ASTM D3943-21

Standard Test Method for Total Molybdenum 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 molybdenum in alumina-base catalysts and has been cooperatively tested at molybdenum concentrations from 8 to 18 weight %, expressed as MoO3. Any component of the catalyst other than molybdenum such as iron, tungsten, etc., which is capable of being oxidized by either ferric or ceric ions after being passed through a zinc-amalgam reductor column (Jones reductor) will interfere.  
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 Many catalysts that contain molybdenum also contain other metals, nickel for example, that may be regulated by the EPA. Go to the material safety data sheet for the catalyst material being analyzed. More information can be found at EPA.gov. Additional information on nickel containing catalysts can be found in Test Method D4481.  
1.4 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.  
1.5 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

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: D3943 − 21
Standard Test Method for
1
Total Molybdenum in Fresh Alumina-Base Catalysts
This standard is issued under the fixed designation D3943; 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 D4481 Test Method for Total Nickel in FreshAlumina-Base
Catalysts
1.1 This test method covers the determination of molybde-
D7442 Practice for Sample Preparation of Fluid Catalytic
num in alumina-base catalysts and has been cooperatively
CrackingCatalystsandZeolitesforElementalAnalysisby
tested at molybdenum concentrations from 8 to 18 weight %,
Inductively Coupled Plasma Optical Emission Spectros-
expressed as MoO . Any component of the catalyst other than
3
copy
molybdenum such as iron, tungsten, etc., which is capable of
E173 Practice for Conducting Interlaboratory Studies of
being oxidized by either ferric or ceric ions after being passed
Methods for Chemical Analysis of Metals (Withdrawn
through a zinc-amalgam reductor column (Jones reductor) will
3
1998)
interfere.
E507 Test Method for Determination of Aluminum in Iron
1.2 Units—The values stated in SI units are to be regarded
Ores by Flame Atomic Absorption Spectrometry
as standard. No other units of measurement are included in this
standard.
3. Summary of Test Method
1.3 Many catalysts that contain molybdenum also contain
3.1 The catalyst is digested in hot sulfuric acid to dissolve
other metals, nickel for example, that may be regulated by the
molybdenum, destroy organic matter, and to expel nitrates if
EPA. Go to the material safety data sheet for the catalyst
present. The acid solution is diluted and passed through an
material being analyzed. More information can be found at
amalgamated zinc column (Jones reductor) into a receiving
EPA.gov.Additionalinformationonnickelcontainingcatalysts
flask containing an excess of ferric ammonium sulfate. The
+6
can be found in Test Method D4481.
column quantitatively reduces the molybdenum (Mo to
+3
Mo ) which in turn is reoxidized in the receiving flask
1.4 This standard does not purport to address all of the
according to the reaction:
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- 13 13 16 12
Mo 13Fe →Mo 13Fe (1)
priate safety, health, and environmental practices and deter-
+3
3.2 The ferrous ion produced (three per Mo oxidized) is
mine the applicability of regulatory limitations prior to use.
titrated with standard ceric sulfate solution in the presence of
1.5 This international standard was developed in accor-
ferroin indicator. The indicator undergoes a color change (pink
dance with internationally recognized principles on standard-
to colorless or very faint blue-green) in the presence of excess
ization established in the Decision on Principles for the
+2
ceric ion. The amount of Fe titrated in the reaction:
Development of International Standards, Guides and Recom-
12 14 13 13
Fe 1Ce →Fe 1Ce (2)
mendations issued by the World Trade Organization Technical
+6
is a direct measure of Mo concentration.
Barriers to Trade (TBT) Committee.
4. Significance and Use
2. Referenced Documents
2
4.1 This test method sets forth a procedure by which
2.1 ASTM Standards:
catalyst samples can be compared either on an interlaboratory
D1193 Specification for Reagent Water
or intralaboratory basis. It is anticipated that catalyst producers
and users will find this method of value.
1
This test method is under the jurisdiction of ASTM Committee D32 on
Catalysts and is the direct responsibility of Subcommittee D32.03 on Chemical
5. Interferences
Composition.
5.1 Elements such as As, Sb, Cr, Fe, Ti, V, U, or W can
Current edition approved June 1, 2021. Published June 2021. Originally
approved in 1980. Last previous edition approved in 2015 as D3943 – 10(2015).
interfere in this analysis. If serious interference occurs, it will
DOI: 10.1520/D3943-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on The last approved version of this historical standard is referenced on
the ASTM website. www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3943 − 21
be necessary to isolate t
...

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: D3943 − 10 (Reapproved 2015) D3943 − 21
Standard Test Method for
1
Total Molybdenum in Fresh Alumina-Base Catalysts
This standard is issued under the fixed designation D3943; 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 molybdenum in alumina-base catalysts and has been cooperatively tested at
molybdenum concentrations from 8 to 18 weight %, expressed as MoO . Any component of the catalyst other than molybdenum
3
such as iron, tungsten, etc., which is capable of being oxidized by either ferric or ceric ions after being passed through a
zinc-amalgam reductor column (Jones reductor) will interfere.
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 Many catalysts that contain molybdenum also contain other metals, nickel for example, that may be regulated by the EPA. Go
to the material safety data sheet for the catalyst material being analyzed. More information can be found at EPA.gov. Additional
information on nickel containing catalysts can be found in Test Method D4481.
1.4 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.
1.5 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
2.1 ASTM Standards:
D1193 Specification for Reagent Water
D4481 Test Method for Total Nickel in Fresh Alumina-Base Catalysts
D7442 Practice for Sample Preparation of Fluid Catalytic Cracking Catalysts and Zeolites for Elemental Analysis by Inductively
Coupled Plasma Optical Emission Spectroscopy
3
E173 Practice for Conducting Interlaboratory Studies of Methods for Chemical Analysis of Metals (Withdrawn 1998)
E507 Test Method for Determination of Aluminum in Iron Ores by Flame Atomic Absorption Spectrometry
3. Summary of Test Method
3.1 The catalyst is digested in hot sulfuric acid to dissolve molybdenum, destroy organic matter, and to expel nitrates if present.
1
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 1980. Last previous edition approved in 20102015 as
D3943D3943 – 10–10.(2015). DOI: 10.1520/D3943-10R15.10.1520/D3943-21.
2
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.
3
The last approved version of this historical standard is referenced on www.astm.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D3943 − 21
The acid solution is diluted and passed through an amalgamated zinc column (Jones reductor) into a receiving flask containing an
+6 +3
excess of ferric ammonium sulfate. The column quantitatively reduces the molybdenum (Mo to Mo ) which in turn is reoxidized
in the receiving flask according to the reaction:
13 13 16 12
Mo 13Fe →Mo 13Fe (1)
+3
3.2 The ferrous ion produced (three per Mo oxidized) is titrated with standard ceric sulfate solution in the presence of ferroin
indicator. The indicator undergoes a color change (pink to colorless or very faint blue-green) in the presence of excess ceric ion.
+2
The amount of Fe titrated in the reaction:
12 14 13 13
Fe 1Ce →Fe 1Ce (2)
+6
is a direct measure of Mo concentration.
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 cata
...