Standard Test Method for Tritium in Drinking Water

SIGNIFICANCE AND USE
This test method was developed for measuring tritium in water to determine if the concentration exceeds the regulatory statutes of drinking water. This test method also is applicable for the determination of tritium concentration in water as required by technical specifications governing the operations of nuclear power facilities. With suitable counting technique, sample size, and counting time a detection limit of less than 37 Bq/L (1000 pCi/L) is attainable by liquid scintillation.
SCOPE
1.1 This test method covers the determination of tritium in drinking water (as T2O or HTO) by liquid scintillation counting of the tritium beta particle activity.
1.2 This test method is used successfully with drinking water. It is the user's responsibility to ensure the validity of this test method for waters of untested matrices.
1.3 The tritium concentrations, which can be measured by this test method utilizing currently available liquid scintillation instruments, range from less than 0.037 Bq/mL (1 pCi/mL) to 555 Bq/mL (15 000 pCi/mL) for a 10-mL sample aliquot. Higher tritium concentrations can be measured by diluting or using smaller sample aliquots, or both.
1.4 The maximum contaminant level for tritium in drinking water as given by the National Interim Primary Drinking Water Regulations (NIPDWR) is 0.740 Bq/mL (20 pCi/mL). The NIPDWR lists a required detection limit for tritium in drinking water of 0.037 Bq/mL (1 pCi/mL), meaning that drinking water supplies, where required, should be monitored for tritium at a sensitivity of 0.037 Bq/mL (1 pCi/mL). In , Eqn. 1 is given for determining the necessary counting time to meet the required sensitivity for drinking water monitoring.
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.

General Information

Status
Historical
Publication Date
09-Mar-1998
Technical Committee
Current Stage
Ref Project

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ASTM D4107-98(2002)e1 - Standard Test Method for Tritium in Drinking Water
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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
e1
Designation:D 4107–98 (Reapproved 2002)
Standard Test Method for
Tritium in Drinking Water
This standard is issued under the fixed designation D 4107; 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 (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Sections 1.4, 10.1.1, 10.1.2, and 12.3.1 were editorially updated in July 2002.
1. Scope D 3648 Practices for the Measurement of Radioactivity
1.1 This test method covers the determination of tritium in
3. Terminology
drinkingwater(asT OorHTO)byliquidscintillationcounting
3.1 Definitions—For definitions of terms used in this test
of the tritium beta particle activity.
method, refer to Terminology D 1129. For terms not defined in
1.2 This test method is used successfully with drinking
this test method or in Terminology D 1129, reference may be
water.Itistheuser’sresponsibilitytoensurethevalidityofthis
made to other published glossaries.
test method for waters of untested matrices.
1.3 The tritium concentrations, which can be measured by
4. Summary of Test Method
this test method utilizing currently available liquid scintillation
4.1 In this test method, a 100-mL drinking water sample
instruments, range from less than 0.037 Bq/mL (1 pCi/mL) to
aliquotistreatedwithasmallamountofsodiumhydroxideand
555 Bq/mL (15 000 pCi/mL) for a 10-mL sample aliquot.
potassium permanganate, distilled, and a specified fraction of
Higher tritium concentrations can be measured by diluting or
the distillate is collected for tritium analysis. The alkaline
using smaller sample aliquots, or both.
treatment is to prevent other radionuclides, such as radioiodine
1.4 The maximum contaminant level for tritium in drinking
and radiocarbon from distilling over with the tritium. Some
waterasgivenbytheNationalInterimPrimaryDrinkingWater
drinking water supplies will contain trace quantities of organic
Regulations (NIPDWR) is 0.740 Bq/mL (20 pCi/mL). The
compounds, especially surface water sources that contain fish
NIPDWR lists a required detection limit for tritium in drinking
and other life. The permanganate treatment is to oxidize trace
waterof0.037Bq/mL(1pCi/mL),meaningthatdrinkingwater
organics in the sample aliquots which could distill over and
supplies, where required, should be monitored for tritium at a
cause quenching interferences. A middle fraction of the distil-
sensitivity of 0.037 Bq/mL (1 pCi/mL). In Appendix X1,Eq
late is collected for tritium analysis because the early and late
X1.3 is given for determining the necessary counting time to
fractions are more apt to contain interfering materials for the
meet the required sensitivity for drinking water monitoring.
liquid scintillation counting process.
1.5 This standard does not purport to address all of the
4.2 As the sample distills, there is a gradient in the tritium
safety concerns, if any, associated with its use. It is the
concentration in the accumulating distillate; therefore, it is
responsibility of the user of this standard to establish appro-
important to collect the same fraction of the distillate for all
priate safety and health practices and determine the applica-
samples and standards for tritium analysis.
bility of regulatory limitations prior to use.
4.3 The collected distillate fraction is thoroughly mixed and
a portion (up to 10 mL) is mixed with liquid scintillator
2. Referenced Documents
solution, and after dark adapting, is counted in the liquid
2.1 ASTM Standards:
2 scintillation counting system for tritium beta particle activity.
D 1129 Terminology Relating to Water
D 1193 Specification for Reagent Water
5. Significance and Use
D 2777 Practice for Determination of Precision and Bias of
2 5.1 Thistestmethodwasdevelopedformeasuringtritiumin
Applicable Methods of Committee D19 on Water
water to determine if the concentration exceeds the regulatory
D 3370 Practices for Sampling Water from Closed Con-
2 statutes of drinking water. This test method also is applicable
duits
for the determination of tritium concentration in water as
requiredbytechnicalspecificationsgoverningtheoperationsof
This test method is under the jurisdiction of ASTM Committee D19 on Water
andisthedirectresponsibilityofSubcommitteeD19.04onMethodsofRadiochemi-
cal Analysis. Annual Book of ASTM Standards, Vol 11.02.
Current edition approved March 10, 1998. Published December 1998. Originally American National Glossary of Terms in Nuclear Science and Technology,
published as D 4107 – 91. Last previous edition D 4107 – 98. available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th
Annual Book of ASTM Standards, Vol 11.01. Floor, New York, NY 10036.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
e1
D 4107–98 (2002)
nuclear power facilities. With suitable counting technique, 8.3.1 Sodium Hydroxide Pellets.
sample size, and counting time a detection limit of less than 37 8.3.2 Potassium Permanganate.
Bq/L (1000 pCi/L) is attainable by liquid scintillation. 8.4 Background Water, with tritium activity below the
minimum detectable activity (most deep well waters are low in
6. Interferences
tritium content).
6.1 A reduced counting efficiency may result from quench-
8.5 Scintillator Solutions:
ing in the sample scintillator mixture. Quenching is caused by 8.5.1 Dioxane Liquid Scintillator Solution—Dissolve4gof
impurities in the sample, which can inhibit the transfer of
scintillation-grade PPO (2,5-diphenyloxazole), 0.05 g of
energy, or by colored materials, which may absorb some of the scintillation-grade POPOP [1,4-bis (5-phenyloxazolyl-2-yl)-
emitted light. Corrections for quenching can be made by the
benzene], and 120 g of naphthalene in 1 L of spectroquality,
4 5
use of internal standards or by the ratio method. The 1,4-dioxane. Store the solution in a dark (amber) bottle. This
approach described in this test method, distillation after alka-
solution can be used with glass or polyethylene vials.
line permanganate treatment, eliminates quenching substances, 8.5.2 Solution G Scintillator Solution—Dissolve 18 g of
as well as radionuclides which might be present in a volatile
scintillation-grade PPO (2,5-diphenyloxazole) and 3.6 g of
chemical form such as radioiodine and radiocarbon. A boiling
scintillation-grade BIS-MSB [p-bis (o-methylstyryl) benzene]
chip must be used with each distillation to avoid bumping, in 2 L of spectroquality p-xylene. Add 1 L of Triton N-101
which can amount to a carry over excursion.
detergent to the p-xylene scintillator solution. Dissolve 50 g of
6.2 Scintillator stock solution or samples exposed to day- SXS (sodium xylene sulfonate) in 100 mL of water and add
light must be dark-adapted. Also, toluene or xylene base
this solution to the p-xylene scintillator-Triton solution. Mix
scintillators exposed to fluorescent lighting should be dark- thoroughly. Store the solution in a dark (amber) bottle. This
adapted for a minimum of 6 h and dioxane base scintillators
solution should be used with glass vials since the p-xylene
exposed to fluorescent lighting for 24 h. All fluors should he solvent evaporates slowly through the wall of the polyethylene
checked for excitation under lighting conditions being used,
vials.
and if possible, they should be exposed only to red light. 8.5.3 Other commercially available scintillators can be
used, such as the environmentally safe di-isopropyl napthalene
7. Apparatus
based scintillators. It is the responsibility of the user to verify
7.1 Liquid Scintillation Spectrometer, coincidence-type.
the acceptability of a substitute scintillator.
7.2 Liquid Scintillation Vials, of low-potassium glass are
9. Sampling
recommended. Polyethylene vials may be used when dioxane
scintillator solution is used.
9.1 CollectthesampleinaccordancewithPracticesD 3370.
7.3 Distillation Apparatus—For aqueous distillation,
9.2 Sincetritiumindrinkingwaterislikelytobeintheform
250-mL and 1000-mL round bottom borosilicate flasks, con-
of T O or HTO, there is no need for special handling or
necting side arm adapter, condenser, graduated cylinder,
preservation.
boiling chips, and heating mantle.
10. Calibration
8. Reagents and Materials
10.1 Determination of Recovery and Counting Effıciency
8.1 Purity of Reagents—Reagent grade chemicals shall be
Factors:
used in all tests. Unless otherwise indicated, it is intended that
10.1.1 Prepare in a 1-L volumetric flask, a tritium standard
all reagents shall conform to the specifications of the Commit-
solution containing approximately 17 disintegrations/s
tee onAnalytical Reagents of theAmerican Chemical Society,
(dps)/mL using low level tritium background raw water (un-
where such specifications are available. Other grades may be
distilled) and standard tritium activity. Label this solution as
used, provided it is first ascertained that the reagent is of
raw water tritium standard solution. Distill approximately 600
sufficiently high purity to permit its use without lessening the
mL of water obtained from the same raw water source (RWS)
accuracy of the determination.
as above (without tritium activity added).
8.1.1 All chemicals should be of reagent-grade or equiva-
10.1.1.1 Use this distillate for background tritium determi-
lent whenever they are commercially available.
nations. Using the distillate and standard tritium activity,
8.2 Purity of Water—Unless otherwise indicated, references
prepare a tritium standard solution in a 500-mL volumetric
towatershallbeunderstoodtomeanreagentwaterconforming
flask to contain the same specific activity as the raw water
to Specification D 1193, Type III.
tritium standard solution. Label this solution as distilled water
8.3 Reagents of Distillation Treatment:
tritium standard solution.
10.1.2 Aqueous Alkaline Permanganate Distillation—Place
a 100-mL aliquot of the raw water tritium standard solution in
Bush,E.T.,“GeneralApplicabilityoftheChannelsRadioMethod
...

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