prEN ISO 5667-3

Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO/DIS 5667-3:2023)

Wasserbeschaffenheit - Probenahme - Teil 3: Konservierung und Handhabung von Wasserproben (ISO/DIS 5667-3:2023)

Qualité de l'eau - Échantillonnage - Partie 3: Conservation et manipulation des échantillons d'eau (ISO/DIS 5667-3:2023)

Kakovost vode - Vzorčenje - 3. del: Konzerviranje in ravnanje z vzorci vode (ISO/DIS 5667-3:2023)

General Information

• Status: Not Published
• Publication Date: 04-Feb-2025
• ICS: 13.060.45 - Examination of water in general
• Technical Committee: CEN/TC 230 - Water analysis
• Drafting Committee: CEN/TC 230 - Water analysis
• Current Stage: 4020 - Submission to enquiry - Enquiry
• Start Date: 12-Jan-2023
• Completion Date: 12-Jan-2023
• Ref Project: oSIST prEN ISO 5667-3:2023 - Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO/DIS 5667-3:2023)

Relations

• Revises: EN ISO 5667-3:2018 - Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO 5667-3:2018)
• Effective Date: 18-Jan-2023

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO 5667-3:2023
01-marec-2023
Kakovost vode - Vzorčenje - 3. del: Konzerviranje in ravnanje z vzorci vode
(ISO/DIS 5667-3:2023)

Water quality - Sampling - Part 3: Preservation and handling of water samples (ISO/DIS

5667-3:2023)
Wasserbeschaffenheit - Probenahme - Teil 3: Konservierung und Handhabung von
Wasserproben (ISO/DIS 5667-3:2023)
Qualité de l'eau - Échantillonnage - Partie 3: Conservation et manipulation des
échantillons d'eau (ISO/DIS 5667-3:2023)
Ta slovenski standard je istoveten z: prEN ISO 5667-3
ICS:
13.060.45 Preiskava vode na splošno Examination of water in
general
oSIST prEN ISO 5667-3:2023 en,fr,de

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

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oSIST prEN ISO 5667-3:2023
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oSIST prEN ISO 5667-3:2023
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5667-3
ISO/TC 147/SC 6 Secretariat: BSI
Voting begins on: Voting terminates on:
2023-01-05 2023-03-30
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
ICS: 13.060.45
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
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NATIONAL REGULATIONS.
ISO/DIS 5667-3:2023(E)
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2023(E)
DRAFT INTERNATIONAL STANDARD
ISO/DIS 5667-3
ISO/TC 147/SC 6 Secretariat: BSI
Voting begins on: Voting terminates on:
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
ICS: 13.060.45
This document is circulated as received from the committee secretariat.
COPYRIGHT PROTECTED DOCUMENT
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© ISO 2023
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NATIONAL REGULATIONS.
Website: www.iso.org ISO/DIS 5667-3:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
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NOTIFICATION OF ANY RELEVANT PATENT
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)
Contents Page

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

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

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

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

3 Terms and definitions .................................................................................................................................................................................... 3

4 Sampling and chain of custody ............................................................................................................................................................. 3

5 Reagents and materials ................................................................................................................................................................................ 4

5.1 Solids ............................................................................................................................................................................................................... 4

5.2 Solutions ....................................................................................................................................................................................................... 5

5.3 Materials ...................................................................................................................................................................................................... 6

6 Containers ................................................................................................................................................................................................................... 6

6.1 Container selection and preparation .................................................................................................................................. 6

6.2 On-site filtration ........................................................................................................................................... ......................................... 6

6.3 Filling the container ........................................................................................................................................... ................................ 7

7 Sample handling and preservation .................................................................................................................................................. 7

7.1 Sample handling and preservation for physical and chemical analysis .............................................. 7

7.2 Sample handling and preservation for hydrobiological analysis .............................................................. 7

7.3 Sample handling and preservation for radiochemical analysis .................................................................. 8

8 Sample transport ................................................................................................................................................................................................. 8

9 Identification of samples .............................................................................................................................................................................9

10 Sample reception ..............................................................................................................................................................................................10

11 Sample storage ....................................................................................................................................................................................................10

Annex A (informative) Techniques for sample preservation .................................................................................................11

Annex B (informative) Container preparation ......................................................................................................................................62

Bibliography .............................................................................................................................................................................................................................63

iii
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(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 sixth edition cancels and replaces the fifth edition (ISO 5667-3:2018), which has been technically

revised.
The main changes compared to the previous edition are as follows:

— Addition of a reference to ISO/TS 5667-25 Water quality — Guideline on the validation of the storage

time of water samples;
— Addition of a flow diagram for preservation and storage of water samples;
— Updated references in Table A.1 and added references in Tables A.2 and A.3;
— Table A.1 has been splitted into an inorganic (A.1) and an organic (A.2) part;
— Addition of Table A.4 (Microbiological analysis);
— Addition of types of water to Tables A.1 to A.5;
— Explanation of the added terms used in Tables A.1 to A.5.
A list of all parts in the ISO 5667 series can be found on the ISO website.
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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.

[86]
Guidance on validation protocols can be found in ISO/TS 5667-25 and ISO 17034 .

ISO 5667-3 provides in Tables A.1 to A.5 where stated validated preservation times or conditions

according to ISO/TS 5667-25 or ISO 5667-3:2018, Annex C as well as descriptions of best practice.

Tables A.1 to A.5 also refer, for each analyte, to those analytical International Standards available at the

date of publication of this version of ISO 5667-3. This is however not an exhaustive list. Other preservation

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 Tables A.1 to A.5

for ISO test methods be followed. In case more than one storage time is provided in Tables A.1 to A.5 the

order of preferred use is:
— Validated;
— Provided by standard;
— Best practice.

The preservation and storage conditions and maximum storage times per analyte as listed in Tables A.1

to A.5 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 Tables A.1 to A.5 of this standard, these validated

preservation and storage conditions and maximum storage times are deemed acceptable for use by

the validating laboratories. If national standards contain information on preservation, these are to be

applied. This means that in these cases the contents of ISO 5667-3 are only to be considered informative.

Attention is drawn to the new part 25 in the ISO 5667 series, which further elaborates on

ISO 5667-3:2018, Annex C, and which contains guidelines and the elaboration of the required techniques

of how to validate new storage times or preservative methods and details of the techniques described.

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oSIST prEN ISO 5667-3:2023
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oSIST prEN ISO 5667-3:2023
DRAFT INTERNATIONAL STANDARD ISO/DIS 5667-3:2022(E)
Water quality — Sampling —
Part 3:
Preservation and handling of water samples
1 Scope

This document specifies general requirements for sampling, preservation, handling, transport

and storage of all water samples for physicochemical, chemical, hydrobiological and microbiological

analyses and radiochemical analytes and activities.

Guidance on the validation of storage times of water samples is provided in ISO/TS 5667-25.

It is not applicable to water samples intended for ecotoxicological assays, biological assays, passive

sampling as specified in the scope of ISO 5667-23 and microplastic particles and fibres.

This document is particularly appropriate when samples cannot be analysed on site and have to be

transported to a laboratory for analysis.

This document and the analytical International Standards can be used as presented in Figure 1.

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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)

WARNING — ‘Provided by standard’ and ‘validated’ could be based on previous standards and

methods and therefore not be in line with ISO/TS 5667-25. This information can be interpreted

by a qualified and experienced person.
Figure 1 — Flow diagram for preservation and storage of water samples
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.

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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)

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

applies.
ISO 5667 (all parts), Water quality — Sampling
ISO 19458:2007, 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 https:// 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

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 accordingly 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 the relevant part(s) of ISO 5667

and in ISO 19458 shall be consulted.
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)

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.
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 and waters used shall be of at least analytical grade.

Acids referred to in this document are commercially available "concentrated" acids.

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 1 Often the shelf-life of reagents is supplied by the receiving laboratory.

NOTE 2 For reagents that in the specific conditions are not likely to change during time, a periodically check

of the storage and packaging could be sufficient.

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 Sodium hydroxide, NaOH, w(NaOH) > 99 %.
5.1.3 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).
5.1.4 Hexamethylenetetramine (hexamine, urotropine), C H N , w(C H N ) > 99 %.
6 12 4 6 12 4
5.1.5 Potassium iodide, KI, w(KI) > 99 %.
5.1.6 Iodine, I w(I ) > 99 %.
2, 2
5.1.7 Sodium acetate, C H NaO , w(C H NaO ) > 99 %.
2 3 2 2 3 2
5.1.8 Ethylenediamine, C H N , w(C H N ) > 99 %.
2 8 2 2 8 2
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)
5.2 Solutions
5.2.1 Zinc acetate solution C H O Zn⋅2H O (100 g/l).
4 6 4 2

Dissolve 10,0 g of zinc acetate dihydrate in ∼90 ml of water. Dilute to 100 ml with water.

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 ≈ 1,43 g/ml), H SO , w(HNO ) ≈ 49 %, c(H SO ) ≈ 9 mol/l.
2 4 3 2 4

Dilute concentrated sulfuric acid (H SO ), ρ ≈ 1,84 g/ml, w(H SO ) ≈ 98 % 1 + 1 by carefully adding

2 4 2 4
the concentrated acid to an equal volume of water and mix.

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 % (freshly prepared).
2 2

WARNING — Beware of formaldehyde vapours. Do not store large numbers of samples in small

working 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 Acidic Lugol’s solution, 100 g potassium iodide (5.1.5), 50 g iodine (5.16) and 100 ml glacial

acetic acid (5.2.16) in 1 000 ml water to pH 2.

5.2.11 Alkaline Lugol’s solution, 100 g potassium iodide (5.1.5), 50 g iodine (5.1.6), and 250 g sodium

acetate (5.1.7) in 1 000 ml water to pH 10.

5.2.12 Neutralized formaldehyde solution, formaldehyde solution (5.2.7) neutralized with sodium

tetraborate (5.1.3) or hexamethylenetetramine (5.1.4). 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

working areas.
5.2.13 Ethanol preservative solution.

Ethanol (5.2.9), formaldehyde solution (5.2.7) and glycerol (5.2.17) (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.
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oSIST prEN ISO 5667-3:2023
ISO/DIS 5667-3:2022(E)

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 Glacial acetic acid C H O , w(C H O ) > 99 %.
2 4 2 2 4 2
5.2.17 Glycerol (glycerin, glycerine) C H (OH) .
3 5 3
5.2.18 Sodiumhydrogensulphate NaHSO .
5.3 Materials
5.3.1 Container and cap, types as specified in Tables A.1 to A.5.

5.3.2 Filter, membrane, pore size 0,40 µm to 0,45 µm, unless a different filter size is specified

in the analytical International Standard.
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.5. The same considerations given to this selection of suitable container material shall also be given

to the selection of cap liner materials. For microbiological analyses clean sterile bottles shall be used.

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.5.

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 On-site filtration
On-site filtration is required in some cases:

— If dissolved metals need to be analysed. Filter on site or as soon as possible after sampling.

Acidify to pH < 2 with HNO (5.2.4).

— If required according to Tables A.1 to A.5, e.g. ammonium, nitrate, nitrite, phosphate, sulfate

and silicates.

If immediate filtration on site is impossible where required, then the reason and the time between

sampling and filtration shall be added to the test report.
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6.3 Filling the container

Containers (5.3.1) should be filled as presecribed in Tables A.1 to A.5 or the analytical International

Standard. If there are no instructions regarding the filling of the containers, they should be filled

completely unless the samples are to be frozen as part of their preservation, the sample containers

shall not be filled completely. This is in order to prevent breakage which may arise from expansion of

the water sample during the freezing and thawing process.

If no preservatives are present in the bottle, 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 analysis

Waters, particularly surface waters, waste waters and groundwaters, are susceptible to changes

as a result of physical, chemical or hydrobiological 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

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 hydrobiological 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 (see Table A.1) 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. On-site filtration may be required as a precaution (6.2).

Details of the sample preservation are given in Tables A.1 and A.2.
7.2 Sample handling and preservation for hydrobiological analysi
...