Petroleum products - Determination of boiling range distribution - Gas chromatography method (ISO 3924:2019)

This document specifies a method for the determination of the boiling range distribution of petroleum products. The method is applicable to petroleum products and fractions with a final boiling point of 538 °C or lower at atmospheric pressure as determined by this document. This document does not apply to gasoline samples or gasoline components. The method is limited to products having a boiling range greater than 55 °C and having a vapour pressure sufficiently low to permit sampling at ambient temperature. The document describes two procedures. a) Procedure A allows a larger selection of columns and analysis conditions, such as packed and capillary columns as well as a thermal conductivity detector in addition to the flame ionization detector. Analysis times range from 14 min to 60 min. b) Procedure B is restricted to only three capillary columns and requires no sample dilution. The analysis time is reduced to about 8 min. Both procedures have been successfully applied to samples containing fatty acid methyl esters (FAME) up to 20 % (volume fraction).

Mineralölerzeugnisse - Bestimmung des Siedeverlaufs - Gaschromatographisches Verfahren (ISO 3924:2019)

Dieses Dokument legt ein Verfahren zur Bestimmung des Siedeverlaufs von Mineralölerzeugnissen fest. Das Verfahren ist anwendbar auf Mineralölerzeugnisse und Fraktionen mit einem nach diesem Dokument bestimmten atmosphärischen Siedeende von 538 °C oder darunter. Dieses Dokument gilt nicht für Ottokraftstoffproben oder Ottokraftstoffkomponenten. Das Verfahren ist beschränkt auf Erzeugnisse mit einem Siedebereich größer als 55 °C und mit einem Dampfdruck, der niedrig genug ist, um eine Probenahme bei Umgebungstemperatur zu ermöglichen.
Dieses Dokument beschreibt zwei Verfahren.
a) Verfahren A bietet eine größere Auswahl von Säulen und Analysenbedingungen, wie z. B. gepackte Säulen und Kapillarsäulen, sowie einen Wärmeleitfähigkeitsdetektor zusätzlich zum Flammen-ionisationsdetektor. Die Analysenzeit liegt zwischen 14 min und 60 min.
b) Verfahren B ist auf nur drei Kapillarsäulen begrenzt und erfordert keine Probenverdünnung. Die Analysenzeit wird auf etwa 8 min verringert.
Beide Verfahren wurden erfolgreich auf Proben mit einem Gehalt von Fettsäuremethylestern (FAME, en: fatty acid methyl ester) bis zu 20 % (Volumenanteil) angewendet
ANMERKUNG Für die Zwecke dieses Dokuments wird zur Angabe des Massenanteils (μ) einer Substanz der Ausdruck „% (Massenanteil)“ und für den Volumenanteil (φ) einer Substanz der Ausdruck „% (Volumenanteil)“ verwendet.

Produits pétroliers - Détermination de la répartition dans l'intervalle de distillation - Méthode par chromatographie en phase gazeuse (ISO 3924:2019)

Le présent document spécifie une méthode pour déterminer la répartition dans l'intervalle de distillation des produits pétroliers. La méthode est applicable aux produits pétroliers et aux fractions pétrolières dont le point final de distillation est inférieur ou égal à 538 °C à la pression atmosphérique quand il est mesuré en appliquant le présent document. Celui-ci ne s'applique pas au cas des essences ou composés à base d'essences. Le domaine d'application de la méthode est limité aux produits dont l'intervalle de distillation est supérieur à 55 °C et dont la pression de vapeur est suffisamment basse pour permettre un échantillonnage à la température ambiante.
Ce document présente deux modes opératoires:
a) Le mode opératoire A propose une sélection élargie de colonnes, telles que des colonnes capillaires ou remplies, et de conditions d'analyse avec aussi bien un catharomètre qu'un détecteur à ionisation de flamme (FID). Les temps d'analyse s'étendent sur un intervalle de 14 à 60 min.
b) Le mode opératoire B ne propose que trois colonnes capillaires et ne nécessite pas de dilution de l'échantillon. Le temps d'analyse se réduit à environ 8 min.
Ces deux modes opératoires ont été appliqués avec succès à des échantillons contenant des esters méthyliques d'acides gras (EMAG) jusqu'à des teneurs de 20% (en fraction volumique).
NOTE Pour les besoins du présent document, les termes "% fraction massique" et "% fraction volumique" sont utilisés pour désigner la fraction massique (µ) d'un produit et sa fraction volumique (φ).

Naftni proizvodi - Določevanje destilacijskega območja - Metoda plinske kromatografije (ISO 3924:2019)

Ta dokument določa metodo za določevanje destilacijskega območja naftnih proizvodov. Metoda se uporablja za naftne proizvode in frakcije z zgornjo točko vretja pri temperaturi 538 °C ali manj pri atmosferskem tlaku, kot je določeno v tem dokumentu. Ta dokument se ne uporablja za vzorce bencina ali sestavine bencina. Metoda je omejena na proizvode z destilacijskim območjem nad 55 °C in dovolj nizkim parnim tlakom, ki zagotavlja vzorčenje pri temperaturi okolja. Dokument opisuje dva postopka. a) Postopek A omogoča večjo izbiro kolon in analiznih pogojev, kot so nasute ali kapilarne kolone ter tudi detektor toplotne prevodnosti poleg plamensko ionizacijskega detektorja. Časi analize zajemajo od 14 min do 60 min. b) Postopek B je omejen na samo tri kapilarne kolone, redčenje vzorca pa ni potrebno. Čas analize je skrajšan na približno 8 min. Oba postopka se uspešno uporabljata pri vzorcih, ki vsebujejo do 20 % (prostorninski delež) metil estrov maščobnih kislin (FAME).

General Information

Status
Published
Public Enquiry End Date
02-Oct-2017
Publication Date
30-Sep-2019
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
17-Sep-2019
Due Date
22-Nov-2019
Completion Date
01-Oct-2019

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SLOVENSKI STANDARD
SIST EN ISO 3924:2019
01-november-2019
Nadomešča:
SIST EN ISO 3924:2016
Naftni proizvodi - Določevanje destilacijskega območja - Metoda plinske
kromatografije (ISO 3924:2019)

Petroleum products - Determination of boiling range distribution - Gas chromatography

method (ISO 3924:2019)
Mineralölerzeugnisse - Bestimmung des Siedeverlaufs - Gaschromatographisches
Verfahren (ISO 3924:2019)

Produits pétroliers - Détermination de la répartition dans l'intervalle de distillation -

Méthode par chromatographie en phase gazeuse (ISO 3924:2019)
Ta slovenski standard je istoveten z: EN ISO 3924:2019
ICS:
71.040.50 Fizikalnokemijske analitske Physicochemical methods of
metode analysis
75.080 Naftni proizvodi na splošno Petroleum products in
general
SIST EN ISO 3924:2019 en,fr,de

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

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SIST EN ISO 3924:2019
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SIST EN ISO 3924:2019
EN ISO 3924
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2019
EUROPÄISCHE NORM
ICS 75.080 Supersedes EN ISO 3924:2016
English Version
Petroleum products - Determination of boiling range
distribution - Gas chromatography method (ISO
3924:2019)

Produits pétroliers - Détermination de la répartition Mineralölerzeugnisse - Bestimmung des Siedeverlaufs -

dans l'intervalle de distillation - Méthode par Gaschromatographisches Verfahren (ISO 3924:2019)

chromatographie en phase gazeuse (ISO 3924:2019)
This European Standard was approved by CEN on 30 June 2019.

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

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

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

member.

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

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

Centre has the same status as the official versions.

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

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

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

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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 3924:2019 E

worldwide for CEN national Members.
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SIST EN ISO 3924:2019
EN ISO 3924:2019 (E)
Contents Page

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

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SIST EN ISO 3924:2019
EN ISO 3924:2019 (E)
European foreword

This document (EN ISO 3924:2019) has been prepared by Technical Committee ISO/TC 28 "Petroleum

and related products, fuels and lubricants from natural or synthetic sources" in collaboration with

Technical Committee CEN/TC 19 “Gaseous and liquid fuels, lubricants and related products of

petroleum, synthetic and biological origin.” the secretariat of which is held by NEN.

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 March 2020, and conflicting national standards shall

be withdrawn at the latest by March 2020.

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 3924:2016.

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

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

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

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

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

United Kingdom.
Endorsement notice

The text of ISO 3924:2019 has been approved by CEN as EN ISO 3924:2019 without any modification.

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SIST EN ISO 3924:2019
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SIST EN ISO 3924:2019
INTERNATIONAL ISO
STANDARD 3924
Fifth edition
2019-07
Petroleum products — Determination
of boiling range distribution — Gas
chromatography method
Produits pétroliers — Détermination de la répartition dans l'intervalle
de distillation — Méthode par chromatographie en phase gazeuse
Reference number
ISO 3924:2019(E)
ISO 2019
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SIST EN ISO 3924:2019
ISO 3924:2019(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2019

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

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

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

below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Fax: +41 22 749 09 47
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2019 – All rights reserved
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SIST EN ISO 3924:2019
ISO 3924:2019(E)
Contents Page

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

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

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

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 2

5 Reagents and materials ................................................................................................................................................................................. 2

6 Apparatus ..................................................................................................................................................................................................................... 4

7 Sampling ........................................................................................................................................................................................................................ 7

8 Preparation of apparatus ............................................................................................................................................................................ 7

8.1 Column preparation ........................................................................................................................................................................... 7

8.1.1 General...................................................................................................................................................................................... 7

8.1.2 Packed columns ................................................................................................................................................................ 7

8.1.3 Capillary columns ........................................................................................................................................................... 7

8.2 Chromatograph ....................................................................................................................................................................................... 8

8.3 Column resolution ................................................................................................................................................................................ 8

8.4 Detector response check ................................................................................................................................................................ 9

8.5 Peak skewness ......................................................................................................................................................................................... 9

9 Calibration ...............................................................................................................................................................................................................10

9.1 Analysis sequence protocol .......................................................................................................................................................10

9.2 Baseline compensation analysis ...........................................................................................................................................11

9.3 Retention time versus boiling point calibration .....................................................................................................11

9.4 Analysis of reference material ................................................................................................................................................12

10 Procedure..................................................................................................................................................................................................................13

10.1 Sample preparation .........................................................................................................................................................................13

10.2 Sample analysis ...................................................................................................................................................................................14

11 Calculation ...............................................................................................................................................................................................................14

12 Expression of results .....................................................................................................................................................................................14

13 Precision ....................................................................................................................................................................................................................15

13.1 General ........................................................................................................................................................................................................15

13.2 Repeatability Procedure A .........................................................................................................................................................15

13.3 Reproducibility Procedure A ....................................................................................................................................................15

13.4 Repeatability Procedure B .........................................................................................................................................................16

13.5 Reproducibility Procedure B ....................................................................................................................................................16

13.6 Bias .................................................................................................................................................................................................................16

14 Test report ................................................................................................................................................................................................................17

Annex A (informative) Calculation of ISO 3405 equivalent data ..........................................................................................18

Annex B (normative) Reference material specified values and deviation limits ................................................21

Annex C (informative) Boiling points of non-normal n-alkane hydrocarbons ......................................................23

Annex D (informative) Boiling point revision ..........................................................................................................................................26

Annex E (informative) Alternative hydrogen and nitrogen carrier gases using Procedure B................27

Annex F (informative) Hydrogen and nitrogen carrier gases using Procedure A ...............................................34

Bibliography .............................................................................................................................................................................................................................39

© ISO 2019 – All rights reserved iii
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SIST EN ISO 3924:2019
ISO 3924:2019(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 28, Petroleum and related products, fuels

and lubricants from natural or synthetic sources.
[3] [4]
This method was originally based on the joined IP 406 and ASTM D2887 methods.

This fifth edition cancels and replaces the fourth edition (ISO 3924:2016), which has been technically

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

— The accelerated procedure has been moved from Annex B to the main body text. It is described

as Procedure B and has a precision and bias calculation in relation to Procedure A (the original

procedure).

— A new annex has been added with the newly defined boiling points for n-alkanes to keep the method

technically equivalent with IP 406 and ASTM D2887.

— Annexes E and F have been added with information on the use of alternative carrier gases.

— Several safety warnings and editorial updates have been made.

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 2019 – All rights reserved
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SIST EN ISO 3924:2019
INTERNATIONAL STANDARD ISO 3924:2019(E)
Petroleum products — Determination of boiling range
distribution — Gas chromatography method

WARNING — The use of this document can involve hazardous materials, operations and

equipment. This document does not purport to address all the safety problems associated with

its use. It is the responsibility of users of this document to take appropriate measures to ensure

the safety and health of personnel prior to application of the document.
1 Scope

This document specifies a method for the determination of the boiling range distribution of petroleum

products. The method is applicable to petroleum products and fractions with a final boiling point of

538 °C or lower at atmospheric pressure as determined by this document. This document does not

apply to gasoline samples or gasoline components. The method is limited to products having a boiling

range greater than 55 °C and having a vapour pressure sufficiently low to permit sampling at ambient

temperature.
The document describes two procedures.

a) Procedure A allows a larger selection of columns and analysis conditions, such as packed and

capillary columns as well as a thermal conductivity detector in addition to the flame ionization

detector. Analysis times range from 14 min to 60 min.

b) Procedure B is restricted to only three capillary columns and requires no sample dilution. The

analysis time is reduced to about 8 min.

Both procedures have been successfully applied to samples containing fatty acid methyl esters (FAME)

up to 20 % (volume fraction).

NOTE For the purposes of this document, the terms “% (mass fraction)” and “% (volume fraction)” are used

to represent the mass fraction (µ), the volume fraction (φ) of a material.
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 3170, Petroleum liquids — Manual sampling
ISO 3171, Petroleum liquids — Automatic pipeline sampling
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 http: //www .electropedia .org/
© ISO 2019 – All rights reserved 1
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SIST EN ISO 3924:2019
ISO 3924:2019(E)
3.1
initial boiling point
IBP

temperature corresponding to the retention time at which a net area count equal to 0,5 % of the total

sample area under the chromatogram is obtained
3.2
T10, T30, T50, T70, T90

temperature (T) corresponding to the retention time at which a net area count equal to the 10 %, 30 %,

50 %, 70 % or 90 % of the total sample area under the chromatogram is obtained
3.3
final boiling point
FBP

temperature corresponding to the retention time at which a net area count equal to 99,5 % of the total

sample area under the chromatogram is obtained
3.4
slice rate

number of data slices acquired per unit of time used to integrate the continuous (analogue)

chromatographic detector response during an analysis

Note 1 to entry: The slice rate is expressed in Hz (for example, slices per second).

4 Principle

A sample is introduced into a gas chromatographic column, which separates hydrocarbons in the order

of increasing boiling point. The column temperature is raised at a reproducible rate and the area under

the chromatogram is recorded throughout the analysis. Boiling temperatures are assigned to the time

axis from a calibration curve, obtained under the same conditions by running a known mixture of

hydrocarbons covering the boiling range expected in the sample. From these data, the boiling range

distribution is obtained.
[1][5][6]

Annex A presents a correlation model for the calculation of physical distillation equivalent data

from boiling range distribution analysis by gas chromatography determined following this document.

5 Reagents and materials

5.1 Stationary phase for columns, non-polar, that elutes hydrocarbons in boiling point order.

NOTE The following materials have been used successfully as liquid phases, other stationary phases can be

used, see 6.2.
For packed columns:
— silicone gum rubber UC-W98;
— silicone gum rubber GE-SE-30;
— silicone gum rubber OV-1;
— silicone gum rubber OV-101.
For capillary columns:
— polydimethylsiloxane.
2 © ISO 2019 – All rights reserved
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SIST EN ISO 3924:2019
ISO 3924:2019(E)

5.2 Solid support for packed columns, usually consisting of crushed fire brick or chromatographic

diatomaceous earth.

The particle size and support loading shall be such as to give optimum resolution and analysis time.

NOTE In general, support loadings of 3 % to 10 % have been found most satisfactory.

5.3 Carrier gas, with a minimum purity of 99,995 %, constituted of:

a) helium for use with flame ionization detectors (FIDs) or thermal conductivity detectors;

b) for the use of nitrogen or hydrogen as a carrier gas, see Annexes E and F.

CAUTION — Helium and nitrogen are compressed gases under high pressure. Hydrogen is an

extremely flammable gas under high pressure.
5.4 Hydrogen, grade suitable for FIDs.
CAUTION — Hydrogen is an extremely flammable gas under high pressure.
5.5 Compressed air, free of oil and water, regulated for FIDs.
CAUTION — Compressed air is a gas under high pressure and supports combustion.

5.6 Calibration mixture, consisting of an accurately weighed mixture of n-alkanes covering the range

from C to C and dissolved in carbon disulfide (5.8).
5 44

For packed columns, the final concentration in mass should be approximately 10 parts of the n-alkane

mixture to 100 parts of carbon disulfide. For capillary columns, the final concentration in mass should

be approximately 1 part of the n-alkane mixture to 100 parts of carbon disulfide.

The following mixture of n-alkanes has been found to be satisfactory for most samples: C , C , C , C ,

5 6 7 8

C , C , C , C , C , C , C , C , C , C , C , C , C . At least one component of the mixture shall

9 10 12 14 16 18 20 24 28 32 36 40 44

have a boiling point lower than the initial boiling point (IBP) of the sample and at least one component

shall have a boiling point higher than the final boiling point (FBP) of the sample. The boiling points of

n-alkanes are listed in Table 1.

If the test sample contains significant quantities of n-alkanes that can be identified on the chromatogram,

these peaks can be used as internal boiling point calibration points. However, it is advisable to use the

calibration mixture to be sure of peak identifications.

Propane and butane can be added non-quantitatively to the calibration mixture, if necessary, to conform

to 5.6. This can be done by bubbling a small amount of the gaseous hydrocarbon into a septum-sealed

vial of the calibration mixture using a gas syringe.

If stationary phases other than those listed in the note in 5.1 are used, the retention times of a few

alkylbenzenes across the boiling range, such as o-xylene, n-butylbenzene, 1,3,5-tri-isopropylbenzene,

n-decylbenzene and n-tetradecylbenzene, shall also be checked to make certain that the column is

separating according to the boiling point order (see Annex C).

5.7 Reference material, the primary reference material used shall be ASTM reference gas oil no. 1 or

no. 2 (as specified in Annex B).
5.8 Carbon disulfide, reagent grade or better (CAS RN 75-15-0).
CAUTION — Carbon disulfide is extremely volatile flammable and toxic.
© ISO 2019 – All rights reserved 3
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SIST EN ISO 3924:2019
ISO 3924:2019(E)
Table 1 — Boiling points of normal n-alkanes
Carbon no. Boiling point Carbon no. Boiling point
°C °C
2 −89 24 391
3 −42 25 402
4 0 26 412
5 36 27 422
6 69 28 431
7 98 29 440
8 126 30 449
9 151 31 458
10 174 32 466
11 196 33 474
12 216 34 481
13 235 35 489
14 254 36 496
15 271 37 503
16 287 38 509
17 302 39 516
18 316 40 522
19 330 41 528
20 344 42 534
21 356 43 540
22 369 44 545
23 380
[5]

NOTE API Project 44 is believed to have provided the original normal paraffin boiling point data that were listed in former

editions of this document. However, over the years, some of the data contained in both API Project 44 (Thermodynamics

Research Center Hydrocarbon Project) and the test methods have changed, and they are no longer equivalent. This table

represents the current normal paraffin boiling point values accepted by ISO, ASTM and the Energy Institute. Annex D

contains information about revised boiling points.
6 Apparatus

6.1 Chromatograph, any gas chromatograph that has the following performance characteristics can

be used.
6.1.1 Detector, of either the flame ionization or thermal conductivity type.

The detector shall have sufficient sensitivity to detect a mass fraction of 1,0 % of dodecane with a peak

height of at least 10 % of full scale under the conditions specified in this document, and without loss of

resolution as defined in 8.3. When operating at this sensitivity level, detector stability shall be such that

a baseline drift of not more than 1 % of full scale per hour is obtained. The detector shall be capable of

operating continuously at a temperature equivalent to the maximum column temperature employed.

The detector shall be connected to the column in such a way that any cold spots between the detector

and the column are avoided.

NOTE It is not desirable to operate thermal conductivity detectors at a temperature higher than the

maximum column temperature employed. Operation at higher temperatures only serves to shorten the useful

life of the detector, and generally contributes to higher noise levels and greater drift.

4 © ISO 2019 – All rights reserved
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SIST EN ISO 3924:2019
ISO 3924:2019(E)

6.1.2 Column temperature programmer, capable of programmed temperature operation over a

range sufficient to establish a retention time of at least 1 min for the IBP and to elute the entire sample

within the temperature ramp.

The programming rate shall be sufficiently reproducible to obtain retention time repeatability of 6 s for

each component in the calibration mixture (5.6).

6.1.3 Cryogenic column cooling. Column starting temperatures below ambient will be required if

samples with IBPs of less than 93 are to be analysed. This is typically provided by adding a source of

either liquid carbon dioxide or liquid nitrogen, controlled through the oven temperature circuitry.

However, excessively low initial column temperatures shall be avoided, to ensure that the stationary

phase remains liquid. The initial temperature of the column shall be only low enough to obtain a

calibration curve meeting the requirements of this document.

6.1.4 Sample inlet system. Programmed temperature vaporization (PTV) inlets or cool on-column

inlets shall be used for this method.

The sample inlet system shall be connected to the chromatographic column in such a way that any cold

spots between the inlet system and the column are avoided.

6.2 Column. Any column and conditions can be used, provided that, under the conditions of the test,

separations are in the order of boiling points as given in Table 1, and the column resolution, R , is at

least three (see 8.3). Typical column operating conditions are given in Tables 2, 3 and 4.

Table 2 — Typical operating conditions for packed columns — Procedure A
Parameter Column 1
Column length (m) 0,7
Column outside diameter (mm) 3,2
Stationary phase OV-101
Per cent stationary phase 5
Support material G
Support mesh size (μm) 80/100
Initial column temperature (°C) −40
Final column temperature (°C) 350
Programming rate (°C/min) 10
Carrier gas Helium
Carrier gas flow (ml/min)
...

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