Water quality - Carbon 14 - Test method using liquid scintillation counting (ISO 13162:2021)

This document specifies a method for the measurement of 14C activity concentration in all types of
water samples by liquid scintillation counting (LSC) either directly on the test sample or following a
chemical separation.
The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water,
marine water, as well as cooling water, industrial water, domestic, and industrial wastewater.
The detection limit depends on the sample volume, the instrument used, the sample counting time, the
background count rate, the detection efficiency and the chemical recovery. The method described in
this document, using currently available liquid scintillation counters and suitable technical conditions,
has a detection limit as low as 1 Bq∙l−1, which is lower than the WHO criteria for safe consumption of
drinking water (100 Bq·l-1). 14C activity concentrations can be measured up to 106 Bq∙l-1 without any
sample dilution.
It is the user’s responsibility to ensure the validity of this test method for the water samples tested.

Wasserbeschaffenheit - Kohlenstoff-14 - Verfahren mit dem Flüssigszintillationszähler (ISO 13162:2021)

Dieses Dokument legt ein Verfahren zur Messung der 14C-Aktivitätskonzentration in allen Arten von Wasserproben mittels Flüssigszintillationszähler (LSC, en: liquid scintillation counting) fest, entweder direkt an der Messprobe oder nach einer chemischen Trennung.
Dieses Verfahren ist auf Messproben von Versorgungs-/Trinkwasser, Regenwasser, Oberflächen- und Grundwasser, Meerwasser sowie Kühlwasser, Prozesswasser, häusliches und gewerbliches Abwasser anzuwenden.
Die Nachweisgrenze hängt vom Probenvolumen, dem eingesetzten Messgerät, der Messdauer der Probe, der Zählrate des Nulleffekts, der Zählausbeute und der chemischen Wiederfindung ab. Das in diesem Dokument beschriebene Verfahren hat, bei Verwendung der derzeit verfügbaren Flüssigszintillationszähler und unter geeigneten technischen Bedingungen, eine Nachweisgrenze von nur 1 Bq∙l−1, was unter den WHO-Kriterien für den sicheren Verzehr von Trinkwasser (100 Bq∙l−1) liegt. 14C-Aktivitätskonzentrationen können ohne Probenverdünnung bis 106 Bq∙l−1 gemessen werden.
Es liegt in der Verantwortung des Anwenders, die Validität dieses Prüfverfahrens für die geprüften Wasserproben sicherzustellen.

Qualité de l’eau - Carbone 14 - Méthode d’essai par comptage des scintillations en milieu liquide (ISO 13162:2021)

Kakovost vode - Ogljik C-14 - Preskusna metoda s štetjem s tekočinskim scintilatorjem (ISO 13162:2021)

General Information

Status
Published
Technical Committee
Current Stage
6060 - Definitive text made available (DAV) - Publishing
Due Date
16-Jun-2021
Completion Date
16-Jun-2021

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SLOVENSKI STANDARD
SIST EN ISO 13162:2021
01-september-2021
Nadomešča:
SIST EN ISO 13162:2015
SIST ISO 13162:2013
Kakovost vode - Ogljik C-14 - Preskusna metoda s štetjem s tekočinskim
scintilatorjem (ISO 13162:2021)
Water quality - Carbon 14 - Test method using liquid scintillation counting (ISO
13162:2021)

Wasserbeschaffenheit - Kohlenstoff-14 - Verfahren mit dem Flüssigszintillationszähler

(ISO 13162:2021)

Qualité de l’eau - Carbone 14 - Méthode d’essai par comptage des scintillations en

milieu liquide (ISO 13162:2021)
Ta slovenski standard je istoveten z: EN ISO 13162:2021
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
SIST EN ISO 13162:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN ISO 13162:2021
---------------------- Page: 2 ----------------------
SIST EN ISO 13162:2021
EN ISO 13162
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2021
EUROPÄISCHE NORM
ICS 13.060.60; 17.240 Supersedes EN ISO 13162:2015
English Version
Water quality - Carbon 14 - Test method using liquid
scintillation counting (ISO 13162:2021)

Qualité de l'eau - Carbone 14 - Méthode d'essai par Wasserbeschaffenheit - Kohlenstoff-14 - Verfahren mit

comptage des scintillations en milieu liquide (ISO dem Flüssigszintillationszähler (ISO 13162:2021)

13162:2021)
This European Standard was approved by CEN on 13 May 2021.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this

European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists in three official versions (English, French, German). A version in any other language made by

translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 13162:2021 E

worldwide for CEN national Members.
---------------------- Page: 3 ----------------------
SIST EN ISO 13162:2021
EN ISO 13162:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

---------------------- Page: 4 ----------------------
SIST EN ISO 13162:2021
EN ISO 13162:2021 (E)
European foreword

This document (EN ISO 13162:2021) has been prepared by Technical Committee ISO/TC 147 "Water

quality" in collaboration with Technical Committee CEN/TC 230 “Water analysis” the secretariat of

which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by December 2021, and conflicting national standards

shall be withdrawn at the latest by December 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 13162:2015.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 13162:2021 has been approved by CEN as EN ISO 13162:2021 without any modification.

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SIST EN ISO 13162:2021
---------------------- Page: 6 ----------------------
SIST EN ISO 13162:2021
INTERNATIONAL ISO
STANDARD 13162
Second edition
2021-06
Water quality — Carbon 14 — Test
method using liquid scintillation
counting
Qualité de l’eau — Carbone 14 — Méthode d’essai par comptage des
scintillations en milieu liquide
Reference number
ISO 13162:2021(E)
ISO 2021
---------------------- Page: 7 ----------------------
SIST EN ISO 13162:2021
ISO 13162:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 13162:2021
ISO 13162:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms, definitions, symbols and abbreviations ................................................................................................................... 2

4 Principle ........................................................................................................................................................................................................................ 3

5 Sampling and storage ...................................................................................................................................................................................... 4

5.1 Sampling ....................................................................................................................................................................................................... 4

5.2 Sample storage ........................................................................................................................................................................................ 4

6 Reagents and equipment ............................................................................................................................................................................. 4

6.1 Reagents........................................................................................................................................................................................................ 4

6.1.1 Reference water for the blank .............................................................................................................................. 4

6.1.2 Calibration source solution ..................................................................................................................................... 4

6.1.3 Scintillation solution..................................................................................................................................................... 5

6.1.4 Quenching agent............................................................................................................................................................... 5

6.2 Equipment ................................................................................................................................................................................................... 5

7 Procedure..................................................................................................................................................................................................................... 5

7.1 Sample preparation ............................................................................................................................................................................ 5

7.2 Preparation of the counting vial .............................................................................................................................................. 5

7.3 Counting procedure ............................................................................................................................................................................ 6

7.4 Calibration and verification ......................................................................................................................................................... 6

7.5 Measurement conditions ......... ....................................................................................................................................................... 7

8 Expression of results ........................................................................................................................................................................................ 7

8.1 General ........................................................................................................................................................................................................... 7

8.2 Calculation of activity concentration without sample preparation ........................................................... 7

8.3 Calculation of activity concentration with sample preparation ................................................................... 8

8.4 Decision threshold ............................................................................................................................................................................... 8

8.5 Detection limit ......................................................................................................................................................................................... 9

8.6 Limits of the coverage intervals ............................................................................................................................................... 9

8.6.1 Limits of the probabilistically symmetric coverage interval...................................................... 9

8.6.2 Limits of the shortest coverage interval ...................................................................................................... 9

8.7 Calculations using the activity per mass ........................................................................................................................10

9 Test report ................................................................................................................................................................................................................10

Annex A (informative) Extraction of total carbon by precipitation of calcium carbonate ........................12

Annex B (informative) Extraction of total carbon: absorption counting .....................................................................15

Annex C (informative) Internal standard method ...............................................................................................................................18

Annex D (informative) Numerical applications .....................................................................................................................................20

Bibliography .............................................................................................................................................................................................................................22

© ISO 2021 – All rights reserved iii
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SIST EN ISO 13162:2021
ISO 13162:2021(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/

iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 3,

Radioactivity measurements, in collaboration with the European Committee for Standardization (CEN)

Technical Committee CEN/TC 230, Water analysis, in accordance with the Agreement on technical

cooperation between ISO and CEN (Vienna Agreement).

This second edition cancels and replaces the first edition (ISO 13162:2011), which has been technically

revised. The main changes compared to the previous edition are as follows:
— Introduction developed;
— Scope updated;
— References updated;
— Sample preparation revised.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved
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SIST EN ISO 13162:2021
ISO 13162:2021(E)
Introduction

Radioactivity from several naturally-occurring and anthropogenic sources is present throughout

the environment. Thus, water bodies (e.g. surface waters, ground waters, sea waters) can contain

radionuclides of natural, human-made, or both origins:
40 3 14

— natural radionuclides, including K, H, C, and those originating from the thorium and uranium

226 228 234 238 210 210
decay series, in particular Ra, Ra, U, U, Po and Pb can be found in water for

natural reasons (e.g. desorption from the soil and washoff by rain water) or can be released from

technological processes involving naturally occurring radioactive materials (e.g. the mining and

processing of mineral sands or phosphate fertilizers production and use);

— human-made radionuclides such as transuranium elements (americium, plutonium, neptunium,

3 14 90

curium), H, C, Sr, and gamma emitting radionuclides can also be found in natural waters.

Small quantities of these radionuclides are discharged from nuclear fuel cycle facilities into the

environment as a result of authorized routine releases. Some of these radionuclides used for

medical and industrial applications are also released into the environment after use. Anthropogenic

radionuclides are also found in waters as a result of past fallout contaminations resulting from

the explosion in the atmosphere of nuclear devices and accidents such as those that occurred in

Chernobyl and Fukushima.

Radionuclide activity concentration in water bodies can vary according to local geological

characteristics and climatic conditions and can be locally and temporally enhanced by releases from

[1]

nuclear installation during planned, existing, and emergency exposure situations. Drinking-water

may thus contain radionuclides at activity concentrations which could present a risk to human health.

The radionuclides present in liquid effluents are usually controlled before being discharged into

[2]

the environment and water bodies. Drinking waters are monitored for their radioactivity as

[3]

recommended by the World Health Organization (WHO) so that proper actions can be taken to ensure

that there is no adverse health effect to the public. Following these international recommendations,

national regulations usually specify radionuclide authorized concentration limits for liquid effluent

discharged to the environment and radionuclide guidance levels for waterbodies and drinking waters

for planned, existing, and emergency exposure situations. Compliance with these limits can be assessed

using measurement results with their associated uncertainties as specified by ISO/IEC Guide 98-3 and

[4]
ISO 5667-20 .

Depending on the exposure situation, there are different limits and guidance levels that would result

in an action to reduce health risk. As an example, during a planned or existing situation, the WHO

-1 14

guidelines for guidance level in drinking water is 100 Bq∙l for C activity concentration.

NOTE 1 The guidance level is the activity concentration with an intake of 2 l/d of drinking water for one year

that results in an effective dose of 0,1 mSv/a for members of the public. This is an effective dose that represents a

[3]

very low level of risk and which is not expected to give rise to any detectable adverse health effects .

[5]

In the event of a nuclear emergency, the WHO Codex Guideline Levels mentioned that the activity

-1 14

concentration might not be greater than 10 000 Bq∙l for C in foods other than for infant foods.

NOTE 2 The Codex guidelines levels (GLs) apply to radionuclides contained in foods destined for human

consumption and traded internationally, which have been contaminated following a nuclear or radiological

emergency. These GLs apply to food after reconstitution or as prepared for consumption, i.e., not to dried or

concentrated foods, and are based on an intervention exemption level of 1 mSv in a year for members of the

[5]
public (infant and adult) .

Thus, the test method can be adapted so that the characteristic limits, decision threshold, detection

limit and uncertainties ensure that the radionuclide activity concentrations test results can be verified

to be below the guidance levels required by a national authority for either planned/existing situations

[6][7]
or for an emergency situation .

Usually, the test methods can be adjusted to measure the activity concentration of the radionuclide(s)

in either wastewaters before storage or in liquid effluents before being discharged to the environment.

© ISO 2021 – All rights reserved v
---------------------- Page: 11 ----------------------
SIST EN ISO 13162:2021
ISO 13162:2021(E)

The test results will enable the plant/installation operator to verify that, before their discharge,

wastewaters/liquid effluent radioactive activity concentrations do not exceed authorized limits.

The test method(s) described in this document may be used during planned, existing and emergency

exposure situations as well as for wastewaters and liquid effluents with specific modifications that

could increase the overall uncertainty, detection limit, and threshold.

The test method(s) may be used for water samples after proper sampling, sample handling, and test

sample preparation (see the relevant part of the ISO 5667 series).

This document has been developed to support the need of test laboratories carrying out these

measurements, that are sometimes required by national authorities, as they may have to obtain a

specific accreditation for radionuclide measurement in drinking water samples.

This document is one of a set of International Standards on test methods dealing with the measurement

of the activity concentration of radionuclides in water samples.
vi © ISO 2021 – All rights reserved
---------------------- Page: 12 ----------------------
SIST EN ISO 13162:2021
INTERNATIONAL STANDARD ISO 13162:2021(E)
Water quality — Carbon 14 — Test method using liquid
scintillation counting

WARNING — Persons using this document should be familiar with normal laboratory practice.

This document does not purport to address all of the safety problems, if any, associated with its

use. It is the responsibility of the user to establish appropriate safety and health practices and to

determine the applicability of any other restrictions.

IMPORTANT — It is absolutely essential that tests conducted according to this document be

carried out by suitably trained staff.
1 Scope

This document specifies a method for the measurement of C activity concentration in all types of

water samples by liquid scintillation counting (LSC) either directly on the test sample or following a

chemical separation.

The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water,

marine water, as well as cooling water, industrial water, domestic, and industrial wastewater.

The detection limit depends on the sample volume, the instrument used, the sample counting time, the

background count rate, the detection efficiency and the chemical recovery. The method described in

this document, using currently available liquid scintillation counters and suitable technical conditions,

has a detection limit as low as 1 Bq∙l , which is lower than the WHO criteria for safe consumption of

-1 14 6 -1

drinking water (100 Bq·l ). C activity concentrations can be measured up to 10 Bq∙l without any

sample dilution.

It is the user’s responsibility to ensure the validity of this test method for the water samples tested.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and

sampling techniques

ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples

ISO 5667-10, Water quality — Sampling — Part 10: Guidance on sampling of waste water

ISO 11929-1, Determination of the characteristic limits (decision threshold, detection limit and limits of

the coverage interval) for measurements of ionizing radiation — Fundamentals and application — Part 1:

Elementary applications

ISO 19361, Measurement of radioactivity — Determination of beta emitters activities — Test method using

liquid scintillation counting
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty

in measurement (GUM: 1995) — Part 3: Guide to the expression of uncertainty in measurement (GUM: 1995)

© ISO 2021 – All rights reserved 1
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SIST EN ISO 13162:2021
ISO 13162:2021(E)

ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and

associated terms (VIM)
3 Terms, definitions, symbols and abbreviations

For the purposes of this document, the definitions, symbols and abbreviations given

in ISO/IEC Guide 99:2007, ISO/IEC Guide 98-3:2008, ISO 80000-10, and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
β Maximum energy for the beta emission keV
max
Volume of laboratory sample l
Mass of laboratory sample kg
Density of the sample kg∙l
c Activity concentration Bq∙l
Activity per unit of mass Bq∙kg
A Activity of the calibration source Bq
A Activity of the internal standard solution Bq
n Number of counting -
N Number of the counted pulses for the background -
t Background counting time, in second s
N Number of the counted pulses for the sample -
t Sample counting time s
t Calibration counting time s
r Background count rate s
r Test sample count rate s
r Calibration count rate s
Detection efficiency -
Q Quench parameter -
f Quench factor -
ε Counting efficiency at quench parameter Q -
R Chemical recovery -
m Mass of total carbon in the sample kg
m Mass of carbon in the precipitate kg
m Mass of carbon in the carrier kg
m Mass of sample carbon in the precipitate kg
Standard uncertainty associated with the measurement result Bq∙l
uc()
u Relative standard uncertainty -
rel
c Possible or assumed true quantity values of the measurand Bq∙l
  Standard uncertainty of c Bq∙l
uc()
α, β Probability of a false positive and false negative decision, respectively -
2 © ISO 2021 – All rights reserved
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SIST EN ISO 13162:2021
ISO 13162:2021(E)
k Quantile of the standardized normal distribution for the probability 1- α -
1−α
k Quantile of the standardized normal distribution for the probability 1- β -
1−β
Decision threshold Bq∙l
Detection limit Bq∙l
Lower and upper limits of the probabilistically symmetric coverage interval Bq∙l
cc,
Lower and upper limits of the shortest coverage interval Bq∙l
cc,
 
γ/2 Probability of the measurand being smaller than c or larger than c
A A
1− γ Probability for the coverage interval of the measurand -
Φ Distribution function of the standardized normal distribution -
Distribution function of the standardized normal distribution of c /uc
ω ()
A A

Quantiles of the standardized normal distribution for the probabilities p and q, re- -

k k
p, q
spectively
Bq∙l
U Expanded uncertainty, calculated by Uk=⋅uc() with k = 1, 2,…
4 Principle

The method described is for measurement of C in water samples by direct liquid scintillation counting.

The general principles of this method are described in ISO 19361.

This direct determination is applicable to the analysis of water samples that can produce a homogeneous

mixture between the test portion and a suitable scintillation cocktail.

The direct LSC method does not apply to waters containing micelles or large organic molecules

(e.g. lipids, fulvic acid, humic acid, etc.) that do not form homogeneous mixtures with scintillation

cocktails. In these cases, there is a risk that the beta particles could be attenuated. This reduces the

counting efficiency of the system and hence the results can be underestimated. For these samples,

the determination of C requires additional chemical processing (such as chemical oxidation or

combustion). Examples of methods of chemical preparation are described in Annexes A and B.

The choice of the analytical procedure (either with or without chemical preparation of the water sample

[17][18]

prior to determination) depends on the aim of the measurement and the sample characteristics

[19][20]

A prerequisite for the direct determination of C in a water sample is the absence of, or a negligible

contribution from, other beta-emitting radionuclides, such as Sr and Ra isotopes. When the

radionuclide content of the sample is unknown, the method specified in this document only provides a

C equivalent activity for the sample.

To determine the background count rate, a blank sample is prepared in the same way as the test portion.

The blank sample is prepared using a reference water of the lowest activity available, also sometimes

called “dead water”.
To determine the detection
...

SLOVENSKI STANDARD
oSIST prEN ISO 13162:2020
01-marec-2020
Kakovost vode - Ogljik C-14 - Preskusna metoda s štetjem s tekočinskim
scintilatorjem (ISO/DIS 13162:2020)

Water quality - Carbon 14 - Test method using liquid scintillation counting (ISO/DIS

13162:2020)

Wasserbeschaffenheit - Kohlenstoff-14 - Verfahren mit dem Flüssigszintillationszähler

(ISO/DIS 13162:2020)

Qualité de l’eau - Carbone 14 - Méthode d’essai par comptage des scintillations en

milieu liquide (ISO/DIS 13162:2020)
Ta slovenski standard je istoveten z: prEN ISO 13162
ICS:
13.060.60 Preiskava fizikalnih lastnosti Examination of physical
vode properties of water
17.240 Merjenje sevanja Radiation measurements
oSIST prEN ISO 13162:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
oSIST prEN ISO 13162:2020
---------------------- Page: 2 ----------------------
oSIST prEN ISO 13162:2020
DRAFT INTERNATIONAL STANDARD
ISO/DIS 13162
ISO/TC 147/SC 3 Secretariat: AFNOR
Voting begins on: Voting terminates on:
2020-01-28 2020-04-21
Water quality — Carbon 14 — Test method using liquid
scintillation counting
ICS: 17.240; 13.060.60
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 13162:2020(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. ISO 2020
---------------------- Page: 3 ----------------------
oSIST prEN ISO 13162:2020
ISO/DIS 13162:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting

on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
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oSIST prEN ISO 13162:2020
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Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Symbols, definitions, units, and abbreviations ..................................................................................................................... 2

4 Principle ........................................................................................................................................................................................................................ 3

5 Sampling and storage ...................................................................................................................................................................................... 3

5.1 Sampling ....................................................................................................................................................................................................... 3

5.2 Sample storage ........................................................................................................................................................................................ 3

6 Reagents and equipment ............................................................................................................................................................................. 4

6.1 Reagents........................................................................................................................................................................................................ 4

6.1.1 Reference water for the blank .............................................................................................................................. 4

6.1.2 Calibration source solution ..................................................................................................................................... 4

6.1.3 Scintillation solution..................................................................................................................................................... 4

6.1.4 Quenching agent............................................................................................................................................................... 5

6.2 Equipment ................................................................................................................................................................................................... 5

7 Procedure..................................................................................................................................................................................................................... 5

7.1 Sample preparation ............................................................................................................................................................................ 5

7.2 Preparation of the counting vial .............................................................................................................................................. 5

7.3 Counting procedure ............................................................................................................................................................................ 5

7.4 Calibration and verification ......................................................................................................................................................... 5

7.5 Measurement conditions ......... ....................................................................................................................................................... 6

8 Expression of results ........................................................................................................................................................................................ 7

8.1 General ........................................................................................................................................................................................................... 7

8.2 Calculation of activity concentration without sample preparation ........................................................... 7

8.3 Calculation of activity concentration with sample preparation ................................................................... 7

8.4 Decision threshold ............................................................................................................................................................................... 8

8.5 Detection limit ......................................................................................................................................................................................... 8

8.6 Limits of the coverage intervals ............................................................................................................................................... 9

8.6.1 Limits of the probabilistically symmetric coverage interval...................................................... 9

8.6.2 Limits of the shortest coverage interval ...................................................................................................... 9

8.7 Calculations using the activity per mass ........................................................................................................................10

9 Test report ................................................................................................................................................................................................................10

Annex A (informative) Numerical applications ......................................................................................................................................12

Annex B (informative) Internal standard method ...............................................................................................................................14

Annex C (informative) Extraction of total carbon by precipitation of calcium carbonate .........................16

Annex D (informative) Extraction of total carbon: absorption counting .....................................................................19

Bibliography .............................................................................................................................................................................................................................22

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oSIST prEN ISO 13162:2020
ISO/DIS 13162:2020(E)
Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards

bodies (ISO member bodies). The work of preparing International Standards is normally carried out

through ISO technical committees. Each member body interested in a subject for which a technical

committee has been established has the right to be represented on that committee. International

organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.

ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of

electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are

described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the

different types of ISO documents should be noted. This document was drafted in accordance with the

editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of

any patent rights identified during the development of the document will be in the Introduction and/or

on the ISO list of patent declarations received (see www .iso .org/ patents).

Any trade name used in this document is information given for the convenience of users and does not

constitute an endorsement.

For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to the

World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following

URL: www .iso .org/ iso/ foreword .html.

This document was prepared by Technical Committee ISO/TC 147, Water quality, Subcommittee SC 3,

Radioactivity measurements.

This second edition cancels and replaces the first edition (ISO 13162:2011), [Clauses 1, 2, 3, 4, 6 /

subclause 7.1] of which have been technically revised.
The main changes compared to the previous edition are as follows:
— Introduction developed;
— Scope updated;
— References updated;
— Sample preparation revised.
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Introduction

Radioactivity from several naturally-occurring and anthropogenic sources is present throughout

the environment. Thus, water bodies (e.g. surface waters, ground waters, sea waters) can contain

radionuclides of natural, human-made, or both origins:
40 3 14

— natural radionuclides, including K, H, C, and those originating from the thorium and uranium

226 228 234 238 210 210
decay series, in particular Ra, Ra, U, U, Po and Pb can be found in water for

natural reasons (e.g. desorption from the soil and washoff by rain water) or can be released from

technological processes involving naturally occurring radioactive materials (e.g. the mining and

processing of mineral sands or phosphate fertilizers production and use);

— human-made radionuclides such as transuranium elements (americium, plutonium, neptunium,

3 14 90

curium), H, C, Sr, and gamma emitting radionuclides can also be found in natural waters.

Small quantities of these radionuclides are discharged from nuclear fuel cycle facilities into the

environment as a result of authorized routine releases. Some of these radionuclides used for

medical and industrial applications are also released into the environment after use. Anthropogenic

radionuclides are also found in waters as a result of past fallout contaminations resulting from

the explosion in the atmosphere of nuclear devices and accidents such as those that occurred in

Chernobyl and Fukushima.

Radionuclide activity concentration in water bodies can vary according to local geological

characteristics and climatic conditions and can be locally and temporally enhanced by releases from

[1]

nuclear installation during planned, existing, and emergency exposure situations. Drinking-water

may thus contain radionuclides at activity concentrations which could present a risk to human health.

The radionuclides present in liquid effluents are usually controlled before being discharged into

[2]

the environment and water bodies. Drinking waters are monitored for their radioactivity as

[3]

recommended by the World Health Organization (WHO) so that proper actions can be taken to ensure

that there is no adverse health effect to the public. Following these international recommendations,

national regulations usually specify radionuclide authorized concentration limits for liquid effluent

discharged to the environment and radionuclide guidance levels for waterbodies and drinking waters

for planned, existing, and emergency exposure situations. Compliance with these limits can be assessed

using measurement results with their associated uncertainties as specified by ISO/IEC Guide 98-3 and

[4]
ISO 5667-20 .

Depending on the exposure situation, there are different limits and guidance levels that would result

in an action to reduce health risk. As an example, during a planned or existing situation, the WHO

-1 14

guidelines for guidance level in drinking water is 100 Bq l for C activity concentration.

NOTE 1 The guidance level is the activity concentration with an intake of 2 l/d of drinking water for one year

that results in an effective dose of 0,1 mSv/a for members of the public. This is an effective dose that represents a

[3]

very low level of risk and which is not expected to give rise to any detectable adverse health effects .

[6]

In the event of a nuclear emergency, the WHO Codex Guideline Levels mentioned that the activity

-1 14

concentration might not be greater than 10000 Bq l for C in foods other than for infant foods.

NOTE 2 The Codex guidelines levels (GLs) apply to radionuclides contained in foods destined for human

consumption and traded internationally, which have been contaminated following a nuclear or radiological

emergency. These GLs apply to food after reconstitution or as prepared for consumption, i.e., not to dried or

concentrated foods, and are based on an intervention exemption level of 1 mSv in a year for members of the

[5]
public (infant and adult) .

Thus, the test method can be adapted so that the characteristic limits, decision threshold, detection

limit and uncertainties ensure that the radionuclide activity concentrations test results can be verified

to be below the guidance levels required by a national authority for either planned/existing situations

[6][7].
or for an emergency situation

Usually, the test methods can be adjusted to measure the activity concentration of the radionuclide(s)

in either wastewaters before storage or in liquid effluents before being discharged to the environment.

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The test results will enable the plant/installation operator to verify that, before their discharge,

wastewaters/liquid effluent radioactive activity concentrations do not exceed authorized limits.

The test method(s) described in this document may be used during planned, existing and emergency

exposure situations as well as for wastewaters and liquid effluents with specific modifications that

could increase the overall uncertainty, detection limit, and threshold.

The test method(s) may be used for water samples after proper sampling, sample handling, and test

sample preparation (see the relevant part of the ISO 5667 series).

An International Standard on a test method of C activity concentrations in water samples is justified

for test laboratories carrying out these measurements, required sometimes by national authorities,

as laboratories may have to obtain a specific accreditation for radionuclide measurement in drinking

water samples.

This document is one of a set of International Standards on test methods dealing with the measurement

of the activity concentration of radionuclides in water samples.
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oSIST prEN ISO 13162:2020
DRAFT INTERNATIONAL STANDARD ISO/DIS 13162:2020(E)
Water quality — Carbon 14 — Test method using liquid
scintillation counting

WARNING — Persons using this document should be familiar with normal laboratory practice.

This document does not purport to address all of the safety problems, if any, associated with its

use. It is the responsibility of the user to establish appropriate safety and health practices.

IMPORTANT — It is absolutely essential that tests conducted according to this document be

carried out by suitably trained staff.
1 Scope

This document specifies a method for the measurement of C activity concentration in all types of

water samples by liquid scintillation counting either directly on the test sample or following a chemical

separation.

The method is applicable to test samples of supply/drinking water, rainwater, surface and ground water,

marine water, as well as cooling water, industrial water, domestic, and industrial wastewater.

The detection limit depends on the sample volume, the instrument used, the sample counting time, the

background count rate, the detection efficiency and the chemical recovery. The method described in

this document, using currently available liquid scintillation counters and suitable technical conditions

has a detection limit as low as 1 Bq l , which is lower than the WHO criteria for safe consumption of

-1 14 6 -1

drinking water (100 Bq·l ). C activity concentrations can be measured up to 10 Bq l without any

sample dilution.

It is the user’s responsibility to ensure the validity of this test method for the water samples tested.

2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 5667-1, Water quality — Sampling — Part 1: Guidance on the design of sampling programmes and

sampling techniques

ISO 5667-3, Water quality — Sampling — Part 3: Preservation and handling of water samples

ISO 5667-10, Water quality — Sampling — Part 10: Guidance on sampling of waste waters

ISO 11929, Determination of the characteristic limits (decision threshold, detection limit and

limits of the coverage interval) for measurements of ionizing radiation — Fundamentals and

application —Part 1: Elementary applications

ISO/IEC 17025, General requirements for the competence of testing and calibration laboratories

ISO 19361, Measurement of radioactivity — Determination of beta emitters activities — Test method using

liquid scintillation counting
ISO 80000-10, Quantities and units — Part 10: Atomic and nuclear physics

ISO/IEC Guide 98-3:2008, Uncertainty of measurement — Part 3: Guide to the expression of uncertainty in

me a s ur ement (GUM: 1995)
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ISO/IEC Guide 99:2007, International vocabulary of metrology — Basic and general concepts and

associated terms (VIM)
3 Symbols, definitions, units, and abbreviations

For the purposes of this document, the definitions, symbols and abbreviations defined

in ISO/IEC Guide 99:2007, ISO/IEC Guide 98-3:2008, ISO 80000-10, and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
β Maximum energy for the beta emission, in keV keV
max
Volume of laboratory sample, in litre l
Mass of laboratory sample, in kilogram kg
Density of the sample, in kilogram per litre kg l
c Activity concentration, in becquerel per litre Bq l
Activity per unit of mass, in becquerel per kilogram Bq kg
A Activity of the calibration source, in becquerel Bq
n Number of counting -
t Background counting time, in second s
t Sample counting time, in second s
t Calibration counting time, in second s
r Background count rate, per second s
r Test sample count rate, per second s
r Calibration count rate, per second s
Detection efficiency -
f Quench factor -
ε Chemical recovery -
m Mass of total carbon in the sample, in kilogram kg
m Mass of carbon in the precipitate, in kilogram kg
m Mass of carbon in the carrier, in kilogram kg
m Mass of sample carbon in the precipitate, in kilogram kg

Standard uncertainty associated with the measurement result; in becquerel per litre Bq l

uc()
Bq l

U Expanded uncertainty, calculated by Uk=⋅uc with k = 1, 2,…, in becquerel per litre

Decision threshold, in becquerel per litre Bq l
Detection limit, in becquerel per litre Bq l

Lower and upper limits of the probabilistically symmetric coverage interval, in bec- Bq l

C ,C
querel per litre

Lower and upper limits of the shortest coverage interval, in becquerel per litre Bq l

cc,
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4 Principle

The method described is for measurement of C in water samples by direct liquid scintillation counting.

The general principles of this method are described in ISO 19361.

This direct determination is applicable to the analysis of water samples that can produce a homogeneous

mixture between the test portion and a suitable scintillation cocktail.

The direct LSC method does not apply to waters containing micelles or large organic molecules (e.g.

lipids, fulvic acid, humic acid, etc.) that do not form homogeneous mixtures with scintillation cocktails.

In these cases, there is a risk that the beta radiation is attenuated by the micelles. This will reduce

the counting efficiency of the system and hence the results may be underestimated. For these samples,

the determination of C requires additional chemical processing (such as chemical oxidation or

combustion). Examples of methods of chemical preparation are described in Annexes C and D.

The choice of the analytical procedure (either with or without chemical preparation of the water sample

[17] [18]

prior to determination), depends on the aim of the measurement and the sample characteristics

[19] [20]

A prerequisite for the direct determination of C in a water sample is the absence of, or a negligible

contribution from, other beta-emitting radionuclides, such as Sr and Ra isotopes. When the

radionuclide content of the sample is unknown, the method specified in this document only provides a

C equivalent activity for the sample.

To determine the background count rate, a blank sample is prepared in the same way as the test portion.

The blank sample is prepared using a reference water of the lowest activity available, also sometimes

called “dead water”.

To determine the detection efficiency, it is necessary to measure a water sample having a known C

activity under conditions that are identical to those used for the test sample. This water shall be a

dilution of this mixture produced with the reference water, or a water with a traceable C activity

usable without dilution.

Where chemical quenching may affect the measurement results, it is necessary to correct the counting

data using a quench curve (see 7.4).
5 Sampling and storage
5.1 Sampling

Conditions of sampling and handling shall conform to ISO 5667 part 1, 3 and 10. Guidance is given for

the different types of water in references [8] to[15].
2- -

The samples shall not be acidified to avoid the destruction of the carbonic equilibrium (CO , HCO ,

3 3

H CO ), as specified in ISO 5667-3. Basification of the sample is recommended, for example to between

2 3
pH 8 and 9.

It is important that the laboratory receives a representative sample, unmodified during transport or

storage and in an undamaged container. It is recommended that a glass container filled to the maximum

is used to minimize C exchange with atmospheric CO .

For low level activity measurements, it is important to minimize any contact between sample and

atmosphere during the sampling.
5.2 Sample storage

If required, the sample shall be stored in accordance with ISO 5667-3 for carbon dioxide. If the storage

duration exceeds that specified in ISO 5667-3, it is advisable to store the samples in glass containers.

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6 Reagents and equipment

During the analysis, unless otherwise stated, use only reagents of recognized analytical grade.

6.1 Reagents
6.1.1 Reference water for the blank

The reference water for the blank should be as free as possible of chemical or radioactive impurities,

although it may have a low C activity concentration, at the time the samples are measured.

For example, obtain water with a 14C activity concentration as low as possible, e.g. (deep)

subterranean water. Distill the water. Keep the distillate in a well-sealed borosilicate glass bottle in

the dark at a temperature as constant as possible; this reference water shall be kept physically remote

from any

14C-containing material (see next paragraph). Determine (see final paragraph) the 14C activity

concentration of this water, in becquerel per litre, and note the date of this determination.

It is advisable to keep an adequate quantity of reference water in stock and to draw off small working

volumes from it for immediate use, as required. Contamination with C (e.g. from CO in the air) or

other radioactive species should be avoided.

For measurement of activity concentrations close to 1 Bq l , water with a very low activity concentration

is necessary as reference water.
6.1.2 Calibration source solution

In order to avoid cross-contamination, prepare the calibration source solution in a suitable location

which is well removed from the area where the C analyses are to be carried out. Transfer a known

amount of C aqueous standard solution into a volumetric flask (e.g. of capacity 100 ml). Make up to

the mark with blank reference water and mix well. The calibration source solution must have sufficient

C activity such that, when used to prepare counting sources, a suitable count rate to reach the

required measurement uncertainty is obtained. Calculate the C activity concentration of the resulting

calibration source solution, in becquerel per litre. Note the date at which the standard solution was

made up, to monitor the ageing of the solution.

It is recommended to select the standard source container size so as to minimize the volume of air

above the solution and therefore minimize the exchange of C with the atmosphere at each opening of

the container.
6.1.3 Scintillation solution

The scintillation cocktail is chosen according to the characteristics of the test sample to be analysed

[21][22]
(e.g. precipitate or alkaline) and according to the properties of
...

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