ASTM C1590-21

Standard Practice for Alternate Actinide Calibration for Inductively Coupled Plasma-Mass Spectrometry

SIGNIFICANCE AND USE
5.1 One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities (that is,  232Th and 238U). Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest.  
5.2 The degree of actual mass bias is variable and is dependent upon instrument tune parameters. This standard practice uses universal interference equations to derive a mass bias correction that is specific to the instrument parameters and tune used for sample data acquisition and not based on a historical average.  
5.3 Mass bias correction uses the instrument software interference equations and does not require additional subsequent off-line calculations.  
5.4 The methodology that this standard practice is based on has been used for the determination of 232Th and  237Np in enriched uranium solutions and the determination of  241Am in plutonium and uranium legacy oxides following dissolution and ion extraction chromatography separation.  
5.5 Data presented in Section 12 were developed using a quadrupole ICP-MS. This practice can also be applied to high resolution ICP-MS with appropriate validation.
SCOPE
1.1 This practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration is mass bias adjusted using thorium-232 (232Th) and uranium-238 (238U) standards. One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities. Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest.  
1.2 The instrument response for a series of determinations of known concentration of 232Th and 238U defines the mass versus response relationship. For each standard concentration, the slope of the line defined by 232Th and  238U is used to derive linear calibration curves for each mass of interest using interference equations. The mass bias corrected calibration curves, although generated from interference equations, are specific to the instrument operating parameters and tuning in effect at the time of data acquisition. Because interference equations are part of the normal ICP-MS manufacturer's software package, this calibration methodology is widely applicable.  
1.3 For this standard practice, the actinide atomic mass range that has been studied is from AMU 232 to 244. Guidance for an extended range of AMU 228 to 248 is given in this practice.  
1.4 Using this practice, analyte concentrations are reported at each AMU and not by element total (that is, 239Pu versus plutonium).  
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
1.6 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.  
1.7 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: 71.040.50 - Physicochemical methods of analysis
• Technical Committee: C26 - Nuclear Fuel Cycle
• Drafting Committee: C26.05 - Methods of Test

Relations

• Refers: ASTM C859-24 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM C1168-23 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Oct-2023
• Refers: ASTM C1411-20 - Standard Practice for The Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis
• Effective Date: 01-Jul-2020
• Refers: ASTM C1463-19 - Standard Practices for Dissolving Glass Containing Radioactive and Mixed Waste for Chemical and Radiochemical Analysis
• Effective Date: 01-Feb-2019
• Refers: ASTM C1168-15 - Standard Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• Effective Date: 01-Sep-2015
• Refers: ASTM C859-14a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jun-2014
• Refers: ASTM C859-14 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Jan-2014
• Refers: ASTM C1411-14 - Standard Practice for The Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis
• Effective Date: 01-Jan-2014
• Refers: ASTM C1463-13 - Standard Practices for Dissolving Glass Containing Radioactive and Mixed Waste for Chemical and Radiochemical Analysis
• Effective Date: 01-Jul-2013
• Refers: ASTM C859-13a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Jun-2013
• Refers: ASTM C859-13 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-May-2013
• Refers: ASTM C859-10b - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Nov-2010
• Refers: ASTM C859-10a - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Aug-2010
• Refers: ASTM C859-10 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 01-Feb-2010
• Refers: ASTM C859-09 - Standard Terminology Relating to Nuclear Materials
• Effective Date: 15-Feb-2009

Overview

ASTM C1590-21: Standard Practice for Alternate Actinide Calibration for Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) provides a practical approach for calibrating the analysis of actinide isotopes using lower-activity standards. This methodology is especially valuable for laboratories who cannot safely handle highly radioactive calibration standards for actinide analysis. By employing thorium-232 (232Th) and uranium-238 (238U) as alternate calibration standards, this practice enhances laboratory safety while maintaining measurement integrity, making it ideal for environmental laboratories and nuclear fuel cycle applications.

Key Topics

• Alternate Calibration Approach: Enables precise quantification of selected actinide isotopes in aqueous solutions, without relying on highly radioactive standards.
• Mass Bias Correction: Utilizes calibration curves derived from 232Th and 238U standards. Universal interference equations inherent in ICP-MS software are applied to correct for instrument mass bias specific to each measurement session.
• Range and Applicability: The studied atomic mass range is AMU 232 to 244, with extended guidance for AMU 228 to 248. Analyte concentrations are reported for each atomic mass unit, not as total element content.
• Safety Considerations: Reduces the handling and storage risks associated with the use of high-activity actinide standards, supporting robust laboratory safety and compliance.
• Software Integration: Leverages standard ICP-MS software features to perform interference and mass bias corrections in real-time, removing the need for time-consuming post-processing.

Applications

ASTM C1590-21 delivers practical value for:

• Environmental Testing Laboratories: Supports accurate actinide quantitation where regulatory or facility limitations preclude high-activity standard use.
• Nuclear Safeguards and Fuel Cycle Monitoring: Applies to the analysis of uranium, plutonium, americium, and neptunium isotopes in nuclear material control and legacy waste validation.
• Radioanalytical Chemistry: Supports research, development, and routine testing in academic, governmental, and industrial laboratories that use ICP-MS for actinide determination.
• Quality Assurance/Control: Facilitates robust calibration and quantitation for quality control samples, with good precision and low bias as evidenced by validation data.
• Safety and Regulatory Compliance: Enables laboratories to fulfill method validation and traceability requirements while minimizing radiological hazards.

Related Standards

Several ASTM standards complement the application of ASTM C1590-21 by addressing preparation, separation, and terminology relevant to nuclear materials and radiochemical analysis:

• ASTM C859: Terminology Relating to Nuclear Materials
• ASTM C1168: Practice for Preparation and Dissolution of Plutonium Materials for Analysis
• ASTM C1347: Practice for Preparation and Dissolution of Uranium Materials for Analysis
• ASTM C1411: Practice for Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis
• ASTM C1463: Practices for Dissolving Glass Containing Radioactive and Mixed Waste
• ASTM D1193: Specification for Reagent Water

Summary

Adopting ASTM C1590-21 enhances laboratory capability for actinide isotope determination via ICP-MS. By using 232Th and 238U as calibration references and applying direct mass bias corrections within standard instrument software, laboratories ensure accurate, robust, and safe analysis procedures. This standard is particularly relevant in the context of environmental monitoring, nuclear fuel cycle control, and situations where handling of highly radioactive materials is restricted. Widespread applicability, integrated software corrections, and improved safety make ASTM C1590-21 an important tool for modern radiochemical analysis.

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: C1590 − 21
Standard Practice for
Alternate Actinide Calibration for Inductively Coupled
Plasma-Mass Spectrometry
This standard is issued under the fixed designation C1590; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 1.6 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
1.1 This practice provides guidance for an alternate linear
responsibility of the user of this standard to establish appro-
calibration for the determination of selected actinide isotopes
priate safety, health, and environmental practices and deter-
in appropriately prepared aqueous solutions by Inductively
mine the applicability of regulatory limitations prior to use.
Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate
232 1.7 This international standard was developed in accor-
calibrationismassbiasadjustedusingthorium-232( Th)and
238 dance with internationally recognized principles on standard-
uranium-238 ( U) standards. One of the benefits of this
ization established in the Decision on Principles for the
standard practice is the ability to calibrate for the analysis of
Development of International Standards, Guides and Recom-
highly radioactive actinides using calibration standards at
mendations issued by the World Trade Organization Technical
muchlowerspecificactivities.Environmentallaboratoriesmay
Barriers to Trade (TBT) Committee.
findthisstandardpracticeusefuliffacilitiesarenotavailableto
handle the highly radioactive standards of the individual
2. Referenced Documents
actinides of interest.
2.1 ASTM Standards:
1.2 The instrument response for a series of determinations
C859Terminology Relating to Nuclear Materials
232 238
of known concentration of Th and U defines the mass
C1168PracticeforPreparationandDissolutionofPlutonium
versus response relationship. For each standard concentration,
Materials for Analysis
232 238
theslopeofthelinedefinedby Thand Uisusedtoderive
C1347Practice for Preparation and Dissolution of Uranium
linear calibration curves for each mass of interest using
Materials for Analysis
interference equations. The mass bias corrected calibration
C1411Practice for The Ion Exchange Separation of Ura-
curves, although generated from interference equations, are
nium and Plutonium Prior to Isotopic Analysis
specific to the instrument operating parameters and tuning in
C1463Practices for Dissolving Glass Containing Radioac-
effect at the time of data acquisition. Because interference
tive and Mixed Waste for Chemical and Radiochemical
equations are part of the normal ICP-MS manufacturer’s
Analysis
software package, this calibration methodology is widely
D1193Specification for Reagent Water
applicable.
3. Terminology
1.3 For this standard practice, the actinide atomic mass
rangethathasbeenstudiedisfromAMU232to244.Guidance
3.1 Definitions:
for an extended range of AMU 228 to 248 is given in this
3.1.1 For definitions of terms relating to nuclear materials,
practice.
refer to Terminology C859.
3.2 Abbreviations:
1.4 Using this practice, analyte concentrations are reported
3.2.1 AMU—Atomic Mass Unit
at each AMU and not by element total (that is, Pu versus
plutonium).
4. Summary of Practice
1.5 The values stated in SI units are to be regarded as
4.1 Calibration for the actinides by ICP-MS can be per-
standard. No other units of measurement are included in this
formed in a variety of ways with varying degrees of data
standard.
quality. An alternative calibration method has been developed
tocompensateforinstrumentmassbiasusingageneratedmass
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJune1,2021.PublishedJuly2021.Originallyapproved contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
in 2004. Last previous edition approved in 2014 as C1590–04 (2014). DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/C1590-21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1590 − 21
232 238
response curve defined by the Th and U data points. The with dilute nitric acid to develop a calibration series covering
232 238
mass response curve defined by Th and U approximates the desired concentration range. Standard concentrations are
232 238
the mass response curve from AMU 232 to 244 as verified calculated for Th and U for each calibration solution.
experimentally and graphically depicted in Fig. 1. The mass
4.5 An internal standard is added in a fixed quantity in all
response curve shown reflects the operating parameters and
standards and samples to correct for both instrument drift and
tune of the particular instrument in use at the time of data
physical sample transport fluctuations. Typically Bi is used
collection. Different tuning parameters or instrumentation 159
but other elements, such as Tb, may also be used.
could result in varying degrees of negative, neutral, or positive
mass bias. Because the mass response curve defined by Th
5. Significance and Use
and U used in this standard practice is determined during
5.1 Oneofthebenefitsofthisstandardpracticeistheability
each calibration, all potential linear variations in mass bias are
to calibrate for the analysis of highly radioactive actinides
compensated for.
using calibration standards at much lower specific activities
232 238
4.2 The alternative calibration in this standard practice
(that is, Th and U). Environmental laboratories may find
combines the features of an external linear calibration at each
this standard practice useful if facilities are not available to
mass of interest with the mass bias correction of a mass/
handle the highly radioactive standards of the individual
response curve. The correction for mass bias is integrated into
actinides of interest.
the acquisition of the standard data through the use of
5.2 The degree of actual mass bias is variable and is
interference equations which, are part of the normal software
dependent upon instrument tune parameters. This standard
package for correction of isobaric interference’s in ICP-MS
practice uses universal interference equations to derive a mass
analyses. Multipoint calibration curves are generated at each
biascorrectionthatisspecifictotheinstrumentparametersand
mass of interest, resulting in more accurate quantification than
tune used for sample data acquisition and not based on a
that of the typical “semi-quantitative” single point calibration
historical average.
based on the mass/response curve alone.
5.3 Mass bias correction uses the instrument software inter-
4.3 Sample analyses for blanks and samples are performed
ference equations and does not require additional subsequent
using a data acquisition method file without the interference
off-line calculations.
equations that were used to derive the calibration curves.After
5.4 The methodology that this standard practice is based on
calibrationcurvesaregenerated,thecalibrationfilesarecopied
232 237
has been used for the determination of Th and Np in
or linked to the analytical acquisition method. The sample
enriched uranium solutions and the determination of Am in
responses are acquired at each mass, and concentrations
plutonium and uranium legacy oxides following dissolution
calculated from the mass bias corrected calibration curves.
and ion extraction chromatography separation.
SomeICP-MSvendorsuppliedcontrolsoftwarewillpermitthe
linkingofseparatecalibrationandacquisitionfiles(thatis,one
5.5 Data presented in Section 12 were developed using a
can choose which calibration files to use to quantitate any
quadrupole ICP-MS. This practice can also be applied to high
particular data set regardless of the acquisition file that was
resolution ICP-MS with appropriate validation.
used to acquire the data).
6. Interferences
4.4 Mixed calibration standard solutions are prepared
through dilution of single element stock standards of thorium 6.1 Isotopes of different elements forming atomic ions with
and known abundance uranium (normally depleted in U) the same nominal mass-to-charge ratio (m/z) may cause
isobaric interferences in ICP-MS if present in sufficient quan-
238 238 241 241
tity (that is, U with Pu and Pu with Am). Because
the isotopic abundance of actinides vary widely, it is not
practical to apply an interference correction unless the isotopic
abundanceoftheinterferenceiswellcharacterized.Inaddition,
the hydride of an abundant isotope can interfere with the
238 1 239
adjacent higher mass (that is, UHon Pu). For these
reasons,itisprudenttoimplementactinideseparationmethods
utilizing extraction chromatography resins prior to ICP-MS
analysis to significantly reduce these interferences.
6.2 Analyte memory can occur when there are large con-
centration differences between standards and/or samples that
are analyzed sequentially.Thorium can exhibit memory within
the sample introduction system. A rinse solution containing
0.2M nitric acid and 0.2M sulfuric acid has been found to be
beneficial in reducing thorium carryover.
Maxwell, S. L, “Rapid Actinide-Separation Methods,” Journal of Applied
FIG. 1 Atomic Mass Versus Average Normalized Response Radioactivity Measurements, Vol 8, No. 4, 1997, pp. 36-44.
C1590 − 21
7. Apparatus 9. Hazards
7.1 ICP-MS, computer controlled with associated software
9.1 Personnel using this procedure shall be knowledgeable
and peripherals.
of the safety precautions necessary for normal chemical,
radiological handling protocol and instrumental operation of
7.2 Autosampler, optional, with tube racks, disposable plas-
ICP-MS.
tic sample tubes.
7.3 Variable Micro and Macro Pipettes .
9.2 Nitric and sulfuric acids are strong oxidizers, avoid
contact with flammable, powdered, or combustible materials.
8. Reagents
Avoid contact with skin, eyes and clothing. Do not breathe or
8.1 Argon (Ar) Gas, high purity ≥ 99.99%.
ingest vapors.
8.2 Deionized Water, high purity, conforming to Specifica-
9.3 Actinide bearing materials are radioactive and toxic.
tion D1193, Type I.
Adequatelaboratoryfacilitiesandventilationhoodsalongwith
8.3 Nitric Acid, (Specific Gravity 1.42), concentrated nitric safehandlingtechniquesmustbeused.Adetaileddiscussionof
acid (HNO ), trace metal grade or better.
all safety precautions needed is beyond the scope of this
standard practice. Follow site and facility specific radiation
8.4 Sulfuric Acid, (Specific Gravity 1.84), concentrated sul-
protection and chemical hygiene protocol.
furic acid (H SO ), trace metal grade or better.
2 4
8.5 Bismuth Stock Solution, (1000 µg/mL Bi), matrix nomi-
10. Procedure
nal 10% HNO .
10.1 Calibration Standard Preparation—Because the focus
8.6 Thorium Stock Solution, (1000 µg/mL Th),matrixnomi-
of this practice is on mass bias correction and not on any
nal 2% HNO .
particular calibration concentration range or sample matrix,
8.7 Uranium Stock Solution, (1000 µg/mL U), matrix nomi-
minimal instruction is given for the preparation of calibration
nal 2% HNO .
standards.
241 242 244
8.8 Radioisotope Standards ( Am, Pu, Cm, etc.) can
10.1.1 Mixed Calibration Standard solutions are prepared
be purchased to verify calibration curves if laboratory and
through the quantitative dilution of single element bench stock
ICP-MS have proper engineering and procedural controls to
standardsofthoriumandknownabundanceuranium(normally
235 209
safely handle radiological material.
depleted in U) with an internal standard (such as Bi or
Tb) in nominal 1% nitric acid or other acid concentration
appropriate to match sample matrix. A final concentration of
Eckert and Ziegler Isotope Products, 24937 Avenue Tibbitts, Valencia, CA
10µg⁄mL for each element is recommended.
91355, www.ezag.com.
TABLE 1 Universal Interference Equations Used to Perform Calibration Mass Bias Correction
Mass Bias Corrected Calibration Response Calibration Interference Equation
Corrected (228) = Response (228) ×0−(238) × 0.6667 + (232) × 1.6667
Corrected (229) = Response (229) ×0−(238) × 0.5 + (232) × 1.5
Corrected (230) = Response (230) ×0−(238) × 0.3333 + (232) × 1.3333
Corrected (231) = Response (231) ×0−(238) × 0.1667 + (232) × 1.1667
Corrected (232) = Response (232) × 1
Corrected (233) = Response (233) ×0+(238) × 0.1667 + (232) × 0.8333
Corrected (234) = Response (234) ×0+(238) × 0.3333 + (232) × 0.6667
Corrected (235) = Response (235) ×0+(238) × 0.5 + (232) × 0.5
Corrected (236) = Response (236) ×0+(238) × 0.6667 + (232) × 0.3333
Corrected (237) = Response (237) ×0+(238) × 0.8333 + (232) × 0.1667
Corrected (238) = Response (238) × 1
Corrected (239) = Response (239) ×0+(238) × 1.1667 − (232) × 0.1667
Corrected (240) = Response (240) ×0+(238) × 1.3333 − (232) × 0.3333
Corrected (241) = Response (241) ×0+(238) × 1.5 − (232) × 0.5
Corrected (242) = Response (242) ×0+(238) × 1.6667 − (232) × 0.6667
Corrected (243) = Response (243) ×0+(238) × 1.8333 − (232) × 0.8333
Corrected (244) = Response (244) ×0+(238) ×2−(232) × 1
Corrected (245) = Response (245) ×0+(238) × 2.1667 − (232) × 1.1667
Corrected (246) = Response (246) ×0+(238) × 2.3333 − (232) × 1.3333
...

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: C1590 − 04 (Reapproved 2014) C1590 − 21
Standard Practice for
Alternate Actinide Calibration for Inductively Coupled
Plasma-Mass Spectrometry
This standard is issued under the fixed designation C1590; 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 practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in
appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration
232 238
is mass bias adjusted using thorium-232 ( Th) and uranium-238 ( U) standards. One of the benefits of this standard practice
is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities.
Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive
standards of the individual actinides of interest.
232 238
1.2 The instrument response for a series of determinations of known concentration of Th and U defines the mass versus
232 238
response relationship. For each standard concentration, the slope of the line defined by Th and U is used to derive linear
calibration curves for each mass of interest using interference equations. The mass bias corrected calibration curves, although
generated from interference equations, are specific to the instrument operating parameters and tuning in effect at the time of data
acquisition. Because interference equations are part of the normal ICP-MS manufacturer’s software package, this calibration
methodology is widely applicable.
1.3 For this standard practice, the actinide atomic mass range that has been studied is from amu 232–244. AMU 232 to 244.
Guidance for an extended range of amu 228–248 AMU 228 to 248 is given in this practice.
1.4 Using this practice, analyte concentrations are reported at each amuAMU and not by element total (that is, Pu versus
plutonium).
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 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.
1.7 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.
This practice is under the jurisdiction of ASTM Committee C26 on Nuclear Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of Test.
Current edition approved Jan. 1, 2014June 1, 2021. Published February 2014July 2021. Originally approved in 2004. Last previous edition approved in 20092014 as
C1590 – 04 (2009).(2014). DOI: 10.1520/C1590-04R14.10.1520/C1590-21.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1590 − 21
2. Referenced Documents
2.1 ASTM Standards:
C859 Terminology Relating to Nuclear Materials
C1168 Practice for Preparation and Dissolution of Plutonium Materials for Analysis
C1347 Practice for Preparation and Dissolution of Uranium Materials for Analysis
C1411 Practice for The Ion Exchange Separation of Uranium and Plutonium Prior to Isotopic Analysis
C1414 Practice for The Separation of Americium from Plutonium by Ion Exchange (Withdrawn 2020)
C1463 Practices for Dissolving Glass Containing Radioactive and Mixed Waste for Chemical and Radiochemical Analysis
D1193 Specification for Reagent Water
3. Terminology
3.1 Definitions:
3.1.1 For definitions of terms relating to nuclear materials, refer to Terminology C859.
3.1.2 AMU—atomic mass unit.
3.2 Abbreviations:
3.2.1 AMU—Atomic Mass Unit
4. Summary of Practice
4.1 Calibration for the actinides by ICP-MS can be performed in a variety of ways with varying degrees of data quality. An
alternative calibration method has been developed to compensate for instrument mass bias using a generated mass response curve
232 238 232 238
defined by the Th and U data points. The mass response curve defined by Th and U approximates the mass response
curve from amu 232–244 AMU 232 to 244 as verified experimentally and graphically depicted in Fig. 1. The mass response curve
shown reflects the operating parameters and tune of the particular instrument in use at the time of data collection. Different tuning
parameters or instrumentation could result in varying degrees of negative, neutral, or positive mass bias. Because the mass response
232 238
curve defined by Th and U used in this standard practice is determined during each calibration, all potential linear variations
in mass bias are compensated for.
4.2 The alternative calibration in this standard practice combines the features of an external linear calibration at each mass of
interest with the mass bias correction of a mass/response curve. The correction for mass bias is integrated into the acquisition of
the standard data through the use of interference equations which, are part of the normal software package for correction of isobaric
FIG. 1 Atomic Mass versusVersus Average Normalized Response
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.
C1590 − 21
interference’s in ICP-MS analyses. Multipoint calibration curves are generated at each mass of interest, resulting in more accurate
quantification than that of the typical “semi-quantitative” single point calibration based on the mass/response curve alone.
4.3 Sample analyses for blanks and samples are performed using a data acquisition method file without the interference equations
that were used to derive the calibration curves. After calibration curves are generated, the calibration files are copied or linked to
the analytical acquisition method. The sample responses are acquired at each mass, and concentrations calculated from the mass
bias corrected calibration curves. Some ICP-MS vendor supplied control software will permit the linking of separate calibration
and acquisition files (that is, youone can choose which calibration files to use to quantitate any particular data set regardless of the
acquisition file that was used to acquire the data).
4.4 Mixed calibration standard solutions are prepared through dilution of single element stock standards of thorium and known
abundance uranium (normally depleted in U) with dilute nitric acid to develop a calibration series covering the desired
232 238
concentration range. Standard concentrations are calculated for Th and U for each calibration solution.
4.5 Bismuth-209 (An Bi) is used as an internal standard and is added in a fixed quantity in all standards and samples to correct
209 159
for both instrument drift and physical sample transport fluctuations. Typically Bi is used but other elements, such as Tb, may
also be used.
5. Significance and Use
5.1 One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using
232 238
calibration standards at much lower specific activities (that is, Th and U). Environmental laboratories may find this standard
practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest.
5.2 The degree of actual mass bias is variable and is dependent upon instrument tune parameters. This standard practice uses
universal interference equations to derive a mass bias correction that is specific to the instrument parameters and tune used for
sample data acquisition and not based on a historical average.
5.3 Mass bias correction uses the instrument software interference equations and does not require additional subsequent off-line
calculations.
232 237
5.4 The methodology that this standard practice is based on has been used for the determination of Th and Np in enriched
uranium solutions and the determination of Am in plutonium and uranium legacy oxides following dissolution and ion
extraction chromatography separation.
5.5 Data presented in Section 12 were developed using a quadrupole ICP-MS. This practice can also be applied to high resolution
ICP-MS with appropriate validation.
6. Interferences
6.1 Isotopes of different elements forming atomic ions with the same nominal mass-to-charge ratio (m/z) may cause isobaric
238 238 241 241
interferences in ICP-MS if present in sufficient quantity (that is, U with Pu and Pu with Am). Because the isotopic
abundance of actinides vary widely, it is not practical to apply an interference correction unless the isotopic abundance of the
interference is well characterized. In addition, the hydride of an abundant isotope can interfere with the adjacent higher mass (that
238 1 239
is, U H on Pu). For these reasons, it is prudent to implement actinide separation methods utilizing extraction chromatography
resins prior to ICP-MS analysis to significantly reduce these interferences.
6.2 Analyte memory can occur when there are large concentration differences between standards and/or samples that are analyzed
sequentially. Thorium can exhibit memory within the sample introduction system. A rinse solution containing 0.2M Nitric0.2 M
nitric acid and 0.2M Sulfuric0.2 M sulfuric acid has been found to be beneficial in reducing thorium carryover.
7. Apparatus
7.1 ICP-MS, computer controlled with associated software and peripherals.
Maxwell, S. L, “Rapid Actinide-Separation Methods,” Journal of Applied Radioactivity Measurements, Vol 8, No. 4, 1997, pp. 36-44.
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7.2 Autosampler, optional, with tube racks, disposable plastic sample tubes.
7.3 Variable Micro and Macro Pipettes .
8. Reagents
8.1 Argon (Ar) Gas, high purity ≥ 99.99 %.
D1193, Type I.
8.2 Deionized Water, high purity, conforming to Specification
8.3 Nitric Acid, (specific gravity(Specific Gravity 1.42), concentrated nitric acid (HNO ), trace metal grade or better.
8.4 Sulfuric Acid, (specific gravity(Specific Gravity 1.84), concentrated sulfuric acid (H SO ), trace metal grade or better.
2 4
8.5 Bismuth Stock Solution, (1000 μg/mL Bi), matrix nominal 10 % HNO .
8.6 Thorium Stock Solution, (1000 μg/mL Th), matrix nominal 2 % HNO .
8.7 Uranium Stock Solution, (1000 μg/mL U), matrix nominal 2 % HNO .
241 242 244 4
8.8 Radioisotope Standards ( Am, Pu, Cm, etc.) can be purchased to verify calibration curves if laboratory and ICP-MS
have proper engineering and procedural controls to safely handle radiological material.
9. Hazards
9.1 Personnel using this procedure shall be knowledgeable of the safety precautions necessary for normal chemical, radiological
handling protocol and instrumental operation of ICP-MS.
9.2 Nitric and sulfuric acids are strong oxidizers, avoid contact with flammable, powdered, or combustible materials. Avoid
contact with skin, eyes and clothing. Do not breathe or ingest vapors.
TABLE 1 Universal Interference Equations Used to Perform Calibration Mass Bias Correction
Mass Bias Corrected Calibration Response Calibration Interference Equation
Corrected (228) = Response (228) × 0 − (238) × 0.6667 + (232) × 1.6667
Corrected (229) = Response (229) × 0 − (238) × 0.5 + (232) × 1.5
Corrected (230) = Response (230) × 0 − (238) × 0.3333 + (232) × 1.3333
Corrected (231) = Response (231) × 0 − (238) × 0.1667 + (232) × 1.1667
Corrected (232) = Response (232) × 1
Corrected (233) = Response (233) × 0 + (238) × 0.1667 + (232) × 0.8333
Corrected (234) = Response (234) × 0 + (238) × 0.3333 + (232) × 0.6667
Corrected (235) = Response (235) × 0 + (238) × 0.5 + (232) × 0.5
Corrected (236) = Response (236) × 0 + (238) × 0.6667 + (232) × 0.3333
Corrected (237) = Response (237) × 0 + (238) × 0.8333 + (232) × 0.1667
Corrected (238) = Response (238) × 1
Corrected (239) = Response (239) × 0 + (238) × 1.1667 − (232) × 0.1667
Corrected (240) = Response (240) × 0 + (238) × 1.3333 − (232) × 0.3333
Corrected (241) = Response (241) × 0 + (238) × 1.5 − (232) × 0.5
Corrected (242) = Response (242) × 0 + (238) × 1.6667 − (232) × 0.6667
Corrected (243) = Response (243) × 0 + (238) × 1.8333 − (232) × 0.8333
Corrected (244) = Response (244) × 0 + (238) × 2 − (232) × 1
Corrected (245) = Response (245) × 0 + (238) × 2.1667 − (232) × 1.1667
Corrected (246) = Response (246) × 0 + (238) × 2.3333 − (232) × 1.3333
Corrected (247) = Response (247) × 0 + (238) × 2.5 −(232) × 1.5
Corrected (248) = Response (248) × 0 + (238) × 2.6667 − (232) × 1.6667
Isotope Products Laboratories, 3017 N. San Fernando Blvd., Burbank, CA 91504; [phone].Eckert and Ziegler Isotope Products, 24937 Avenue Tibbitts, Valencia,
CA 91355, www.ezag.com.
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9.3 Actinide bearing materials are radioactive and toxic. Adequate laboratory facilities and ventilation hoods along with safe
handling techniques must be used. A detailed discussion of all safety precautions needed is beyond the scope of this standard
practice. Follow site and facility specific radiation protection and chemical hygiene protocol.
10. Procedure
10.1 Calibration Standard Preparation—Because the focus of this practice is on mass bias correction and not on any particular
calibration concentration range or sample matrix, minimal instruction is given for the preparation of calibration standards.
10.1.1 Mixed Calibration Standard solutions are prepared through the quantitative dilution of single element bench stock
standards of thorium and known abundance uranium (normally depleted in U) with bismuth as an internal standard (such as
209 159
Bi or Tb) in nominal 1 % nitric acid or other acid concentration appropriate to match sample matrix. A final concentration
of 10 μg ⁄mL for each element is recommended.
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10.1.2 Calibration Blank consists of the same acid matrix as the standard solutions with the same concentration bismuthof internal
standard.
10.1.3 Reagent Blank consists of the same acid and chemical matrix as the samples (if different from t
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