ISO 17315:2014

Petroleum products and other liquids — Ethanol — Determination of total acidity by potentiometric titration

ISO 17315:2014 specifies a test method for the determination of total acidity of ethanol by potentiometric titration. The total acidity is reported as acetic acid mass, in milligrams, per ethanol volume, in litres, or as mass percent of acetic acid (% m/m), if the density of ethanol is known.

Produits pétroliers et autres liquides — Éthanol — Dosage de l'acidité totale par titration potentiométrique

General Information

• Status: Published
• Publication Date: 02-Oct-2014
• ICS: 75.160.20 - Liquid fuels
• ICS: 75.160.40 - Biofuels
• Technical Committee: ISO/TC 28/SC 7 - Liquid Biofuels
• Drafting Committee: ISO/TC 28/SC 7 - Liquid Biofuels
• Current Stage: 9092 - International Standard to be revised
• Completion Date: 08-Oct-2020

Relations

• Consolidated By: ISO 7438:2016 - Metallic materials — Bend test
• Effective Date: 06-Jun-2022

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 17315
First edition
2014-10-01
Petroleum products and other
liquids — Ethanol — Determination
of total acidity by potentiometric
titration
Produits pétroliers et autres liquides — Éthanol — Dosage de l’acidité
totale par titration potentiométrique
Reference number
ISO 17315:2014(E)
ISO 2014
---------------------- Page: 1 ----------------------
ISO 17315:2014(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2014

All rights reserved. Unless otherwise specified, 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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2014 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 17315:2014(E)
Contents Page

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

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

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

2 Terms and definitions ..................................................................................................................................................................................... 1

3 Reagents and materials ................................................................................................................................................................................. 1

4 Apparatus ..................................................................................................................................................................................................................... 3

5 Apparatus calibration ..................................................................................................................................................................................... 3

6 Procedure..................................................................................................................................................................................................................... 3

7 Calculation .................................................................................................................................................................................................................. 4

8 Expression of results ........................................................................................................................................................................................ 5

9 Precision ....................................................................................................................................................................................................................... 5

9.1 General ........................................................................................................................................................................................................... 5

9.2 Repeatability, r .........................................................................................................................................................................................5

9.3 Reproducibility, R ...................................................................................................................................................................................6

Bibliography ................................................................................................................................................................................................................................ 7

© ISO 2014 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 17315:2014(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 meaning of ISO specific terms and expressions related to conformity

assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers

to Trade (TBT) see the following URL: Foreword - Supplementary information

The committee responsible for this document is ISO/TC 28, Petroleum products and lubricants,

Subcommittee SC 7, Liquid biofuels.
iv © ISO 2014 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 17315:2014(E)
Introduction

Diluted hydrous solutions of organic acids, e.g. acetic acid, can corrode many materials. Thus, it is

necessary to determine and keep at low values the acid content in the final product.

An ethanol sample can have organic acids from the productive process, from its handling, contained in

additives, or due to sample degradation or contamination. The relative content of those components can

be determined by titration with a strong alkaline solution.

The numeric result of total acidity is a measure of the amount of acid components in the sample. Total

acidity is used as a quality control parameter of final product to prevent long-run corrosion problems.

For this reason, final product obtained from a blend of ethanol and other fuels has to have a limited

acidity.
© ISO 2014 – All rights reserved v
---------------------- Page: 5 ----------------------
INTERNATIONAL STANDARD ISO 17315:2014(E)
Petroleum products and other liquids — Ethanol —
Determination of total acidity by potentiometric titration

WARNING — The use of this International Standard can involve hazardous materials. This

International Standard does not purport to address all the safety problems associated with its

use. It is the responsibility of the user of this International Standard to establish appropriate

safety and health practices and determine the applicability of regulatory limitations prior to use.

1 Scope

This International Standard specifies a test method for the determination of total acidity of ethanol by

potentiometric titration. The total acidity is reported as acetic acid mass, in milligrams, per ethanol

volume, in litres, or as mass percent of acetic acid (% m/m), if the density of ethanol is known.

NOTE 1 For the purposes of this International Standard, the terms “% m/m” and “% v/v” are used to represent

the mass fraction and the volume fraction of a material, respectively.

NOTE 2 This method was evaluated with ethanol samples with different water contents (0,7 % m/m and 7 %

m/m) and acidity values (5 mg to 50 mg HAc per litre of sample).
2 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
2.1
total acidity

amount of acids contained in the ethanol sample, calculated as acetic acid, determined by potentiometric

titration with a strong alkaline solution, as given in this International Standard

3 Reagents and materials

3.1 Deionized water, with a maximum conductivity of 1 μS/cm, Grade 2 or equivalent.

3.2 Potassium hydrogen phthalate (KHC H O ), standard grade.
8 4 4
3.3 Solution of lithium chloride (LiCl) in ethanol, 1 mol/l to 3 mol/l.
3.4 Buffer solution, with pH 4 and pH 7.

NOTE The above values of pH are only indicative. The values shown on the buffer certificates are those which

are intended to be used in the analysis.

3.5 Hydrochloric acid solution (HCl), 1,0 mol/l, a solution prepared in accordance with the following

or a commercially available standardized hydrochloric acid solution of equivalent concentration.

— In order to prepare HCl, 1,0 mol/l, transfer (84,0 ± 0,5) ml of concentrated hydrochloric acid

(37 % v/v) to a 1 000 ml volumetric flask containing about its half capacity of water (3.1). Complete

the volume and homogenize the solution. Stock the solution in an amber flask at a temperature

below 25 °C.
— This solution has a 6 mo shelf life.
© ISO 2014 – All rights reserved 1
---------------------- Page: 6 ----------------------
ISO 17315:2014(E)
3.6 Sodium
...

DRAFT INTERNATIONAL STANDARD ISO/DIS 17315
ISO/TC 28/SC 7 Secretariat: DIN
Voting begins on Voting terminates on
2013-05-03 2013-08-03

INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION

Ethanol — Determination of total acidity by potenciometric
titration
Éthanol — Dosage de l'acidité totale par titration potentiométrique
ICS 75.160.20

To expedite distribution, this document is circulated as received from the committee

secretariat. ISO Central Secretariat work of editing and text composition will be undertaken at

publication stage.

Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du

secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au

Secrétariat central de l'ISO au stade de publication.

THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE

REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.

IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT

INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO

WHICH REFERENCE MAY BE MADE IN NATIONAL REGULATIONS.

RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH

THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
© International Organization for Standardization, 2013
---------------------- Page: 1 ----------------------
ISO/DIS 17315
COPYRIGHT PROTECTED DOCUMENT
© ISO 2013

All rights reserved. Unless otherwise specified, 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
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
E-mail [e-mail]
Web www.iso.org
Published in Switzerland
ii © ISO 2013 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/NP 17315
Contents Page

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

0 Introduction ........................................................................................................................................ iv

0.1 Warning .............................................................................................................................................. iv

0.2 Significance and use ......................................................................................................................... iv

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

2 Term and definition ............................................................................................................................. 1

2.1 Total acidity ......................................................................................................................................... 1

3 Reagents and materials ...................................................................................................................... 1

4 Apparatus ............................................................................................................................................ 2

5 Apparatus calibration ......................................................................................................................... 3

6 Procedure ............................................................................................................................................ 3

7 Calculation........................................................................................................................................... 4

8 Expression of results .......................................................................................................................... 4

9 Repeatability, r .................................................................................................................................... 5

10 Reproducibility, R ............................................................................................................................... 5

© ISO 2012 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/
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.

International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.

The main task of technical committees is to prepare International Standards. Draft International Standards

adopted by the technical committees are circulated to the member bodies for voting. Publication as an

International Standard requires approval by at least 75 % of the member bodies casting a vote.

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.

ISO/NP 17315 was prepared by Technical Committee ISO TC 28/SC 07/WG4.
0 Introduction
0.1 Warning

The use of this Standard may involve hazardous materials. This Standard does not purport to address all the

safety problems associated with its use. It is responsibility of the user of this Standard to establish appropriate

safety and health practices and determine the applicability of regulatory limitations prior to use.

0.2 Significance and use

Diluted hydrous solutions of organic acids, e.g. acetic acid, can corrode many materials. Thus, it is necessary

to determine and keep at low values the acid content in the final product.

An ethanol sample may have organic acids from the productive process, from its handling, contained in

additives, or due to sample degradation or contamination. The relative content of those components may be

determined by titration with a strong alkaline solution.

The numeric result of total acidity is a measure of the amount of acid components in the sample. Total acidity

is used as a quality control parameter of final product to prevent long-run corrosion problems.

For this reason, final product obtained from a blend of ethanol and others fuels must have a limited acidity.

iv © ISO 2012 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/NP 17315
Ethanol — Determination of total acidity by potenciometric
titration
1 Scope

This Standard specifies a test method for the determination of total acidity of ethanol by potentiometric titration.

The total acidity is reported as acetic acid mass (in mg) per ethanol volume (in l), or as mass percent of acetic

acid (% m/m), if the density of ethanol is known.
2 Term and definition
For the purposes of this Standard the following definition applies:
2.1 Total acidity

Amount of acids contained in the ethanol sample that can be titrated with a strong alkaline solution.

NOTE In this Standard total acidity is reported as acetic acid mass (in mg) per ethanol volume (in l), or as mass

percent of acetic acid (% m/m), if the density of ethanol is known.
3 Reagents and materials
3.1 Deionized water with a maximum conductivity of 1 μS/cm.
3.2 Potassium hydrogen phthalate (KHC H O ), reagent grade.
8 4 4
3.3 Solution of lithium chloride (LiCl) in ethanol, 1-3 mol/l.
3.4 Buffer solution with pH 4 and pH 7.
NOTE The above values of pH are only indicative. It shall
...