Standard Test Method for Determination of Uranium in Mineral Acids by X-Ray Fluorescence

SIGNIFICANCE AND USE
This test method is applicable to aqueous solutions of uranium containing 0.05 to 20 g uranium per litre of solution presented to the spectrometer.
Either wavelength-dispersive or energy-dispersive X-ray fluorescence systems may be used provided the software accompanying the system is able to accommodate the use of internal standards.
SCOPE
1.1 This test method covers the steps necessary for the preparation and analysis by X-ray fluorescence (XRF) of mineral acid solutions containing uranium.
1.2 This test method is valid for those solutions containing 2 to 20 g uranium/L as presented to the spectrometer. Higher concentrations may be covered by appropriate dilutions.
1.3 This test method requires the use of an appropriate internal standard. Care must be taken to ascertain that samples analyzed by this test method do not contain the internal standard element or that this contamination has been corrected for mathematically whenever present. Such corrections are not addressed in this test method. Care must also be taken that the choice of internal standard and sample medium are compatible; that is, do not use yttrium with solutions containing HF or strontium with those having H 2 SO 4 . Alternatively a scatter line may be used as internal standard.  
1.4 The values stated in SI units are to be regarded as the standard.
1.5 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 and health practices and determine the applicability of regulatory limitations prior to use. Specific precautionary statements are given in Section 8 and Note 1.

General Information

Status
Historical
Publication Date
31-May-2005
Technical Committee
Drafting Committee
Current Stage
Ref Project

Relations

Buy Standard

Standard
ASTM C1254-99(2005) - Standard Test Method for Determination of Uranium in Mineral Acids by X-Ray Fluorescence
English language
4 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (Sample)


NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C1254 − 99 (Reapproved2005)
Standard Test Method for
Determination of Uranium in Mineral Acids by X-Ray
Fluorescence
This standard is issued under the fixed designation C1254; 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 C982 Guide for Selecting Components for Energy-
Dispersive X-Ray Fluorescence (XRF) Systems (With-
1.1 This test method covers the steps necessary for the
drawn 2008)
preparation and analysis by X-ray fluorescence (XRF) of
C1118 Guide for Selecting Components for Wavelength-
mineral acid solutions containing uranium.
Dispersive X-Ray Fluorescence (XRF) Systems (With-
1.2 This test method is valid for those solutions containing
drawn 2011)
0.05 to 20 g uranium/L as presented to the spectrometer.
D1193 Specification for Reagent Water
Higher concentrations may be covered by appropriate dilu-
E135 Terminology Relating to Analytical Chemistry for
tions.
Metals, Ores, and Related Materials
1.3 This test method requires the use of an appropriate 2.2 Other Document:
internal standard. Care must be taken to ascertain that samples
NBS Handbook 111, Radiation Safety for X-Ray Diffraction
analyzed by this test method do not contain the internal and X-Ray Fluorescence Analysis Equipment
standard element or that this contamination has been corrected
3. Terminology
for mathematically whenever present. Such corrections are not
addressed in this test method. Care must also be taken that the
3.1 Definitions:
choiceofinternalstandardandsamplemediumarecompatible;
3.1.1 See Terminology E135 for definitions of terms appli-
that is, do not use yttrium with solutions containing HF or
cable to this test method.
strontium with those having H SO .Alternatively a scatter line
2 4
may be used as internal standard. 4. Summary of Test Method
1.4 The values stated in SI units are to be regarded as the 4.1 Solution standards containing 0.025 g/L uranium to 20
standard. g/L uranium and an appropriate internal standard (usually
eitheryttriumorstrontium)areplacedinaliquidsampleholder
1.5 This standard does not purport to address all of the
of an X-ray spectrometer and exposed to an X-ray beam
safety concerns, if any, associated with its use. It is the
capable of exciting the uranium L-alpha emission line and the
responsibility of the user of this standard to establish appro-
appropriate emission line for the internal standard (usually the
priate safety and health practices and determine the applica-
K-alpha line). The intensities generated are measured by an
bility of regulatory limitations prior to use. Specific precau-
appropriate detector. The intensity ratio values obtained from
tionary statements are given in Section 8 and Note 1.
this data are used to calibrate the X-ray analyzer.
2. Referenced Documents
5. Significance and Use
2.1 ASTM Standards:
5.1 This test method is applicable to aqueous solutions of
uranium containing 0.05 to 20 g uranium per litre of solution
presented to the spectrometer.
This test method is under the jurisdiction ofASTM Committee C26 on Nuclear
5.2 Either wavelength-dispersive or energy-dispersive
Fuel Cycle and is the direct responsibility of Subcommittee C26.05 on Methods of
Test.
X-ray fluorescence systems may be used provided the software
Current edition approved June 1, 2005. Published December 2005. Originally
accompanying the system is able to accommodate the use of
approved in 1993. Last previous edition approved in 1999 as C1254 – 99. DOI:
internal standards.
10.1520/C1254-99R05.
Andermann,George,andKemp,J.W.,“ScatteredX-RaysasInternalStandards
in X-ray Spectroscopy,” Analytical Chemistry, Vol 20( 8), 1958.
3 4
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available as a photocopy from the U.S. Department of Commerce, National
the ASTM website. Institute of Standards and Technology, Gaithersburg, MD 20899.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1254 − 99 (2005)
6. Apparatus 8.2 Instrument performance may be influenced by environ-
mental factors such as heat, vibration, humidity, dust, stray
6.1 X-Ray Spectrometer—See Guide C982 or Guide C1118
electronic noise, and line voltage stability. These factors and
for the selection of the X-ray spectrometer. This test method is
performance characteristics should be reviewed prior to use of
valid for either energy-dispersive or wavelength-dispersive
this standard.
systems.
6.2 Sample Cups:
9. Preparation of Apparatus
6.2.1 Prepare liquid sample cups for the X-ray spectrometer
9.1 Chamber Environment—The standards and samples
as described by the manufacturer. Vented, disposable sample
used in this test method are corrosive liquids. Some fumes will
cups with snap-on caps are satisfactory for most such analyses;
be emitted from the sample cups. These fumes may be
such cups decrease the likelihood of contamination between
detrimental to the spectrometer chamber. It is desirable to flush
samples.
this chamber with an inert gas (usually helium) before and
6.2.2 Polyester, polyethylene, and polypropylene films have
during analysis. Some X-ray spectrometers control the change
been used successfully as the film window for such cups. Tests
of sample chamber atmosphere (air, vacuum, helium) auto-
shouldbeperformedtodeterminetheserviceabilityofanyfilm
matically through the software; in others, it must be done
chosen before insertion into the instrument.
manually. Follow the instrument manufacturer’s recommenda-
6.3 Solution Dispenser—The dispenser for the internal stan-
tions to achieve the inert gas environment.
dard solution should be capable of reproducibly dispensing the
NOTE 1—Caution: Allow sufficient stabilization time before analysis.
internal standard to a level of 0.5 % relative standard deviation
Care must be taken to ensure that a vacuum environment is not chosen
of the volume dispensed.
with liquid samples.
7. Reagents and Materials 9.2 X-Ray Power Supply—If the power to the X-ray tube is
not controlled by the instrument software, set the proper
7.1 Purity of Reagents—Reagent grade chemicals shall be
combination of voltage and current for the instrument in use.
used in all tests. Unless otherwise indicated, it is intended that
These settings must be determined by the user for his instru-
all reagents conform to the specifications of the Committee of
ment and choice of X-ray tube. Allow sufficient stabilization
Analytical Reagents of the American Chemical Society where
time prior to analysis.
such specifications are available. Other grades may be used
provided it is first ascertained that the reagent is of sufficiently
10. Calibration and Standardization
high purity to permit its use without lessening the accuracy of
the determination.
10.1 Internal Standard Solution (25.0 g/L):
10.1.1 Weigh 25 g of the chosen internal standard com-
7.2 Purity of Water—Unless otherwise indicated, references
pound into an 800-mL beaker. Cover with water. Add concen-
to water shall mean reagent water conforming to Specification
trated nitric acid slowly. For yttrium oxide the reaction will be
D1193.
slow and may require heating. For strontium carbonate, the
7.3 Ferric Nitrate, Fe(NO ) ·9H O.
3 3 2
reaction will be vigorous.
7.4 Nitric Acid, HNO , concentrated (70 %). 10.1.2 Heat on a hot plate if necessary to complete the
dissolution.
7.5 Strontium Carbonate, SrCO .
10.1.3 Cool the solution to room temperature, and transfer
7.6 Uranium Oxide, U O , NBLCRM-129 (or equivalent).
3 8
to a 1000-mL volumetric flask. (Filter the solution if neces-
7.7 Yttrium Oxide, Y O . sary.) Dilute to volume with water and mix thoroughly.
2 3
10.2 Impurity Stock Solution (Optional):
8. Technical Precautions
10.2.1 Weigh 50 g of reagent grade ferric nitrate,
8.1 XRF equipment analyzes by the interaction of ionizing
Fe(NO ) ·9H O, into a 600-mL beaker.
3 3 2
radiation with the sample. Applicable safety regulations and
10.2.2 Dissolve the crystals in 200 mL of water and 50 mL
standard operating procedures must be reviewed prior to the
of concentrated nitric acid.
use of such equipment. All modern XRF spectrometers are
10.2.3 When cool, transfer the solution to a 1000-mL
equipped with safety interlocks to prevent accidental penetra-
volumetric flask and dilute to volume with water.
tion of the X-ray beam by the user. Do NOT override these
10.3 Uranium Calibration Standards:
interlocks without proper training, or a second knowledgeable
10.3.1 Prepare a uranium standard for each concentration
person present during such operation. (See NBS Handbook
level by weighing into a 150-mL beaker the amounts of
111.)
uranium oxide given in Table 1.
10.3.2 Dissolve the oxide in 25 mL of water and 25 mL
Reagent Chemicals, American Chemical Society Specifications, American
concentrated nitric acid.
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.