearest 0.1 mg as G . Calcine
for 2 h in a 550°C550 °C muffle furnace. Transfer to a desiccator containing freshl
...