ISO 4907-1:2023

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 4907-1
ISO/TC 61/SC 5
Plastics — Ion exchange resin —
Secretariat: DIN
Voting begins on:
Part 1:
2023-01-30
Determination of exchange capacity of
Voting terminates on:
acrylic anion exchange resins
2023-03-27
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 SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 4907-1:2023(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 1 ----------------------
ISO/FDIS 4907-1:2023(E)
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 4907-1
ISO/TC 61/SC 5
Plastics — Ion exchange resin —
Secretariat: DIN
Voting begins on:
Part 1:
Determination of exchange capacity of
Voting terminates on:
acrylic anion exchange resins
COPYRIGHT PROTECTED DOCUMENT
© ISO 2023
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.
RECIPIENTS OF THIS DRAFT ARE INVITED TO
ISO copyright office
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
CP 401 • Ch. de Blandonnet 8
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
CH-1214 Vernier, Geneva
DOCUMENTATION.
Phone: +41 22 749 01 11
IN ADDITION TO THEIR EVALUATION AS
Reference number
Email: copyright@iso.org
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO-
ISO/FDIS 4907-1:2023(E)
Website: www.iso.org
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
Published in Switzerland
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN-
DARDS TO WHICH REFERENCE MAY BE MADE IN
ii
  © ISO 2023 – All rights reserved
NATIONAL REGULATIONS. © ISO 2023

---------------------- Page: 2 ----------------------
ISO/FDIS 4907-1:2023(E)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Apparatus . 6
7 Samples . 7
7.1 Sampling . 7
7.2 Sample preparation . 7
8 Procedure .8
8.1 Removal of the external water . 8
8.2 Water content . 8
8.3 Strong-base group capacity . 8
8.4 Weak-base group capacity . 8
8.5 Weak-acid group capacity. 8
9 Calculation . 9
9.1 Strong-base group capacity . 9
9.2 Weak-base group capacity . 9
9.3 Weak-acid group capacity. 10
10 Test report .11
Annex A (normative) Sampling .12
Annex B (normative) Determination of water content of anion exchange resins by
centrifugation .14
Bibliography .16
iii
© ISO 2023 – All rights reserved

---------------------- Page: 3 ----------------------
ISO/FDIS 4907-1:2023(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 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
A list of all parts in the ISO 4907 series can be found on the ISO website.
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 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 4907-1:2023(E)
Introduction
Following the traditional chemical processes such as distillation and extraction, ion exchange and
adsorption technology has also become a typical chemical separation technology, which plays an
important role in efficient extraction, concentration and refining. Since the realization of organic
synthesis, ion exchange resin has become one of the key materials for exchange and adsorption. At
present, they have been widely used in water treatment, environmental protection, petrochemical
industry, food and medicine, hydrometallurgy and energy industry, almost involving the core content of
the United Nations Sustainable Development Goals (SDGs).
Ion exchange resin is a kind of high polymer organic copolymer, which is composed of insoluble three-
dimensional space network framework, functional groups connected to the framework and exchangeable
ions with opposite charges. The main features determined by the structure are exchangeable, selective,
adsorbable and catalytic. However, even the same resin has different properties in different forms,
such as exchange capacity and water content, so a unified method is needed to provide basis for
manufacturing, quality supervision, technical exchange, factory inspection and arbitration.
Because of the special structure, acrylic anion exchange resins contain not only strong-base and weak-
base groups, but also weak-acid groups, and the content of weak-acid groups directly affects the using
effect. This document specifies how to determine the exchange capacity of acrylic anion exchange
resins.
v
© ISO 2023 – All rights reserved

---------------------- Page: 5 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 4907-1:2023(E)
Plastics — Ion exchange resin —
Part 1:
Determination of exchange capacity of acrylic anion
exchange resins
1 Scope
This document specifies test methods of the strong-base group capacity, the weak-base group capacity
and the weak-acid group capacity of acrylic anion exchange resins.
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
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:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
standard form acrylic anion exchange resin
ionic type of the samples treated under the pretreatment and transformation conditions specified in
this document
3.2
strong-base group capacity
quantity of active groups in standard form acrylic anion exchange resin (3.1) that can exchange with
neutral salts under the conditions specified in this document
Note 1 to entry: It is expressed in millimoles of per gram or moles per litre (mol/l) of acrylic anion exchange
resins.
3.3
weak-base group capacity
quantity of active groups in standard form acrylic anion exchange resin (3.1) that can exchange with
acids under the conditions specified in this document
Note 1 to entry: It is expressed in millimoles of per gram or moles per litre (mol/l) of acrylic anion exchange
resins.
1
© ISO 2023 – All rights reserved

---------------------- Page: 6 ----------------------
ISO/FDIS 4907-1:2023(E)
3.4
weak-acid group capacity
quantity of active groups in standard form acrylic anion exchange resins (3.1) that can exchange with
alkali under the conditions specified in this document
Note 1 to entry: It is expressed in millimoles of per gram or in moles per litre (mol/l) of acrylic anion exchange
resins.
4 Principle
According to the definitions, strong-base group in acrylic anion exchange resins has the ability to split
neutral salts, while weak-base groups and weak-acid groups have not.
Calculate the strong-base group capacity by the exchanged chloride ion contents in titration, when the
standard form acrylic anion exchange resins react with neutral salts (such as sodium nitrate solution).
The reaction formula is:
CH NCHCl CH NCH NNO
() ()
 
23 23 3
3 3
 
 
RR− CH NCHH +→NaNO − CH NCHH +NaCl
() ()
 
23 2 3 23 2
 
CH COOH CH COOH
 
 2  2
Calculate the weak-base groups capacity by the unreacted acid contents in titration, when the standard
form acrylic anion exchange resins react with excessive monobasic acid solution (such as hydrochloric
acid).
The reaction formula is:
CH NCHCl CH NCHCl
() ()
 
2 3 2 3
3 3
 
 
RR− CH NCHH +→HClC− CH NCHH HCl
() ()
 
223 223
 
CH COOH CH COOH
 
 2  2
Calculate the weak-acid group capacity by the unreacted alkali and the exchanged chloride ion contents
in titration, when the standard form acrylic anion exchange resins react with excessive monobasic
solution (such as sodium hydroxide).
The reaction formula is:
CH NCHCl CH NCHOHH
() ()
 
2 3 2 3
3
3
 
 
RR− CH NC()HH +→NaOH − CH N(CH )H ++HO NaCl
 
223 223 2
 
CH COONa
CH COOH

 2
 2 
5 Reagents
WARNING — Reagents used in this document can have potential hazards to human health and
the environment. Ensure that the instructions for the use of reagents are strictly followed.
Unless otherwise indicated, the reagents specified in this document should be analytical grade.
Commercially available, ready-made solutions may be used.
5.1 Water, grade 2 in accordance with ISO 3696.
5.2 Sodium hydroxide, standard solution, c(NaOH) ≈ 0,10 mol/l.
Dissolve 4 g of sodium hydroxide to 1 000 ml with water. Calibrate this solution at least weekly as
follows.
2
  © ISO 2023 – All rights reserved

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ISO/FDIS 4907-1:2023(E)
5.2.1 Calibration
Dry 10 g of potassium hydrogen phthalate (KHC H O , Guaranteed Reagent) at 105 °C to 110 °C for 4 h.
8 4 4
And then cool to room temperature in a desiccator.
Weigh 0,75 g of potassium hydrogen phthalate (m ) to the nearest 0,001 g, and dissolve with 100 ml
1
of water in a flask. Add 0,1 ml of phenolphthalein indicator solution. Titrate with 0,10 mol/l sodium
hydroxide solution (5.2) until the pink colour appears and persists for 15 s. Record the consumption
volume of alkali (V ).
1
5.2.2 Blank determination
Pipet 100 ml of water. Carry out a blank determination according to the procedure 5.2.1. Record the
consumption volume of alkali (V ).
2
5.2.3 Calculation
See Formula (1):
1 000×m
1
c()NaOH = (1)
204,(220× VV- )
12
where
is the actual concentration, expressed in moles per litre (mol/l), of the sodium hydroxid
c(NaOH)
solution;
m is the mass, expressed in grams (g), of potassium hydrogen phthalate;
1
is the titration consumption volume, expressed in millilitres (ml), of the sodium hydroxide
V
1
solution;
is the blank consumption volume, expressed in millilitres (ml), of the sodium hydroxide
V
2
solution.
5.3 Hydrochloric acid, standard solution, c(HCl) ≈ 0,10 mol/l.
Dilute 9 ml of hydrochloric acid (1,19 g/ml) to 1 000 ml with water. Calibrate this solution at least
weekly as follows.
5.3.1 Calibration
Dry 5 g of sodium carbonate (Na CO , Guaranteed Reagent) at 270 °C to 300 °C for 4 h. And then cool to
2 3
room temperature in a desiccator.
Weigh 0,2 g of sodium carbonate (m ) to the nearest 0,001 g, and dissolve with 100 ml water in a flask.
2
Add 0,1 ml of bromocresol green-methyl red indicator solution. Titrate with 0,1 mol/l hydrochloric acid
solution (5.3) until the greenish-blue colour disappears. Record the consumption volume of acid (V ).
3
5.3.2 Blank determination
Pipet 100 ml of water. Carry out a blank determination according to the appropriate procedure 5.3.1.
Record the consumption volume of acid (V ).
4
3
© ISO 2023 – All rights reserved

---------------------- Page: 8 ----------------------
ISO/FDIS 4907-1:2023(E)
5.3.3 Calculation
See Formula (2):
1 000×m
2
c()HCl = (2)
52,(994× VV- )
34
where
is the actual concentration, expressed in moles per litre (mol/l), of the hydrochloric acid
c(HCl)
solution;
m is the mass, expressed in grams (g), expressed of sodium carbonate;
2
is the titration consumption volume, expressed in millilitres (ml), of hydrochloric acid
V
3
solution;
V is the blank consumption volume, expressed in millilitres (ml), of hydrochloric acid solution.
4
5.4 Silver nitrate, standard solution, c(AgNO ) ≈ 0,10 mol/l.
3
Dissolve 17,5 g of silver nitrate to 1 000 ml with water. Store in an amber glass bottle. Calibrate this
solution at least weekly as follows.
5.4.1 Calibration
Dry 5 g of sodium chloride (NaCl, Guaranteed Reagent) at 500 °C for 10 min. And then cool to room
temperature in a desiccator.
Weigh 1,649 g of sodium chloride (m ) to the nearest 0,001 g, and dissolve to 1 000 ml with water.
3
...

ISO/FDIS 4907-1:20222023(E)
ISO TC 61/SC 5/WG 11
Date: 2022-112023-01-13
Secretariat: DIN
Plastics — Ion exchange resin — Part 1: Determination of exchange capacity of acrylic anion
exchange resins

---------------------- Page: 1 ----------------------
ISO/FDIS 4907-1:2023(E)
© ISO 20222023
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 2023 – All rights reserved

---------------------- Page: 2 ----------------------
ISO/FDIS 4907-1:2023(E)
Contents
Foreword . v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Reagents . 2
6 Apparatus . 5
7 Samples . 7
7.1 Sampling . 7
7.2 Sample preparation . 7
8 Procedure . 8
8.1 Removal of the external water . 8
8.2 Water content . 8
8.3 Strong-base group capacity . 8
8.4 Weak-base group capacity . 8
8.5 Weak-acid group capacity . 8
9 Calculation . 9
9.1 Strong-base group capacity . 9
9.2 Weak-base group capacity . 9
9.3 Weak-acid group capacity . 10
10 Test Report . 10
Annex A (normative) Sampling . 12
Annex B (normative) Determination of water content of anion exchange resins by
centrifugation . 14

© ISO 2023 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO/FDIS 4907-1:2023(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 61, Plastics, Subcommittee SC 5, Physical-
chemical properties.
A list of all parts in the ISO 4907 series can be found on the ISO website.
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 2023 – All rights reserved

---------------------- Page: 4 ----------------------
ISO/FDIS 4907-1:2023(E)
Introduction
Following the traditional chemical processes such as distillation and extraction, ion exchange and
adsorption technology has also become a typical chemical separation technology, which plays an
important role in efficient extraction, concentration and refining. Since the realization of organic
synthesis, ion exchange resin has become one of the key materials for exchange and adsorption. At
present, they have been widely used in water treatment, environmental protection, petrochemical
industry, food and medicine, hydrometallurgy and energy industry, almost involving the core content of
the United Nations Sustainable Development Goals (SDGs).
Ion exchange resin is a kind of high polymer organic copolymer, which is composed of insoluble three-
dimensional space network framework, functional groups connected to the framework and
exchangeable ions with opposite charges. The main features determined by the structure are
exchangeable, selective, adsorbable and catalytic. However, even the same resin has different properties
in different forms, such as exchange capacity and water content, so a unified method is needed to
provide basis for manufacturing, quality supervision, technical exchange, factory inspection and
arbitration.
Because of the special structure, acrylic anion exchange resins contain not only strong-base and weak-
base groups, but also weak-acid groups, and the content of weak-acid groups directly affects the using
effect. This document specifies how to determine the exchange capacity of acrylic anion exchange
resins.
© ISO 2023 – All rights reserved v

---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO/FDIS 4907-1:2023(E)

Plastics — Ion exchange resin — Part 1: Determination of
exchange capacity of acrylic anion exchange resins
1 Scope
This document specifies test methods of the strong-base group capacity, the weak-base group capacity
and the weak-acid group capacity of acrylic anion exchange resins.
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
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:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1
standard form acrylic anion exchange resin
ionic type of the samples treated under the pretreatment and transformation conditions specified in
this document
3.2
strong-base group capacity
quantity of active groups in standard form acrylic anion exchange resin (3.1) that can exchange with
neutral salts under the conditions specified in this document
Note 1 to entry: It is expressed in millimoles of per gram or moles per literlitre (mol/l) of acrylic anion
exchange resins.
3.3
weak-base group capacity
quantity of active groups in standard form acrylic anion exchange resin (3.1) that can exchange with
acids under the conditions specified in this document
Note 1 to entry: It is expressed in millimoles of per gram or moles per literlitre (mol/l) of acrylic anion
exchange resins.
3.4
weak-acid group capacity
quantity of active groups in standard form acrylic anion exchange resins (3.1) that can exchange with
alkali under the conditions specified in this document
© ISO 2023– All rights reserved 1

---------------------- Page: 6 ----------------------
ISO/FDIS 4907-1:2023(E)
Note 1 to entry: It is expressed in millimoles of per gram or in moles per literlitre (mol/l) of acrylic anion
exchange resins.
4 Principle
According to the definitions, strong-base group in acrylic anion exchange resins has the ability to split
neutral salts, while weak-base groups and weak-acid groups have not.
Calculate the strong-base group capacity by the exchanged chloride ion contents in titration, when the
standard form acrylic anion exchange resins react with neutral salts (such as sodium nitrate solution).
The reaction formula is:
CH N CH Cl CH N CH NO
( ) ( )

23 23 3
3 3


RR− CH N(CH )H + NaNO →− CH N(CH )H + NaCl

2 3 2 3 2 3 2

CH COOH CH COOH

2 2
CH N CH Cl CH N CH NO
( ) ( )

23 23 3
3 3


RR− CH N(CH )H + NaNO →− CH N(CH )H + NaCl

2 3 2 3 2 3 2

CH COOH CH COOH
2 2

Calculate the weak-base groups capacity by the unreacted acid contents in titration, when the standard
form acrylic anion exchange resins react with excessive monobasic acid solution (such as hydrochloric
acid).
The reaction formula is:
CH N CH Cl CH N CH Cl
( ) ( )

23 23
33


RR− CH N CH H + HCl→− CH N CH H HCl
( ) ( )

2 3 2 2 3 2

CH COOH CH COOH

22
CH N CH Cl CH N CH Cl
( ) ( )

23 23
33


RR− CH N(CH )H + HCl→− CH N(CH )H HCl

2 3 2 2 3 2

CH COOH CH COOH

22
Calculate the weak-acid group capacity by the unreacted alkali and the exchanged chloride ion contents
in titration, when the standard form acrylic anion exchange resins react with excessive monobasic
solution (such as sodium hydroxide).
The reaction formula is:
CH N CH Cl CH N CH OH
( ) ( )
 
23 23
3 3
 

RR− CH N CH H + NaOH→− CH N(CH )H + H O+ NaCl
( )

2 3 2 2 3 2 2

CH COOH CH COONa
 
 2  2
2 © ISO 2023 – All rights reserved

---------------------- Page: 7 ----------------------
ISO/FDIS 4907-1:2023(E)
CH N CH Cl CH N CH OH
( ) ( )
 
23 23
3 3
 

RR− CH N CH H + NaOH→− CH N(CH )H + H O+ NaCl
( )

2 3 2 2 3 2 2

CH COONa
CH COOH
 
 2  2
5 Reagents
WARNING — Reagents used in this document maycan have potential hazards to human health and the
environment. Please strictly followEnsure that the instructions for the use of reagents are strictly
followed.
Unless otherwise indicated, the reagents specified in this document should be analytical grade.
Commercially available, ready-made solutions may be used.
5.1 Water, grade 2 in accordance with ISO 3696.
5.2 Sodium hydroxide, standard solution, c(NaOH) ≈ 0,10 mol/l.
Dissolve 4 g of sodium hydroxide to 1 000 ml with water. Calibrate this solution at least weekly as
follows.
5.2.1 Calibration
Dry 10 g of potassium hydrogen phthalate (KHC H O , Guaranteed Reagent) at 105 °C to 110 °C for
8 4 4
4 h. And then cool to room temperature in a desiccator.
Weigh 0,75 g of potassium hydrogen phthalate (m ) to the nearest 0,001 g, and dissolve with 100 ml of
1
water in a flask. Add 0,1 ml of phenolphthalein indicator solution. Titrate with 0,10 mol/l sodium
hydroxide solution (5.2) until the pink colour appears and persists for 15 s. Record the consumption
volume of alkali (V ).
1
5.2.2 Blank determination
Pipet 100 ml of water. Carry out a blank determination according to the procedure 5.2.1. Record the
consumption volume of alkali (V ).
2
5.2.3 Calculation
See Formula (1):
1 000×m 1 000×m
1 1
c(NaOH)= c(NaOH)= (1)
204,220×(VV- ) 204,220×(VV- )
12 12
where
is the actual concentration, expressed in moles per litre (mol/l), of the sodium hydroxid
 c(NaOH)
solution;
 m is the mass, expressed in grams (g), of potassium hydrogen phthalate;
1
is the titration consumption volume, expressed in millilitres (ml), of the sodium
 V
1
hydroxide solution;
is the blank consumption volume, expressed in millilitres (ml), of the sodium hydroxide
 V
2
solution.
© ISO 2023 – All rights reserved 3

---------------------- Page: 8 ----------------------
ISO/FDIS 4907-1:2023(E)
5.3 Hydrochloric acid, standard solution, c(HCl) ≈ 0,10 mol/l.
Dilute 9 ml of hydrochloric acid (1,19 g/ml) to 1 000 ml with water. Calibrate this solution at least
weekly as follows.
5.3.1 Calibration
Dry 5 g of sodium carbonate (Na CO , Guaranteed Reagent) at 270 °C to 300 °C for 4 h. And then cool to
2 3
room temperature in a desiccator.
Weigh 0,2 g of sodium carbonate (m ) to the nearest 0,001 g, and dissolve with 100 ml water in a flask.
2
Add 0,1 ml of bromocresol green-methyl red indicator solution. Titrate with 0,1 mol/l hydrochloric acid
solution (5.3) until the greenish-blue colour disappears. Record the consumption volume of acid (V ).
3
5.3.2 Blank determination
Pipet 100 ml of water. Carry out a blank determination according to the appropriate procedure 5.3.1.
Record the consumption volume of acid (V ).
4
5.3.3 Calculation
See Formula (2):
1 000×m 1 000×m
2 2
c(HCl)= c(HCl)= (2)
52,994×(VV- ) 52,994×(VV- )
34 34
where
is the actual concentration, expressed in moles per litre (mol/l), of the hydrochloric
 c(HCl)
acid solution;
 m is the mass, expressed in grams (g), expressed of sodium carbonate;
2
is the titration consumption volume, expressed in millilitres (ml), of hydrochloric acid
 V
3
solution;
is the blank consumption volume, expressed in millilitres (ml), of hydrochloric acid
 V
4
solution.
5.4 Silver nitrate, standard solution, c(AgNO ) ≈ 0,10 mol/l.
3
Dissolve 17,5 g of silver nitrate to 1 000 ml with water. Store in an amber glass bottle. Calibrate this
solution at least weekly as follows.
5.4.1 Calibration
Dry 5 g of sodium chloride (NaCl, Guaranteed Reagent) at 500 °C for 10 min. And then cool to room
temperature in a desiccator.
Weigh 1,649 g of sodium chloride (m ) to the nearest 0,001 g, and dissolve to 1 000 ml with water.
3
Pipet 10 ml of sodium chloride solution in a flask, and add 90 ml water and 1 ml of 10 % potassium
chromate indicator. Titrate with 0,1 mol/l silver nitrate standard solution (5.4) until the colorcolour
changes to brick-red and persists for 15 s. Record the consumption volume of the silver nitrate standard
solution (V ).
5
5.4.2 Blank determination
4 © ISO 2023 – All rights reserved

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ISO/FDIS 4907-1:2023(E)
Pipet 100 ml of water. Carry out a blank determination according to the appropriate procedure 5.4.1
and record the consumption volume of the silver nitrate standard solution (V ).
6
5.4.3 Calculation
See Formula (3):
1 000×m 1 000×m
3 3
c(AgNO )= c(AgNO )= (3)
3 3
58,442×(VV- ) 58,442×(VV- )
56 56
where
is the actual concentration, expressed in moles per litre (mol/l), of the silver nitrate
 c(AgNO )
3
standard solution;
 m is the mass, expressed in grams (g), of sodium chloride;
3
is the titration consumption volume, expressed in millilitres (ml), of the silver
 V
5
nitrate standard solution;
is the blank consumption volume, expressed in millilitres (ml), of the silver nitrate
 V
6
standard solution.
5.5 Sodium nitrate solution, c(NaNO ) = 1 mol/l.
3
Dissolve 85 g of sodium nitrate to 1 000 ml with water.
5.6 Sodium hydroxide solution, c(NaOH) = 1 mol/l.
...