ASTM D7535-09(2015)
(Test Method)Standard Test Method for Lead-210 in Water (Withdrawn 2024)
Standard Test Method for Lead-210 in Water (Withdrawn 2024)
SIGNIFICANCE AND USE
5.1 This test method was developed to measure the concentration of 210Pb in nonprocess water samples. This test method may be used to determine the concentration of 210Pb in environmental samples.
SCOPE
1.1 This test method covers the determination of radioactive 210Pb in environmental water samples (for example, drinking, non-process and effluent waters) in the range of 37 mBq/L (1.0 pCi/L) or greater.
1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information purposes only.
1.3 This method has been used successfully with tap water. It is the user's responsibility to ensure the validity of this test method for samples larger than 500 mL and for waters of untested matrices.
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. For specific hazards statements, see Section 9.
WITHDRAWN RATIONALE
This test method covers the determination of radioactive 210Pb in environmental water samples (for example, drinking, non-process and effluent waters) in the range of 37 mBq/L (1.0 pCi/L) or greater.
Formerly under the jurisdiction of Committee D19 on Water, this test method was withdrawn in January 2024 in accordance with section 10.6.3 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.
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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: D7535 − 09 (Reapproved 2015)
Standard Test Method for
Lead-210 in Water
This standard is issued under the fixed designation D7535; 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 E691Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers the determination of radioac-
tive Pb in environmental water samples (for example,
3. Terminology
drinking, non-process and effluent waters) in the range of 37
3.1 Definitions—For definitions of terms used in this test
mBq/L (1.0 pCi/L) or greater.
method, refer to Terminology D1129.
1.2 The values stated in SI units are to be regarded as
4. Summary of Test Method
standard. The values given in parentheses are provided for
information purposes only.
4.1 This test method is based on the utilization of solid
phase extraction of lead from water samples with detection of
1.3 This method has been used successfully with tap water.
It is the user’s responsibility to ensure the validity of this test theradioactiveleadbybetagasflowproportionalcounting.An
aliquotofthesampleismeasuredintoabeaker;ironcarrierand
method for samples larger than 500 mL and for waters of
untested matrices. lead carrier are added. Lead is scavenged by an iron hydroxide
precipitation. Lead is then selectively sorbed on a solid phase
1.4 This standard does not purport to address all of the
extraction column and eluted with water. Lead is precipitated
safety concerns, if any, associated with its use. It is the
asleadsulfateandiscollectedonafilterpaper.Theleadsulfate
responsibility of the user of this standard to establish appro-
precipitate is covered with aluminum foil and held for 5 days
priate safety and health practices and determine the applica-
or longer for Bi ingrowth. It is then counted for beta
bilityofregulatorylimitationspriortouse.Forspecifichazards
radiation on a gas flow proportional counter.
statements, see Section 9.
5. Significance and Use
2. Referenced Documents
5.1 This test method was developed to measure the concen-
2.1 ASTM Standards:
tration of Pb in nonprocess water samples.This test method
D1129Terminology Relating to Water
may be used to determine the concentration of Pb in
D1193Specification for Reagent Water
environmental samples.
D2777Practice for Determination of Precision and Bias of
Applicable Test Methods of Committee D19 on Water
6. Interferences
D3370Practices for Sampling Water from Closed Conduits
6.1 Significant amounts of stable lead (>0.3 mg/L) present
D4448GuideforSamplingGround-WaterMonitoringWells
in the sample will interfere with the chemical yield
D5847Practice for Writing Quality Control Specifications
determination, leading to positive bias in the yield. If it is
for Standard Test Methods for Water Analysis
known or suspected that natural lead is present in the sample,
D6001Guide for Direct-Push Groundwater Sampling for
blanksamplealiquotstowhichnoleadcarriercontentisadded
Environmental Site Characterization
should be analyzed. The amount of natural lead contained in
D7282Practice for Set-up, Calibration, and Quality Control
the sample shall be used to correct the yield.
of Instruments Used for Radioactivity Measurements
6.2 In most cases measurable amounts of Pb will be
present in the Pb carrier used in 12.1. This additional contri-
This test method is under the jurisdiction ofASTM Committee D19 on Water
butiontothemeasuredsampleactivitymustbedeterminedand
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi-
treated as additional background activity. For each new carrier
cal Analysis.
solution, the inherent Pb in the carrier must be measured.A
Current edition approved Jan. 1, 2015. Published January 2015. Originally
ε1
brief description of this additional background calibration is
approved in 2009. Last previous edition approved in 2009 as D7535 – 09 . DOI:
10.1520/D7535-09R15.
given in 11.2. Accurate determination of the combined stan-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dard uncertainty and the minimum detectable concentration
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
should include this additional activity in the method back-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ground count rate.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7535 − 09 (2015)
6.3 Previous experimental data suggests that barium con- and applied as a correction when calculating the test sample
centrations of approximately 30 ppm can be a source of result.Thisincreasedbackgroundreducesthesensitivityofthe
interference,leadingtochemicalyielddeterminationsthatmay measurement.
be non-representative and outside normal acceptance criteria.
8.2 Purity of Water—Unless otherwise indicated, reference
towatershallbeunderstoodtomeanreagentwaterconforming
7. Apparatus
to Specification D1193, Type III.
7.1 Analytical Balance, 0.0001 g.
8.3 Ammonium hydroxide—15MNH OH, (concentrated
NOTE 1—A thickness of aluminum of approximately 0.003 in. (areal
reagent).
density of approximately 0.02 mg/cm ) is needed to effectively eliminate
210 3
8.4 Iron Carrier (20 mg/mL)—Dissolve 9.6 g of ferric
the 60 keV beta particles from Pb. The thickness of aluminum foil
used during calibration of the detector and measurement samples must be
chloride (FeCl ·6H O) in 70 mL of 0.5 M HCl and dilute to
3 2
210 210
held constant to maintain self-absorption of Pb and Bi beta particles
100 mL with 0.5 M HCl.
at a constant level.
8.5 Nitric Acid, 16 M HNO —(concentrated reagent) (sp gr
7.2 Aluminum foil.
1.42).
7.3 Centrifuge.
8.5.1 Nitric Acid,8MHNO —Add 500 mLof concentrated
nitric acid to 400 mL water. Dilute to 1 L with water and mix
7.4 Centrifuge tubes (50 mL plastic).
well.
7.5 Filters, 25 mm polypropylene,0.1µm,withpolycarbon-
8.5.2 Nitric Acid,1MHNO —Add 63 mL of concentrated
ate base and metal screen.
nitric acid to 800 mL water. Dilute to 1 L with water and mix
7.6 Filter apparatus, polysulfone funnel and 100 mL poly-
well.
propylene flask.
8.5.3 Nitric Acid, 0.1 M HNO —Add 6.4 mL of concen-
tratednitricacidto600mLwater.Diluteto1Lwithwaterand
7.7 Beta Gas Flow Proportional Counting System, (<1.0
mix well.
cpm beta), low background.
8.6 Lead Carrier (10 grams Pb/L)—Dissolve 1.60 g of lead
7.8 Glass stir rods.
nitrate in water and dilute to 100 mL with water.
7.9 Glass beakers.
8.7 Lead Extraction Chromatography Column, 2-mL bed
7.10 Hot plate.
volume, 100–150 µm particle size.
7.11 Petri dish.
8.8 Pb-210 Standardizing Solution—Traceable to a national
7.12 Planchets, stainless steel, flat, with diameter large
standardizinglaboratorysuchasNationalInstituteofStandards
enough to hold the 25 mm filter.
and Technology, Gaithersburg, MD, USA (NIST) or National
Physical Laboratory, Teddington, Middlesex, UK, (NPL) with
7.13 Tweezers.
less than 0.1 mg of stable lead per mL of final solution with a
7.14 Watch glass. 210
typical Pb concentration range from 85 to 125 Bq/mL.
The Pb calibration source should be in equilibrium with its
8. Reagents and Materials
progeny Bi.
8.1 Purity of Reagents—Reagent grade chemicals shall be
8.9 Sulfuric Acid, 18 M H SO —concentratedreagent(spgr
2 4
used in all tests. Unless otherwise indicated, it is intended that
1.84).
all reagents shall conform to the specifications of the Commit-
tee onAnalytical Reagents of theAmerican Chemical Society,
9. Hazards
where such specifications are available. Other grades may be
9.1 Use extreme caution when handling all acids. They are
used, provided that the reagent is of sufficiently high purity to
extremely corrosive, and skin contact could result in severe
permit its use without increasing the background of the
burns.
measurement. Some reagents, even those of high purity, may
9.2 When diluting concentrated acids, always use safety
contain naturally occurring radioactivity, such as isotopes of
glasses and protective clothing, and add the acid to the water.
uranium, radium, actinium, thorium, rare earths and potassium
compounds and/or artificially produced radionuclides.
10. Sampling
Consequently, when such reagents are used in the analysis of
10.1 CollectasampleinaccordancewithGuidesD4448and
low-radioactivity samples, the activity of the reagents shall be
D6001 and Practice D3370, or other documented procedure as
determined under analytical conditions that are identical to
appropriate.
those used for the sample. The activity contributed by the
reagents may be considered to be a component of background
Resin available in bulk form and in prepacked columns or cartridges from
Eichrom Technologies LLC, Lisle, IL 60532. If you are aware of alternative
Radiological Health Handbook, Revised Editions January 1970, Compiled and suppliers, please provide this information to ASTM International Headquarters.
Edited by the Bureau of Radiological Health and the Training Institute Environ- Your comments will receive careful consideration at a meeting of the responsible
mental Control Administration, US Department of Health, Education and Welfare. technical committee, which you may attend.
D7535 − 09 (2015)
2 2 2 2
11. Calibration u R 1u R R 2 R u m
~ ! ~ ! ~ !
a b a b s
2 2 ˆ 2
u ~ε ! 5 1 3 1u ~F ! 3DF
S S D D
c Bi 2 2 2 c c
m 3IF m 3IF m
s s s
11.1 Detection Effıciency Calibration (see also Practice
2 2 2 2 2 2
c 3V u c u V u c u V
~ ! ~ ! ~ ! ~ !
c c s s c c
D7282):
3 1ε 3 1 1 1
S D
2 2 2 Bi 2 2 2 2
c 3V 3DF c V c V
s s s s c c
11.1.1 Prepare a set of three working calibration sources
(2)
according to the calibration procedure outlined in the subse-
where u(·) denotes standard uncertainty; for example, u(V )
s
quent steps.
is the standard uncertainty of V .
s
11.1.2 Pipet 1.0 mL of lead carrier into a small beaker.
11.1.8.1 Eq 2 omits the uncertainties due to the activity
11.1.3 Add 1.0 mL of Pb standardizing solution to the
concentration of the calibration standard solution, c , and the
s
beaker and evaporate to near dryness on a hot plate at a low
concentration of the carrier solution, c . These uncertainty
c
setting. components are accounted for when the average efficiency is
determined (below).
11.1.4 Redissolve the residue in 10 mL of1MHNO .
11.1.8.2 The procedure requires an average of (at least)
11.1.5 Follow the steps described in 12.9 through 12.28.
three efficiencies (N = 3) measured using three calibration
11.1.6 Count to amass at least 10 000 counts. Record the
sources on each detector. For this purpose, calculate ε , ε , ε
1 2 3
time and date of the midpoint of this counting period as t .
m
for each source, and use Eq 3 to calculate the weighted
11.1.7 Detection Effıciency Calculation—Calculate the de-
average:
tectionefficiencyfor Biforeachcalibrationsourceandeach
N
detector using Eq 1. εH 5 ε (3)
Bi ( i
N
i51
R 2 R
a b
11.1.8.3 To calculate the uncertainty of the average, includ-
ε 5 (1)
Bi
c 3V 3DF 3IF 3Y
s s Pb
ing uncertainty components due to systematic errors, Eq 4 is
where: used:
ε = detection efficiency for Bi,
Bi N 2 2
1 u c u c
–1 ~ ! ~ !
s c
2 2
R = total count rate (s ) for calibration source, (counts
a u εH 5Œ u ε 1εH 3 1 (4)
~ ! ~ ! S D
Bi 2 ( c i Bi 2 2
N c c
i51
s c
divided by count time (s))
–1 210
R = count rate (s ) for blank or background source, 11.2 Determination of Inherent Pb in Pb Carrier:
b
(counts divided by count time (s)) 11.2.1 Asnotedin6.2,incaseswherethePbcarrierusedin
210 210
IF = correction factor for ingrowth of Bi from Pb
this procedure has not been determined to be free of Pb,
between the time of the bismuth separation to the
the Pb content inherent in the lead carrier used in this
2λ ~t 2t !
Bi m s
midpoint of counting, 12e , where:
method must be evaluated. Each new carrier solution must be
210 210
210 –6 –1
measured for Pb prior to use. Once the Pb content of the
λ = decay constant for Bi, (1.60 × 10 s ),
Bi
210 210
t = date and time of Bi separation, and
lead carrier is known, the Pb count rate from the recovered
s
t =midpointofcountofcalibrationmount(dateand
m lead carrier can be calculated for each sample analyzed. The
time).
following step provides a protocol to determine the inherent
DF = correction factor for decay of Pb in the carrier
210Pb in the lead carrier and Section 13 provides the equations
solutionfromthecarrieractivityreferencedatetothe 210
needed to correct for the Pb inherent in the lead carrier.The
2λ ~t 2t !
Pb s r
time of the bismuth separation,e , where:
specific number of samples, as well as acceptance criteria for
210 −10 −1
λ = decay constant for Pb, (9.85 × 10 s ),
Pb the data and statistical tests to determine detectable Pb in
t = reference date and time of Pb calibration of
r
the lead carrier, should be specified in the laboratory’s Quality
lead carrier, and
Systems Manual.
t = date and time of Bi separation.
s
11.2.2 To a minimum of five 50 mLcentrifuge tubes, add 1
c = activity concentration (or massic activity) of the
s
mL of the Pb carrier solution.
calibration standard solution (Bq/unit),
11.2.3 Add 20 mL of water and 4 mL concentrated sulfuric
V = volume(ormass)ofstandardsolutionused(mLorg),
s
acid to each centrifuge tube.
Y = chemical yield of lead (see 13.1 and 13.2); Y
Pb Pb
11.2.4 Continue with the normal sample preparation, begin-
5m / c 3V , where:
~ !
s c c
ning at 12.16.
m = net mass (mg) of lead sulfate found in the
s
11.2.5 After counting, calculate for each sample the Pb
source, equal to m −m , where m is the total
F+P F F+P
mass of the filter plus precipitate and m is the tare
concentration and associated uncertainty according to Section
F
mass (filter only),
13.Calculatetheweightedaverage aˆ andstandarduncertainty
c
c = mass concentration (mg/mL) of lead (as sulfate) 210
c
u(aˆ ) of the Pb concentration using the calculated sample
c
in the carrier solution (see Eq 5), and
results from the data set using the equations in 13.3.
V = volume of carrier solution added (mL).
c
Eq1assumesthatany PbactivitycontaminationinthePb
12. Procedure
carrierisinsignificantcomparedtotheamountof Pbactivity NOTE 2—See Fig. 1 for a diagram of the procedure.
in the calibration source spike.
12.1 Add 1.0 mL of lead carrier and 1.0 mL of iron carrie
...
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: D7535 − 09 (Reapproved 2015)
Standard Test Method for
Lead-210 in Water
This standard is issued under the fixed designation D7535; 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 E691 Practice for Conducting an Interlaboratory Study to
Determine the Precision of a Test Method
1.1 This test method covers the determination of radioac-
tive Pb in environmental water samples (for example,
3. Terminology
drinking, non-process and effluent waters) in the range of 37
3.1 Definitions—For definitions of terms used in this test
mBq/L (1.0 pCi/L) or greater.
method, refer to Terminology D1129.
1.2 The values stated in SI units are to be regarded as
standard. The values given in parentheses are provided for 4. Summary of Test Method
information purposes only.
4.1 This test method is based on the utilization of solid
1.3 This method has been used successfully with tap water. phase extraction of lead from water samples with detection of
the radioactive lead by beta gas flow proportional counting. An
It is the user’s responsibility to ensure the validity of this test
method for samples larger than 500 mL and for waters of aliquot of the sample is measured into a beaker; iron carrier and
lead carrier are added. Lead is scavenged by an iron hydroxide
untested matrices.
precipitation. Lead is then selectively sorbed on a solid phase
1.4 This standard does not purport to address all of the
extraction column and eluted with water. Lead is precipitated
safety concerns, if any, associated with its use. It is the
as lead sulfate and is collected on a filter paper. The lead sulfate
responsibility of the user of this standard to establish appro-
precipitate is covered with aluminum foil and held for 5 days
priate safety and health practices and determine the applica-
or longer for Bi ingrowth. It is then counted for beta
bility of regulatory limitations prior to use. For specific hazards
radiation on a gas flow proportional counter.
statements, see Section 9.
5. Significance and Use
2. Referenced Documents
5.1 This test method was developed to measure the concen-
2.1 ASTM Standards:
tration of Pb in nonprocess water samples. This test method
D1129 Terminology Relating to Water
may be used to determine the concentration of Pb in
D1193 Specification for Reagent Water
environmental samples.
D2777 Practice for Determination of Precision and Bias of
Applicable Test Methods of Committee D19 on Water
6. Interferences
D3370 Practices for Sampling Water from Closed Conduits
6.1 Significant amounts of stable lead (>0.3 mg/L) present
D4448 Guide for Sampling Ground-Water Monitoring Wells
in the sample will interfere with the chemical yield
D5847 Practice for Writing Quality Control Specifications
determination, leading to positive bias in the yield. If it is
for Standard Test Methods for Water Analysis
known or suspected that natural lead is present in the sample,
D6001 Guide for Direct-Push Groundwater Sampling for
blank sample aliquots to which no lead carrier content is added
Environmental Site Characterization
should be analyzed. The amount of natural lead contained in
D7282 Practice for Set-up, Calibration, and Quality Control
the sample shall be used to correct the yield.
of Instruments Used for Radioactivity Measurements
6.2 In most cases measurable amounts of Pb will be
present in the Pb carrier used in 12.1. This additional contri-
This test method is under the jurisdiction of ASTM Committee D19 on Water bution to the measured sample activity must be determined and
and is the direct responsibility of Subcommittee D19.04 on Methods of Radiochemi-
treated as additional background activity. For each new carrier
cal Analysis.
solution, the inherent Pb in the carrier must be measured. A
Current edition approved Jan. 1, 2015. Published January 2015. Originally
ε1
brief description of this additional background calibration is
approved in 2009. Last previous edition approved in 2009 as D7535 – 09 . DOI:
10.1520/D7535-09R15.
given in 11.2. Accurate determination of the combined stan-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
dard uncertainty and the minimum detectable concentration
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
should include this additional activity in the method back-
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. ground count rate.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D7535 − 09 (2015)
6.3 Previous experimental data suggests that barium con- and applied as a correction when calculating the test sample
centrations of approximately 30 ppm can be a source of result. This increased background reduces the sensitivity of the
interference, leading to chemical yield determinations that may measurement.
be non-representative and outside normal acceptance criteria.
8.2 Purity of Water—Unless otherwise indicated, reference
to water shall be understood to mean reagent water conforming
7. Apparatus
to Specification D1193, Type III.
7.1 Analytical Balance, 0.0001 g.
8.3 Ammonium hydroxide—15 M NH OH, (concentrated
NOTE 1—A thickness of aluminum of approximately 0.003 in. (areal
reagent).
density of approximately 0.02 mg/cm ) is needed to effectively eliminate
210 3
8.4 Iron Carrier (20 mg/mL)—Dissolve 9.6 g of ferric
the 60 keV beta particles from Pb. The thickness of aluminum foil
used during calibration of the detector and measurement samples must be
chloride (FeCl · 6H O) in 70 mL of 0.5 M HCl and dilute to
3 2
210 210
held constant to maintain self-absorption of Pb and Bi beta particles
100 mL with 0.5 M HCl.
at a constant level.
8.5 Nitric Acid, 16 M HNO —(concentrated reagent) (sp gr
7.2 Aluminum foil.
1.42).
7.3 Centrifuge.
8.5.1 Nitric Acid, 8 M HNO —Add 500 mL of concentrated
nitric acid to 400 mL water. Dilute to 1 L with water and mix
7.4 Centrifuge tubes (50 mL plastic).
well.
7.5 Filters, 25 mm polypropylene, 0.1 µm, with polycarbon-
8.5.2 Nitric Acid, 1 M HNO —Add 63 mL of concentrated
ate base and metal screen.
nitric acid to 800 mL water. Dilute to 1 L with water and mix
7.6 Filter apparatus, polysulfone funnel and 100 mL poly-
well.
propylene flask.
8.5.3 Nitric Acid, 0.1 M HNO —Add 6.4 mL of concen-
trated nitric acid to 600 mL water. Dilute to 1 L with water and
7.7 Beta Gas Flow Proportional Counting System, (<1.0
mix well.
cpm beta), low background.
8.6 Lead Carrier (10 grams Pb/L)—Dissolve 1.60 g of lead
7.8 Glass stir rods.
nitrate in water and dilute to 100 mL with water.
7.9 Glass beakers.
8.7 Lead Extraction Chromatography Column, 2-mL bed
7.10 Hot plate. 4
volume, 100–150 µm particle size.
7.11 Petri dish.
8.8 Pb-210 Standardizing Solution—Traceable to a national
7.12 Planchets, stainless steel, flat, with diameter large
standardizing laboratory such as National Institute of Standards
enough to hold the 25 mm filter.
and Technology, Gaithersburg, MD, USA (NIST) or National
Physical Laboratory, Teddington, Middlesex, UK, (NPL) with
7.13 Tweezers.
less than 0.1 mg of stable lead per mL of final solution with a
7.14 Watch glass. 210
typical Pb concentration range from 85 to 125 Bq/mL.
The Pb calibration source should be in equilibrium with its
8. Reagents and Materials
progeny Bi.
8.1 Purity of Reagents—Reagent grade chemicals shall be
8.9 Sulfuric Acid, 18 M H SO —concentrated reagent (sp gr
2 4
used in all tests. Unless otherwise indicated, it is intended that
1.84).
all reagents shall conform to the specifications of the Commit-
tee on Analytical Reagents of the American Chemical Society,
9. Hazards
where such specifications are available. Other grades may be
9.1 Use extreme caution when handling all acids. They are
used, provided that the reagent is of sufficiently high purity to
extremely corrosive, and skin contact could result in severe
permit its use without increasing the background of the
burns.
measurement. Some reagents, even those of high purity, may
9.2 When diluting concentrated acids, always use safety
contain naturally occurring radioactivity, such as isotopes of
glasses and protective clothing, and add the acid to the water.
uranium, radium, actinium, thorium, rare earths and potassium
compounds and/or artificially produced radionuclides.
10. Sampling
Consequently, when such reagents are used in the analysis of
10.1 Collect a sample in accordance with Guides D4448 and
low-radioactivity samples, the activity of the reagents shall be
D6001 and Practice D3370, or other documented procedure as
determined under analytical conditions that are identical to
appropriate.
those used for the sample. The activity contributed by the
reagents may be considered to be a component of background
Resin available in bulk form and in prepacked columns or cartridges from
Eichrom Technologies LLC, Lisle, IL 60532. If you are aware of alternative
Radiological Health Handbook, Revised Editions January 1970, Compiled and suppliers, please provide this information to ASTM International Headquarters.
Edited by the Bureau of Radiological Health and the Training Institute Environ- Your comments will receive careful consideration at a meeting of the responsible
mental Control Administration, US Department of Health, Education and Welfare. technical committee, which you may attend.
D7535 − 09 (2015)
2 2 2 2
11. Calibration u ~R !1u ~R ! R 2 R u ~m !
a b a b s
2 2 ˆ 2
u ε 5 1 3 1u ~F ! 3 DF
~ ! S S D D
c Bi 2 2 2 c c
m 3 IF m 3 IF m
s s s
11.1 Detection Effıciency Calibration (see also Practice
2 2 2 2 2 2
c 3V u ~c ! u ~V ! u ~c ! u ~V !
c c s s c c
D7282):
3 1ε 3 1 1 1
2 2 2 S 2 2 2 2 D
Bi
c 3V 3 DF c V c V
s s s s c c
11.1.1 Prepare a set of three working calibration sources
(2)
according to the calibration procedure outlined in the subse-
where u(·) denotes standard uncertainty; for example, u(V )
s
quent steps.
is the standard uncertainty of V .
s
11.1.2 Pipet 1.0 mL of lead carrier into a small beaker.
11.1.8.1 Eq 2 omits the uncertainties due to the activity
11.1.3 Add 1.0 mL of Pb standardizing solution to the
concentration of the calibration standard solution, c , and the
s
beaker and evaporate to near dryness on a hot plate at a low
concentration of the carrier solution, c . These uncertainty
c
setting.
components are accounted for when the average efficiency is
determined (below).
11.1.4 Redissolve the residue in 10 mL of 1 M HNO .
11.1.8.2 The procedure requires an average of (at least)
11.1.5 Follow the steps described in 12.9 through 12.28.
three efficiencies (N = 3) measured using three calibration
11.1.6 Count to amass at least 10 000 counts. Record the
sources on each detector. For this purpose, calculate ε , ε , ε
1 2 3
time and date of the midpoint of this counting period as t .
m
for each source, and use Eq 3 to calculate the weighted
11.1.7 Detection Effıciency Calculation—Calculate the de-
average:
tection efficiency for Bi for each calibration source and each
N
εH 5 ε (3)
detector using Eq 1.
Bi ( i
N
i51
R 2 R
a b
ε 5 (1) 11.1.8.3 To calculate the uncertainty of the average, includ-
Bi
c 3V 3 DF3 IF3Y
s s Pb
ing uncertainty components due to systematic errors, Eq 4 is
where: used:
ε = detection efficiency for Bi,
Bi N
2 2
–1 1 u ~c ! u ~c !
s c
2 2
R = total count rate (s ) for calibration source, (counts
a u~εH ! 5Œ u ~ε !1εH 3 1 (4)
2 S 2 2 D
Bi ( c i Bi
N c c
i51
s c
divided by count time (s))
–1 210
R = count rate (s ) for blank or background source, 11.2 Determination of Inherent Pb in Pb Carrier:
b
(counts divided by count time (s))
11.2.1 As noted in 6.2, in cases where the Pb carrier used in
210 210
IF = correction factor for ingrowth of Bi from Pb
this procedure has not been determined to be free of Pb,
between the time of the bismuth separation to the
the Pb content inherent in the lead carrier used in this
2λ ~t 2t !
Bi m s
midpoint of counting, 12e , where:
method must be evaluated. Each new carrier solution must be
210 210
210 –6 –1
measured for Pb prior to use. Once the Pb content of the
λ = decay constant for Bi, (1.60 × 10 s ),
Bi
t = date and time of Bi separation, and lead carrier is known, the Pb count rate from the recovered
s
t = midpoint of count of calibration mount (date and
lead carrier can be calculated for each sample analyzed. The
m
time).
following step provides a protocol to determine the inherent
DF = correction factor for decay of Pb in the carrier
210Pb in the lead carrier and Section 13 provides the equations
solution from the carrier activity reference date to the 210
needed to correct for the Pb inherent in the lead carrier. The
2λ t 2t
~ !
Pb s r
time of the bismuth separation,e , where:
specific number of samples, as well as acceptance criteria for
210 −10 −1
λ = decay constant for Pb, (9.85 × 10 s ),
Pb the data and statistical tests to determine detectable Pb in
t = reference date and time of Pb calibration of
r
the lead carrier, should be specified in the laboratory’s Quality
lead carrier, and
210 Systems Manual.
t = date and time of Bi separation.
s
11.2.2 To a minimum of five 50 mL centrifuge tubes, add 1
c = activity concentration (or massic activity) of the
s
mL of the Pb carrier solution.
calibration standard solution (Bq/unit),
11.2.3 Add 20 mL of water and 4 mL concentrated sulfuric
V = volume (or mass) of standard solution used (mL or g),
s
acid to each centrifuge tube.
Y = chemical yield of lead (see 13.1 and 13.2); Y
Pb Pb
11.2.4 Continue with the normal sample preparation, begin-
5m /~c 3V !, where:
s c c
ning at 12.16.
m = net mass (mg) of lead sulfate found in the
s
11.2.5 After counting, calculate for each sample the Pb
source, equal to m − m , where m is the total
F+P F F+P
mass of the filter plus precipitate and m is the tare concentration and associated uncertainty according to Section
F
mass (filter only),
13. Calculate the weighted average aˆ and standard uncertainty
c
c = mass concentration (mg/mL) of lead (as sulfate)
c
u(aˆ ) of the Pb concentration using the calculated sample
c
in the carrier solution (see Eq 5), and
results from the data set using the equations in 13.3.
V = volume of carrier solution added (mL).
c
Eq 1 assumes that any Pb activity contamination in the Pb
12. Procedure
carrier is insignificant compared to the amount of Pb activity NOTE 2—See Fig. 1 for a diagram of the procedur
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