ASTM D5174-07(2013)

Standard Test Method for Trace Uranium in Water by Pulsed-Laser Phosphorimetry (Withdrawn 2022)

SIGNIFICANCE AND USE
5.1 This test method is useful for the analysis of total uranium in water following wet-ashing, as required, due to impurities or suspended materials in the water.
SCOPE
1.1 This test method covers the determination of total uranium, by concentration, in water within the calibrated range of the instrument, 0.1 μg/L or greater. Samples with uranium by mass, levels above the laser phosphorimeter dynamic range are diluted to bring the concentration to a measurable level.  
1.2 This test method was used successfully with reagent water. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.  
1.3 The values stated in SI units are to be regarded as the standard.  
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Dec-2012
• ICS: 13.060.50 - Examination of water for chemical substances
• Technical Committee: D19 - Water
• Drafting Committee: D19.04 - Methods of Radiochemical Analysis

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5174 − 07 (Reapproved 2013)
Standard Test Method for
Trace Uranium in Water by Pulsed-Laser Phosphorimetry
This standard is issued under the fixed designation D5174; 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 D5847 Practice for Writing Quality Control Specifications
for Standard Test Methods for Water Analysis
1.1 This test method covers the determination of total
D6001 Guide for Direct-Push Groundwater Sampling for
uranium, by concentration, in water within the calibrated range
Environmental Site Characterization
oftheinstrument,0.1µg/Lorgreater.Sampleswithuraniumby
E131 Terminology Relating to Molecular Spectroscopy
mass, levels above the laser phosphorimeter dynamic range are
diluted to bring the concentration to a measurable level.
3. Terminology
1.2 This test method was used successfully with reagent
3.1 Definitions:
water.Itistheuser’sresponsibilitytoensurethevalidityofthis
3.1.1 For definitions of terms used in this test method, refer
test method for waters of untested matrices.
to Terminologies D1129 and E131.
1.3 The values stated in SI units are to be regarded as the
3.1.2 For terms not defined in this test method or in
standard.
Terminology D1129 or E131, reference may be made to other
published glossaries.
1.4 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
4. Summary of Test Method
responsibility of the user of this standard to establish appro-
4.1 This test method is based on the utilization of a laser
priate safety, health, and environmental practices and deter-
phosphorimeter to determine total uranium, by mass, in water
mine the applicability of regulatory limitations prior to use.
samples.
1.5 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4.2 Asamplealiquantispipettedintoapretreatedglassvial.
ization established in the Decision on Principles for the
Concentrated HNO and hydrogen peroxide are added and the
Development of International Standards, Guides and Recom-
sample heated to dryness. This step is repeated as necessary
mendations issued by the World Trade Organization Technical
and the residue is dissolved in dilute HNO . A complexant is
Barriers to Trade (TBT) Committee.
added to an aliquant of this sample and analyzed in the
phosphorimeter.
2. Referenced Documents
4.3 For screening purposes only, an aliquant of the sample
2.1 ASTM Standards:
may be pipetted directly into the phosphorimeter cell contain-
D1129 Terminology Relating to Water
ing uranium complexant and read. This cannot be done if the
D1193 Specification for Reagent Water
sample was preserved with HCl or if the matrix is not known.
D2777 Practice for Determination of Precision and Bias of
Applicable Test Methods of Committee D19 on Water
5. Significance and Use
D3370 Practices for Sampling Water from Closed Conduits
5.1 This test method is useful for the analysis of total
D3856 Guide for Management Systems in Laboratories
uranium in water following wet-ashing, as required, due to
Engaged in Analysis of Water
impurities or suspended materials in the water.
D4448 Guide for Sampling Ground-Water MonitoringWells
6. Interferences
6.1 Absorption (Inner Filter Effect)—This effect is more
This test method is under the jurisdiction of ASTM Committee D19 on Water
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi-
severe with ultraviolet excitation light (337 nm) than with
cal Analysis.
visible excitation because many prevalent compounds have
Current edition approved Jan. 1, 2013. Published January 2013. Originally
pi-bonding and absorb strongly in this region. Ferric iron and
approved in 1991. Last previous edition approved in 2007 as D5174 – 07. DOI:
10.1520/D5174-07R13.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM See American National Standard Glossary of Terms in Nuclear Science and
Standards volume information, refer to the standard’s Document Summary page on Technology (ANSI N1.1), available from American National Standards Institute,
the ASTM website. 1430 Broadway, New York, NY 10014, www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5174 − 07 (2013)
oxy-anions such as nitrate and organic acids are examples. with deionized water before using. This is necessary to reduce
Visible excitation (425 nm) may be absorbed by yellow sample contamination from leachable uranium.
solutions, for example, chromate. The consequences of this
may be reduced signals and low analysis results. 8. Reagents
6.2 Lumiphors—Many organic substances, such as humic 8.1 Purity of Reagents—Reagent grade chemicals shall be
acidsandorganicdegradationproductsfromincompleteashing used in all tests. Unless otherwise indicated, it is intended that
emit luminescence of varying lifetimes after excitation. An all reagents shall conform to the specifications of the Commit-
advantage of kinetic phosphorescence measurement is the teeonAnalyticalReagentsoftheAmericanChemicalSociety.
ability to determine if interferences are present by observing Other grades may be used, provided it is first ascertained that
the lifetime of the decay. the reagent is of sufficiently high purity to permit its use
without lessening the accuracy of the determination. Reagent
6.3 Quenching—Shortenedtriplet-statelifetimeandreduced
blanks shall be run with all determinations.
phosphorescence intensities of the excited uranyl complex
result when quenching occurs. Reliable results cannot be 8.2 Purity of Water—Unless otherwise indicated, references
obtainedwhenquenchingexceeds80to90 %.Reducingagents towatershallbeunderstoodtomeanreagentwaterconforming
such as alcohols, halides except fluoride, and metals with to Specification D1193, Type I or better.
electronic energy levels overlapping those of uranyl ion are
8.3 Hydrogen Peroxide—Standard 30 % solution of hydro-
strong quenching agents; examples are silver, lead, iron (II),
gen peroxide (H O ); commercially available reagent grade.
2 2
manganese (II), and thallium. Results from single time-gated
8.4 Nitric Acid—(sp gr 1.42) concentrated nitric acid
instruments are particularly sensitive to even mild quenching
(HNO ).
agents such as aluminum (III), magnesium (II), calcium (II),
and strontium (II). 8.5 Nitric Acid 4 M—Add 250 mL of concentrated nitric
acid (HNO ) to 500 mL of reagent water and dilute to 1L in
6.4 Competing Reactions—For this test method to perform
reagent water, Type 1 or better.
well, the uranyl ion must be protected from various intermo-
lecular mechanisms which rapidly quench the uranyl lumines-
8.6 Nitric Acid 0.8 M—Add 50 mL of concentrated nitric
cence. Complexation fulfills this need and examples of effec- acid (HNO ) to 500 mL of reagent water and dilute to 1L in
tive agents are phosphoric acid, polyphosphates, and Uraplex.
reagent water, Type 1 or better.
6.5 Hydrochloric acid, if present, is an interference unless
NOTE1—Reagentblankshallberunonthenitricacidtoanalyzeforthe
eliminated during digestion. level of uranium.
8.7 Uranium Complexant—Phosphoric acid or Uraplex are
6.6 If the concentration of uranium in the samples exceeds
some complexants that may be used.
the calibrated range of the instrument, samples are diluted
1/100 (or otherwise as appropriate) in 0.8 M nitric acid.
9. Calibration and Standardization
6.7 When concentrations of interferences in the samples
9.1 Preparation of Standards and Sample for Laser
prevent obtaining an acceptable measurement, samples are
Measurement—Standards and samples shall be prepared in a
diluted in 0.8 M nitric acid to minimize the effects of the
similar matrix for phosphorimetric measurement. The final
interferences.
sample preparation step puts uranium into a 0.8 M HNO
7. Apparatus
matrix. Use uranium standards traceable to a National Stan-
dardizing Laboratory such as NIST or NPL.
7.1 Laser Phosphorimeter, meeting the following criteria:
7.1.1 Detection Limit—The MDL for uranium is generally
9.2 CalibrationofPhosphorimeter—Theinstructionsforthe
0.1 µg/L or less.
operation of the laser phosphorimeter are provided by the
7.1.2 Dynamic Range—The phosphorimeter must handle an
manufacturer. The phosphorimeter should be calibrated each
analytical range of 400 or greater.
day of use and the calibration verified with standards obtained
7.1.3 Instrumental Precision—The precision of repetitive
from a different stock solution than used to prepare the
measurements sufficient to obtain a relative standard deviation
calibration standards.
of less than 15 % at the low points of the calibration curves.
10. Sampling
7.2 Labware—If samples containing less than 0.1 µg/L
uranium are to be analyzed, digestion vessels (both TFE-
10.1 Collect the sample in accordance with the applicable
fluorocarbon and glassware) if used, and liquid scintillation
methods as described in Practices D3370, D4448, and Guide
vialsshouldbeleachedin4Mnitricacidandrinsedthoroughly
D6001 or other approved practices or guides.
The sole source of supply of the apparatus known to the committee at this time
is Chemchek Instruments, Inc., 1845 Terminal Drive, Suite #101, Richland, WA, Reagent Chemicals, American Chemical Society Specifications, American
99354-4959. Consult appropriate equipment manuals for explanations of calibration Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
and calculations. If you are aware of alternative suppliers, please provide this listed by the American Chemical Society, see Annual Standards for Laboratory
information to ASTM International Headquarters. Your comments will receive Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
careful consideration at a meeting of the responsible technical committee, which and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
you may attend. MD.
D5174 − 07 (2013)
11. Procedure where:
MDL = themethoddetectionlimitatthe99 %confidence
0.99
11.1 Pipet 5.0 mL of sample into a glass vial previously
level,
treated as described in 7.2.
S = standard deviation of the mean of measured
B
11.2 Add 1 mL of concentrated HNO and two or three concentration of uranium in replicate blanks in
drops of 30 % hydrogen peroxide.
concentration (µg/L),
t = student’s t value at the 99 % confidence level for
Stud
11.3 Place the vial on a hot plate and heat to dryness. Take
n-1 degrees of freedom (default = 3.143 for 6
care that spattering of the sample does not occur.
degrees of freedom),
n = numberofblanksanalyzedinthestudy(default=
NOTE 2—Placing the vial in a 50-mL beaker makes it easier to handle
and not so apt to be knocked over. 7),
x = measured concentration of uranium in blank “i,”
i
11.4 Remove the vials from the hot plate and add 1 mL of
x¯ = mean of measured concentration of uranium in
concentrated HNO , two or three drops of 30 % hydrogen
all replicate blanks in concentration (µg/L).
peroxide, and heat to dryness. Repeat as necessary until only a
12.4 Method Reporting Limit (RL):
white or translucent residue remains.
12.4.1 The method reporting limit (RL) is defined as the
11.5 Add 1.0 mL of 4 M HNO and warm gently, if
3 lowest non-zero standard on the calibration curve or the
necessary, to dissolve the residue. Then add 4.0 mL of water
calculated MDL.
conforming to Specification D1193, Type I or better . Swirl to
12.4.2 The RL shall never be established at a concentration
mix thoroughly.
below the MDL and typically is established at concentrations
3–10 times the concentration of the measured MDL.
11.6 Analyze the solution according to the instruction
manual provided with the phosphorimeter.
12.5 Reporting Results:
12.5.1 All sample results and reporting limits shall be
NOTE 3—If the concentration of uranium in the prepared sample falls
adjusted for any dilutions performed.
above the calibrated range of the instrument, dilutions should be made
12.5.2 The sample result and associated reporting limit for
using 0.8 M HNO , used for the final sample preparation.
each result equal to or greater than the RL shall be reported.
NOTE 4—Lifetime values below 200 us indicate significant quenching
in the sample and could affect the quality of results obtained.The problem 12.5.3 Sample results measured below the low point on the
can often be addressed by diluting samples in 0.8 M HNO .
3 calibration curve shall be reported as “less than the reporting
limit” (for example, < RL).
12. Calculation
13. Precision and Bias
12.1 Refer to the instrument manual for explanation of
calculations. 13.1 The collaborative test conducted on this test method
included six laboratories for Level 1 and seven laboratories for
12.2 Estimate the uncertainty of analysis by preparing and
Levels2and3.Therewereatotalofthreelevelsbetween1and
analyzing replicate analyses at different known concentrations
100 µg/L with three replicates per level. The determination of
and calculating the bias and standard deviation as a function of
the precision and bias statements were made in accordance
concentration.
with Practice D2777.
12.3 Estimate the method detection limit (MDL) and
13.2 These collaborative test data were obtained using
method reporting limit (RL) on a periodic basis or following
reagent grade water. For other matrices, these data may not
major maintenance of the instrument by processing seven or
apply.
more replicate reagent blanks through the entire above method
13.3 The bias of this test method, based upon the collab-
above. Calculate the standard deviation S and the MDL as
B
orative test data, was found to vary with level according to
described in Eq 1 and Eq 2 below.
Table 1.
NOTE5—SoftwaresuppliedwithcertainKPAinstrumentsexcludesdata
13.4 Theoverallandsingleoperatorprecisionwerefoundto
in time gates where net signal intensity falls to zero or below. Further, the
vary with level according to Table 2.
software censors final concentration results (that is, reports as “less than”
values) when there is insufficient net intensity data to perform a best-fit
regression to the decay plot.As a result, during the analysis of blanks the 14. Quality Control
instrument will often yield non-numerical concentration results (that is,
14.1 In order to be certain that analytical values obtained
“less-than” values). In such cases, “positive
...