SIST EN ISO 5667-3:2018

Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3:2018)

This document specifies general requirements for sampling, preservation, handling, transport and storage of all water samples including those for biological analyses.
It is not applicable to water samples intended for microbiological analyses as specified in ISO 19458, ecotoxicological assays, biological assays and passive sampling as specified in the scope of ISO 5667‑23.
This document is particularly appropriate when spot or composite samples cannot be analysed on site and have to be transported to a laboratory for analysis.

Wasserbeschaffenheit - Probenahme - Teil 3: Konservierung und Handhabung von Wasserproben (ISO 5667-3:2018)

Dieses Dokument legt allgemeine Anforderungen für die Probenahme, Konservierung, Handhabung, den Transport und die Lagerung aller Wasserproben einschließlich derer für biologische Untersuchungen fest.
Es ist nicht anwendbar für Wasserproben zur mikrobiologischen Untersuchung nach ISO 19458, für ökotoxikologische Tests, für biologische Tests sowie zur passiven Probenahme nach ISO 5667 23.
Dieses Dokument ist besonders für jene Proben (Einzel  oder Mischproben) geeignet, die nicht unmittelbar vor Ort untersucht werden können und hierfür in das Labor gebracht werden müssen.

Qualité de l'eau - Échantillonnage - Partie 3: Conservation et manipulation des échantillons d'eau (ISO 5667-3:2018)

Le présent document spécifie les exigences générales relatives à l'échantillonnage, la conservation, la manipulation, le transport et le stockage de tous les échantillons d'eau, y compris ceux destinés à des analyses biologiques.
Elle ne s'applique pas aux échantillons d'eau destinés à des analyses microbiologiques telles que spécifiées dans l'ISO 19458, des essais écotoxicologiques, des essais biologiques et ni à l'échantillonnage passif tel que spécifié dans le domaine d'application de l'ISO 5667‑23.
Le présent document s'applique en particulier chaque fois qu'un échantillon ponctuel ou composite ne peut être analysé sur site et doit être transporté vers un laboratoire pour analyse.

Kakovost vode - Vzorčenje - 3. del: Konzerviranje in ravnanje z vzorci vode (ISO 5667-3:2018)

Ta dokument določa splošne zahteve za vzorčenje, konzerviranje, ravnanje, prevoz in skladiščenje vseh vzorcev vode, tudi tistih za biološke analize.
Ne uporablja se za vzorce vode za mikrobiološke analize iz standarda ISO 19458 ter za ekotoksikološke preskuse, biološke preskuse in pasivno vzorčenje iz standarda ISO 5667-23.
Ta dokument je zlasti primeren, če naključnih ali sestavljenih vzorcev ni mogoče analizirati na mestu samem in jih je treba prenesti v laboratorij za analizo.

General Information

• Status: Withdrawn
• Public Enquiry End Date: 01-Apr-2018
• Publication Date: 20-Aug-2018
• Withdrawal Date: 15-Apr-2024
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: KAV - Water quality
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 16-Apr-2024
• Due Date: 09-May-2024
• Completion Date: 16-Apr-2024
• Directive: TRRTP074 - Pravilnik o spremembah in dopolnitvah Pravilnika o monitoringu stanja površinskih voda
• Ref Project: EN ISO 5667-3:2018 - Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3:2018)

Relations

• Replaces: SIST EN ISO 5667-3:2013 - Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3:2012)
• Effective Date: 01-Sep-2018
• Replaced By: SIST EN ISO 5667-3:2024 - Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3:2024)
• Effective Date: 01-May-2024

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2018
1DGRPHãþD
SIST EN ISO 5667-3:2013
.DNRYRVWYRGH9]RUþHQMHGHO.RQ]HUYLUDQMHLQUDYQDQMH]Y]RUFLYRGH,62

Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667
-3:2018)
Wasserbeschaffenheit - Probenahme - Teil 3: Konservierung und Handhabung von
Wasserproben (ISO 5667-3:2018)
Qualité de l'eau - Échantillonnage - Partie 3: Conservation et manipulation des
échantillons d'eau (ISO 5667-3:2018)
Ta slovenski standard je istoveten z: EN ISO 5667-3:2018
ICS:
13.060.45 Preiskava vode na splošno Examination of water in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 5667-3
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2018
EUROPÄISCHE NORM
ICS 13.060.45 Supersedes EN ISO 5667-3:2012
English Version
Water quality - Sampling - Part 3: Preservation and
handling of water samples (ISO 5667-3:2018)
Qualité de l'eau - Échantillonnage - Partie 3: Wasserbeschaffenheit - Probenahme - Teil 3:
Conservation et manipulation des échantillons d'eau Konservierung und Handhabung von Wasserproben
(ISO 5667-3:2018) (ISO 5667-3:2018)
This European Standard was approved by CEN on 9 June 2018.

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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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
© 2018 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 5667-3:2018 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 5667-3:2018) 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 2018, and conflicting national standards
shall be withdrawn at the latest by December 2018.
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 5667-3:2012.
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, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 5667-3:2018 has been approved by CEN as EN ISO 5667-3:2018 without any
modification.
INTERNATIONAL ISO
STANDARD 5667-3
Fifth edition
2018-05
Water quality — Sampling —
Part 3:
Preservation and handling of water
samples
Qualité de l'eau — Échantillonnage —
Partie 3: Conservation et manipulation des échantillons d'eau
Reference number
ISO 5667-3:2018(E)
©
ISO 2018
ISO 5667-3:2018(E)
© ISO 2018
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: [phone]
Fax: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Sampling and chain of custody . 2
5 Reagents and materials . 2
6 Containers . 5
6.1 Container selection and preparation . 5
6.2 Filtration on site . 5
6.3 Filling the container . 5
7 Sample handling and preservation . 5
7.1 Sample handling and preservation for physical and chemical examination . 5
7.2 Sample handling and preservation for biological examination . 6
7.3 Sample handling and preservation for radiochemical analysis . 7
8 Sample transport . 7
9 Identification of samples . 8
10 Sample reception . 8
11 Sample storage . 8
Annex A (informative) Techniques for sample preservation .10
Annex B (informative) Container preparation .44
Annex C (informative) Protocol as used in Dutch validation studies .45
Bibliography .47
ISO 5667-3:2018(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 6,
Sampling (general methods).
This fifth edition cancels and replaces the fourth edition (ISO 5667-3:2012), of which it constitutes a
minor revision. The changes compared to the previous edition are as follows:
— updated references in Table A.1;
— clarification in the Introduction concerning use of the preservation times and conditions set out in
Table A.1.
A list of all parts in the ISO 5667 series can be found on the ISO website.
iv © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
Introduction
This document is intended to be used in conjunction with ISO 5667-1, which deals with the design of
sampling programmes and sampling techniques.
Where possible this document has been brought into line with current standards. Where new research
or validation results have provided new insights, the latest knowledge has been used.
Guidance on validation protocols can be found in ISO 17034.
ISO 5667-3 provides in Table A.1 validated preservation times and/or conditions as well as descriptions
of best practice. Table A.1 also refers, for each analyte, to those ISO standards available at the date of
publication of this ISO 5667-3. This is however not an exhaustive list. Other methods may be used when
they have been validated. However, it is strongly recommended that where a method validation is not
available, the preservation times for the analyte as listed in Table A.1 for ISO test methods be followed.
The preservation and storage conditions and maximum storage times per analyte as listed in Table A.1
should be regarded as default conditions to be applied in the absence of any other information.
However, if validation of preservation techniques and holding times has been carried out, relative
to specific circumstances and matrices, by a laboratory, then, provided that it can produce evidence
of this validation where they differ from those set out in Table A.1 of this standard, these validated
preservation and storage conditions and maximum storage times are deemed acceptable for use by the
validating laboratories.
Attention is drawn to the proposed development of a new part in the ISO 5667 series, which further
elaborates on ISO 5667-3:2018, Annex C, and which will contain guidelines and the elaboration of the
required techniques of how to validate new storage times or preservative methods and details of the
techniques described.
INTERNATIONAL STANDARD ISO 5667-3:2018(E)
Water quality — Sampling —
Part 3:
Preservation and handling of water samples
NOTICE — This document and the analytical International Standards listed in Annex A are
complementary. Where no analytical International Standard is applicable, the technique(s)
described in Tables A.1 to A.3 take(s) normative status.
When new or revised analytical standards are developed with storage times or preservative
techniques differing from those in Tables A.1 to A.3, then the storage times or preservative
techniques should be validated and presented to ISO/TC 147/SC 6/WG 3 for incorporation into
the next revision of this document.
1 Scope
This document specifies general requirements for sampling, preservation, handling, transport and
storage of all water samples including those for biological analyses.
It is not applicable to water samples intended for microbiological analyses as specified in ISO 19458,
ecotoxicological assays, biological assays and passive sampling as specified in the scope of ISO 5667-23.
This document is particularly appropriate when spot or composite samples cannot be analysed on site
and have to be transported to a laboratory for analysis.
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 3696, Water for analytical laboratory use — Specification and test methods
ISO 5667 (all parts), Water quality — Sampling
ISO 19458, Water quality — Sampling for microbiological analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions 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
3.1
integrity
property that the parameter(s) of interest, information or content of the sample container has not been
altered or lost in an unauthorized manner or subject to loss of representativeness
ISO 5667-3:2018(E)
3.2
sample preservation
any procedure used to stabilize a sample in such a way that the properties under examination are
maintained stable from the collection step until preparation for analysis
Note 1 to entry: Different analytes may require several samples from the same source that are stabilized by
different procedures.
[SOURCE: ISO 11074:2015, 4.4.20, modified — Note 1 to entry has been added.]
3.3
sample storage
process, and the result of keeping a sample available under predefined conditions, usually for a specified
time interval between collection and further treatment of a sample
Note 1 to entry: Specified time is the maximum time interval.
[SOURCE: ISO 11074:2015, 4.4.22, modified — Note 1 to entry has been added; “soil sample” has been
changed to “sample”.]
3.4
storage time
period of time between filling of the sample container and further treatment of the sample in the
laboratory, if stored under predefined conditions
Note 1 to entry: Sampling finishes as soon as the sample container has been filled with the sample. Storage time
ends when the sample is taken by the analyst to start sample preparation prior to analysis.
Note 2 to entry: Further treatment is, for most analytes, a solvent extraction or acid destruction. The initial steps
of sample preparation can be steps complementary to the storage conditions for the maintenance of analyte
concentrations.
4 Sampling and chain of custody
If there is a need to take samples, this is done according to a sampling programme. The first step is to
design a sampling programme. Guidance on this topic is given in ISO 5667-1.
Depending on the sample type and matrix, the guidelines found in ISO 19458 and in the relevant part(s)
of ISO 5667 shall be consulted.
The process of preservation and handling of water samples consists of several steps. During this
process, the responsibility for the samples might change. To ensure the integrity of the samples, all
steps involving the sample shall be documented.
All preparation procedures shall be checked to ensure positive or negative interferences do not occur.
As a minimum, this shall include the analysis of blanks (e.g. field blank or sample container) or samples
containing known levels of relevant analytes as specified in ISO 5667-14.
5 Reagents and materials
WARNING — Certain preservatives (e.g. acids, alkalis, formaldehyde) need to be used with
caution. Sampling personnel should be warned of potential dangers, and appropriate safety
procedures should be followed.
The following reagents are used for the sample preservation and shall only be prepared according
to individual sampling requirements. All reagents used shall be of at least analytical reagent grade
and water shall be of at least ISO 3696, grade 2. Acids referred to in this document are commercially
available “concentrated” acids.
2 © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
All reagents shall be labelled with a “shelf-life”. The shelf-life represents the period for which the
reagent is suitable for use, if stored correctly. This shelf-life shall not be exceeded. Any reagents that are
not completely used by the expiry of the shelf-life date shall be discarded.
NOTE Often the shelf-life of reagents is supplied by the receiving laboratory.
Check reagents periodically, e.g. by field blanks, and discard any reagent found to be unsuitable.
Between on-site visits, reagents shall be stored separately from sample containers and other equipment
in a clean, secure cabinet in order to prevent contamination.
Each sample shall be labelled accordingly, after the addition of the preservative. Otherwise, there could
be no visible indication as to which samples have been preserved, and which have not.
5.1 Solids.
5.1.1 Sodium thiosulfate pentahydrate, Na S O ·5H O, w(Na S O ·5H O) > 99 %.
2 2 3 2 2 2 3 2
5.1.2 Ascorbic acid, C H O , w(C H O ) > 99 %.
6 8 6 6 8 6
5.1.3 Sodium hydroxide, NaOH, w(NaOH) > 99 %.
5.1.4 Sodium tetraborate decahydrate, Na B O ·10H O, w(Na B O ·10H O), > 99 %.
2 4 7 2 2 4 7 2
CAUTION — Sodium tetraborate decahydrate is known to be a carcinogen, mutagen and
reproductive toxin (CMR).
5.1.5 Hexamethylenetetramine (hexamine, urotropine), C H N , w(C H N ) > 99 %.
6 12 4 6 12 4
5.1.6 Potassium iodide, KI, w(KI) > 99 %.
5.1.7 Iodine, I w(I ) > 99 %.
2, 2
5.1.8 Sodium acetate, C H NaO , w(C H NaO ) > 99 %.
2 3 2 2 3 2
5.1.9 Ethylenediamine, C H N , w(C H N ) > 99 %.
2 8 2 2 8 2
5.2 Solutions.
5.2.1 Zinc acetate solution C H O Zn (10 g/l).
4 6 4
Dissolve 10,0 g of zinc acetate in ∼100 ml of water . Dilute to 100 ml with water. Store the solution in a
polypropylene or glass bottle for a maximum period of 1 a.
5.2.2 Orthophosphoric acid (ρ ≈ 1,7 g/ml), H PO , w(H PO ) > 85 %, c(H PO ) = 15 mol/l.
3 4 3 4 3 4
5.2.3 Hydrochloric acid (ρ ≈ 1,2 g/ml), HCl, w(HCl) > 36 %, c(HCl) = 12,0 mol/l.
5.2.4 Nitric acid (ρ ≈ 1,42 g/ml), HNO , w(HNO ) > 65 %, c(HNO ) = 15,8 mol/l.
3 3 3
5.2.5 Sulfuric acid (ρ ≈ 1,84 g/ml), H SO (freshly prepared).
2 4
Dilute concentrated sulfuric acid (H SO ), ρ ≈ 1,84 g/ml, w(H SO ) ≈ 98 % 1 + 1 by carefully adding the
2 4 2 4
concentrated acid to an equal volume of water and mix.
ISO 5667-3:2018(E)
WARNING — Adding the concentrated acid to the water can give violent reactions because of an
exothermic reaction.
5.2.6 Sodium hydroxide solution (ρ ≈ 0,40 g/ml), NaOH.
5.2.7 Formaldehyde solution (formalin), CH O, φ(CH O) = 37 % to 40 % (freshly prepared).
2 2
WARNING — Beware of formaldehyde vapours. Do not store large numbers of samples in small
work areas.
5.2.8 Disodium salt of ethylenediaminetetraacetic acid (EDTA) (ρ ≈ 0,025 g/ml),
C H N Na O ⋅2H O, w(C H N Na O ⋅2H O) > 99 %.
10 14 2 2 8 2 10 14 2 2 8 2
Dissolve 25 g EDTA in 1 000 ml of water.
5.2.9 Ethanol C H OH, φ(C H OH) = 96 %.
2 5 2 5
5.2.10 Alkaline Lugol’s solution, 100 g potassium iodide (5.1.6), 50 g iodine (5.1.7), and 250 g sodium
acetate (5.1.8) in 1 000 ml water to pH 10.
5.2.11 Acidic Lugol’s solution, 100 g potassium iodide (5.1.6), 50 g iodine (5.1.7) and 100 ml glacial
acetic acid (5.2.17) in 1 000 ml water to pH 2.
5.2.12 Neutralized formaldehyde solution, formaldehyde solution (5.2.7) neutralized with sodium
tetraborate (5.1.4) or hexamethylenetetramine (5.1.5). Formalin solution at 100 g/l gives a final solution
of φ(CH O) = 3,7 % to 4,0 %.
WARNING — Beware of formaldehyde vapours. Do not store large numbers of samples in small
work areas.
5.2.13 Ethanol preservative solution.
Ethanol (5.2.9), formaldehyde solution (5.2.7) and glycerol (5.2.18) (100 + 2 + 1 parts by volume,
respectively).
5.2.14 Sodium hypochlorite NaOCl, w(NaOCl) = 10 %. Dissolve 100 g sodium hypochlorite (NaOCl) in
1 000 ml of water.
5.2.15 Potassium iodate KIO , w(KIO ) = 10 %. Dissolve 100 g potassium iodate (KIO ) in 1 000 ml
3 3 3
of water.
5.2.16 Methanoic acid (formic acid) CH O , φ(CH O ) > 98 %.
2 2 2 2
5.2.17 Glacial acetic acid C H O , w(C H O ) > 99 %.
2 4 2 2 4 2
5.2.18 Glycerol (glycerin, glycerine) C H (OH) .
3 5 3
5.3 Materials.
5.3.1 Container and cap, types as specified in Tables A.1 to A.3.
5.3.2 Filter, pore size 0,40 µm to 0,45 µm, unless a different filter size is specified in the analytical
International Standard.
4 © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
6 Containers
6.1 Container selection and preparation
The choice of sample container (5.3.1) is of major importance and ISO 5667-1 provides some guidance
on this subject.
Details of the type of container used for the collection and storage of samples are given in Tables A.1
to A.3. The same considerations given to this selection of suitable container material shall also be given
to the selection of cap liner materials.
Sample containers shall be made of a material appropriate for preserving the natural properties of both
the sample and the expected range of contaminants. Suitable types of containers for each analyte to be
measured are given in Tables A.1 to A.3.
NOTE For very low concentrations of metals, containers prescribed can be different from those used for
higher concentrations. Details can be found in Table A.1 or in the analytical International Standards.
If the samples are to be frozen, suitable containers, such as polyethylene (PE) or polytetrafluoroethylene
(PTFE), shall be used to prevent breakage.
The use of disposables is preferred. Some manufacturers supply containers with a certificate of
cleanliness. If such a certificate of cleanliness is supplied, it is not necessary to clean or rinse the
containers before use.
6.2 Filtration on site
Filtration on site is required in some cases.
— Groundwaters shall be filtered on site if dissolved metals need to be analysed.
— Waters shall be filtered (5.3.2) on site, if this is required according to Annex A. Unless specified
otherwise, a filter pore size 0,40 µm to 0,45 µm shall be used.
If immediate filtration on site is impossible, then the reason and the time between sampling and
filtration shall be added to the test report.
6.3 Filling the container
The container (5.3.1) shall be filled completely unless prescribed differently in Tables A.1 to A.3 or the
analytical International Standard used. If the samples are to be frozen as part of their preservation,
sample containers shall not be completely filled. This is in order to prevent breakage which may arise
from expansion of ice during the freezing and thawing process.
If no preservatives are present in the bottle, then prerinsing the bottle may be advisable. Guidance on
prerinsing can be found in ISO 5667-14.
7 Sample handling and preservation
7.1 Sample handling and preservation for physical and chemical examination
Waters, particularly fresh waters, waste waters and groundwaters, are susceptible to changes
as a result of physical, chemical or biological reactions which may take place between the time of
sampling and the commencement of analysis. The nature and rate of these reactions are often such
that, if precautions are not taken during sampling, transport and storage (for specific analytes), the
concentrations determined are different to those existing at the time of sampling.
The extent of these changes is dependent on the chemical and biological nature of the sample, its
temperature, its exposure to light, the type of the container in which it is placed, the time between
ISO 5667-3:2018(E)
sampling and analysis, and the conditions to which it is subjected, e.g. agitation during transport.
Further specific causes of variation are listed in a) to f).
a) The presence of bacteria, algae and other organisms can consume certain constituents of
the samples. These organisms can also modify the nature of the constituents to produce new
constituents. This biological activity affects, for example, the concentrations of dissolved oxygen,
carbon dioxide, compounds of nitrogen, phosphorus and, sometimes, silicon.
b) Certain compounds can be oxidized either by dissolved oxygen present in the samples, or by
atmospheric oxygen [e.g. organic compounds, Fe(II) and sulfides].
c) Certain substances can precipitate out of solution, e.g. calcium carbonate, metals, and metallic
compounds such as Al(OH) , or can be lost to the vapour phase (e.g. oxygen, cyanides, and mercury).
d) Absorption of carbon dioxide from air can modify pH, conductivity, and the concentration of
dissolved carbon dioxide. Passage of compounds like ammonia and silicon fluoride through some
types of plastics may also affect pH or conductivity.
e) Dissolved metals or metals in a colloidal state, as well as certain organic compounds, can be
irreversibly adsorbed on to the surface of the containers or solid materials in the samples.
f) Polymerized products can depolymerize, and conversely, simple compounds can polymerize.
Changes to particular constituents vary both in degree and rate, not only as a function of the type of
water, but also, for the same water type, as a function of seasonal conditions.
These changes are often sufficiently rapid to modify the sample considerably in a short time. In all
cases, it is essential to take precautions to minimize these reactions and, in the case of many analytes,
to analyse the sample with a minimum of delay. If the required precaution for changes is filtration on
site, then a filter (5.3.2) shall be used.
Details of the sample preservation are given in Table A.1.
7.2 Sample handling and preservation for biological examination
The handling of samples for biological examination is different from that for samples requiring
chemical analysis. The addition of chemicals to the sample for biological examination can be used for
either fixation and/or preservation of the sample. The term “fixation” is defined as the protection of
morphological structures, while the term “preservation” is defined as the protection of organic matter
from biochemical or chemical degradation. Preservatives, by definition, are toxic, and the addition of
preservatives may lead to the death of living organisms. Prior to death, irritation may cause the most
delicate organisms, which do not have strong cell walls, to collapse before fixation is complete. To
minimize this effect, it is important that the fixation agent enter the cell quickly.
IMPORTANT — Acidic Lugol’s solutions (5.2.11) can lead to the loss of structures in organisms
or also lead to the loss of small organisms (e.g. some flagellates); in this case, use an alkaline
Lugol’s solution (5.2.10), e.g. during the summer, when the appearance of silico-flagellates is
frequently observed.
The fixing and/or preservation of samples for biological examination shall meet the following criteria:
a) the effect of the fixative, and/or preservative, on the loss of the organism shall be known
beforehand;
b) the fixative or preservative shall effectively prevent the biological degradation of organic matter at
least during the storage period of the samples;
c) the fixative, and/or preservative, shall enable the biological analyte (e.g. organisms or taxonomical
groups) to be assessed during the storage period of the samples.
Details of the preservation of samples are given in Table A.2.
6 © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
7.3 Sample handling and preservation for radiochemical analysis
WARNING — Radioprotection such as shielding may be necessary, depending on the activity of
the sample.
There is little difference between the handling of samples for radiochemical analysis and the handling
of samples for physicochemical analysis.
The delay between sampling and measurement has to be consistent with the radioactive half-life of
the radionuclides of interest. The conditions to be taken for adequate storage are independent of the
radioactive half-life, but identical to those required for the corresponding stable isotope.
NOTE Cooling radiological samples is primarily used to prevent algal growth and biological spoilage. It is
not a necessary preservation step for radiochemical analyses. These samples are often combined with those for
physical, chemical or biological analysis.
8 Sample transport
Cooling or freezing procedures shall be applied to samples to increase the time period available for
transport and storage and if required by Tables A.1 to A.3. When transport takes place, the sampling
plan (e.g. ISO 5667-1) shall consider:
— the time between sampling and start of transport;
— transport time;
— starting time of analysis in the laboratory.
This sum of these three periods is limited to the maximum storage times according to Tables A.1 to A.3.
If the maximum storage time cannot be met, then the sampling plan shall be reformulated to allow
these requirements to be accommodated.
A cooling temperature of the device during transport of (5 ± 3) °C has been found suitable for many
applications. Cooling and freezing procedures applied shall be in line with instructions from the
analytical laboratory. Freezing especially requires detailed control of the freezing and thawing process
in order to return the sample to its initial equilibrium after thawing.
Containers holding samples shall be protected and sealed during transport in such a way that the
samples do not deteriorate or lose any part of their content. Container packaging shall protect the
containers from possible external contamination, particularly near the opening, and should not itself
be a source of contamination.
Glass containers shall be protected from potential breakage during transport by appropriate packaging.
Samples shall be transported as soon as possible after sampling and with cooling if necessary according
to Tables A.1 to A.3.
Laboratory samples for dispatch or transport by third parties and preserved laboratory samples should
be sealed in such manner that the integrity of the sample can be maintained.
Samples required for (potential) regulatory investigations should be sealed to a level that meets the
requirements of the authorities or other organization(s) concerned with the transport of the sample.
During transportation samples shall be stored in a cooling device capable of maintaining a temperature
of (5 ± 3) °C. For proper evaluation of the conditions during transport, a device capable of recording the
(maximum) temperature of the air surrounding the sample may be used.
NOTE Devices capable of logging of the air temperature during the transportation are available, but their
use and adequate calibration can be costly.
ISO 5667-3:2018(E)
9 Identification of samples
Container labels should withstand wetting, drying and freezing without detaching or becoming
illegible. The labelling system shall be waterproof to allow use on site.
The exact information given in the sampling report and on the sample labels depends on the objectives
of the particular measurement programme. In all cases, an indelible label shall be secured to the sample
container.
For each sample, at least the following information shall be available.
— A unique identifier, traceable to
— date, time and location of sampling;
— sample number;
— description of sample;
— name of sampling personnel;
— details of sample preservation, or fixation used;
— details of sample storage used;
— any information regarding integrity and manipulation of the sample;
— any other information, as necessary.
— A unique identifier, traceable to sample date, location, and sample number shall appear on the label
of the sample container.
All other information is supplementary and should be detailed in the sample report.
10 Sample reception
All information regarding sample, handling and storage shall be included in a sampling report.
Laboratory staff shall receive and check information on sample preservation and sample transport
conditions.
In all cases, and especially when a “chain of custody” process needs to be established, the number of
sample containers received in the laboratory shall be verified against the number of sample containers
submitted.
11 Sample storage
The storage duration of the water samples within the laboratory is specific to the analyte(s) to be
analysed. Samples shall be stored no longer than the maximum storage period given in Tables A.1 to
A.3. The maximum storage time includes the time of transport to the laboratory (3.4).
The refrigeration conditions within the laboratory shall be (3 ± 2) °C. Where samples are frozen for
preservation, unless otherwise specified, the temperature shall be maintained below −18 °C. Exceptions
to these refrigeration conditions are listed in Tables A.1 to A.3.
When thawing frozen samples, it is recommended that each sample container be placed in a separate
secondary container to minimize the risk of liquid loss, should a split become apparent during the
thawing process or a rupture occur during initial freezing and storage. A mild impact can cause splitting
of some plastics at low temperatures.
8 © ISO 2018 – All rights reserved

ISO 5667-3:2018(E)
With respect to thawing, it is recommended that this be done under ambient conditions, unless specified
otherwise in Tables A.1 to A.3 or the analytical International Standard being used.
ISO 5667-3:2018(E)
Annex A
(informative)
Techniques for sample preservation
A.1 General
This document and the analytical International Standards listed in this annex are complementary. See
the Notice on page 1.
In some cases the alternative preservation techniques listed contradict each other. It is intended that
where an existing analytical International Standard is used, the preservation technique described in
that method applies. However, alternative preservation techniques given in this document can also be
appropriate. Where no preservation method is described in the analytical International Standard, or no
analytical International Standard is used, the technique(s) listed in this document shall be used.
A validation protocol used for validation studies can be found in Annex C. Reports and data regarding
validation are listed in the bibliography.
A.2 Abbreviations for plastics
FEP perfluoro(ethylene/propylene) PFA perfluoroalkoxy (polymer)
PE polyethylene PP polypropylene
PE-HD high density polyethylene PTFE polytetrafluoroethylene
PET polyethylene terephthalate PVC poly(vinyl chloride)
A.3 Physicochemical and chemical analysis
See Table A.1. The following general remarks should be noted in relation to use of Table A.1.
— A preservation time of 1 d means that if 24 h is exceeded, this should be stated in the report.
— The types of containers are identical to those in the analytical International Standards. In some
cases, the type of container in the standard is very specific, e.g. PTFE. This is essential when very
low concentrations have to be measured. In other cases, when the specific type of plastic is not
important, the term plastics is sufficient.
A.4 Biological analysis
The following general remarks should be noted in relation to use of Table A.2.
— Plastics used for containers in the laboratory are for instance PE, PTFE, PET, PP, PFA, and FEP.
— lf a preservation period is not specified, it is generally unimportant. The indication “1 month”
represents preservations without particular difficulty.
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ISO 5667-3:2018(E)
A.5 Radiochemical analytes and activities
The following general remarks should be noted in relation to use of Table A.3.
WARNING — Radioprotection such as shielding may be necessary, depending on the activity of
the sample.
— Acidification is carried out to avoid algal growth, biological spoilage, and adsorption of metal ions
to the inner wall of the sample container.
— Contamination of the sample should be avoided, especially if the sample activity is very low. Some
sample sites can have measurable activity in the soil or air, or in waters other than those being
sampled. Laboratories, as well as some items of domestic equipment, can contain radioactive
material. When sampling precipitation, any special requirements in this table are additional to
those given in ISO 5667-8. As the collection of sufficient sample can require a period of days, both
the starting and finishing times and dates should be recorded. A record of precipitation collection
for the sample station for the appropriate period should be appended. Stabilizer or carrier may be
added, if appropriate for the analytes being measured.
— Plastics used for containers in the laboratory are for instance PE, PTFE, PET, PP, PFA, and FEP.
NOTE Some plastics bottles slowly concentrate samples over a period of many months by being very slightly
permeable to water. Also see the comments for e.g. radon.
ISO 5667-3:2018(E)
12 © ISO 2018 – All rights reserved
Table A.1 — Techniques for sample preservation — Physicochemical and chemical analysis
Reference International Preservation and storage conditions Maximum Validated or
Analyte to be studied Type of container
Standard additional to Clauses 8 and 11 storage times Best practice
For samples high in dissolved gases, an-
alyse preferably on site. Reduction and
Plastics or glass
oxidation during storage can change
Acidity and alkalinity 14 d Best practice
the sample.
ISO 9963-1:1994 For samples high in dissolved gases,
PE, borosilicate glass
No reference to ISO 5667-3 analyse preferably on site.
Acidify to pH 1 to pH 2 with HNO
Plastics or glass
(5.2.4). Store samples in the dark or use
ISO 9562:2004 Glass is required if
dark-coloured bottles.
5 d Best practice
Adsorbable organic
No reference to ISO 5667-3 the concentration is
halides (AOX)
If samples are chlorinated, Note c
suspected to be low
applies.
Plastics Freeze to below –18 °C. 1 month Best practice
ISO 12010:2012
Alkanes, Naphthalene Short-
refers normatively to Glass Rinse bottles with 2 ml isooctane
chain
ISO 5667-3
polychlorinated
ISO 18635:2016 Glass Store samples in the dark or use
(SCCPs)
No reference to ISO 5667-3 dark-coloured bottles.
ISO 15586:2003 PE, PP, FEP
refers normatively to
ISO 5667-3
ISO 11885:2007 For normal
Acidify to pH 1 to pH 2 with HNO
refers normatively to concentrations:
Aluminium 1 month Best practice
(5.2.4).
ISO 5667-3 PE-HD, PTFE
ISO 17294-2:2016
For low
refers normatively to
concentrations:
ISO 5667-3
PFA, FEP
ISO 5667-3:2018(E)
Table A.1 (continued)
Reference International Preservation and storage conditions Maximum Validated or
Analyte to be studied Type of container
Standard additional to Clauses 8 and 11 storage times Best practice
Aluminium (continued) ISO 12020:1997 Suitable plastics, no
No reference to ISO 5667-3 polyolefins (may
contain traces of Al)
ISO 10566:1994 PE
refers normatively to
ISO 5667-3:1994
Plastics or glass Waters shall be filtered on site. Acidify 21 d Best practice
to pH 1 to pH 2 with H SO (5.2.5).
2 4
ISO 15923-1:2013
[82]
refers normatively Plastics or glass Waters shall be filtered on site. 1 d Validated
ISO 5667-3
ISO 7150-1:1984
No reference to ISO 5667-3
ISO 14911:1998
Ammonium
Waters shall be fil
...