ISO 779:2005

INTERNATIONAL ISO
STANDARD 779
Third edition
2005-05-01


Paper, board and pulp — Determination
of acid-soluble iron
Papier, carton et pâte — Détermination de la teneur en fer soluble dans
l'acide




Reference number
ISO 779:2005(E)
©
ISO 2005

---------------------- Page: 1 ----------------------
ISO 779:2005(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2005
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing 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 copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2005 – All rights reserved

---------------------- Page: 2 ----------------------
ISO 779:2005(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.
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 779 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps.
This third edition cancels and replaces the second edition (ISO 779:2001), of which it constitutes a minor
revision. Apart from minor editorial modifications, only the title has been changed, to be consistent with
ISO 1830:2005, and to make a distinction with ISO 17812 (to be published) which specifies the method to
determine the total mass fraction of calcium, manganese, iron and copper.
The first edition of this International Standard included the photometric procedure as well as the procedure
based on atomic absorption spectroscopy. In the second edition, the photometric procedure was deleted, as it
is now seldom used, and the scope was enlarged to include paper and board in addition to pulp.
© ISO 2005 – All rights reserved iii

---------------------- Page: 3 ----------------------
ISO 779:2005(E)
Introduction
[1] [2]
This International Standard corresponds to ISO 777 and ISO 778 in order to make it possible to perform
the final measurement of all three elements on the same solution.

iv © ISO 2005 – All rights reserved

---------------------- Page: 4 ----------------------
INTERNATIONAL STANDARD ISO 779:2005(E)

Paper, board and pulp — Determination of acid-soluble iron
WARNING — The method specified in this International Standard involves the use of some hazardous
chemicals and of gases that can form explosive mixtures with air. Care must be taken to ensure that
the relevant precautions are observed.
1 Scope
This International Standard specifies the procedure for the determination of acid-soluble iron by atomic
absorption spectrometry or by plasma emission spectrometry.
It is applicable to all kinds of paper, board and pulp.
It specifies a method to determine the acid-soluble part of the incineration residue, i.e. that part of the ignition
residue obtained after incineration which is soluble in hydrochloric acid. If the residue is completely soluble,
the result obtained by the procedure specified in this International Standard is taken as the total amount of
iron in the sample.
2 Normative references
The following referenced documents are indispensable for the application 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 186, Paper and board — Sampling to determine average quality
ISO 287, Paper and board — Determination of moisture content — Oven-drying method
ISO 638, Pulps — Determination of dry matter content
ISO 1762, Paper, board and pulps — Determination of residue (ash) on ignition at 525 °C
ISO 7213, Pulps — Sampling for testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
mass fraction of iron
amount of the element iron in the solution obtained after incineration of the specimen at 525 °C and treating
the residue with 6 mol/l hydrochloric acid, as specified in this International Standard
© ISO 2005 – All rights reserved 1

---------------------- Page: 5 ----------------------
ISO 779:2005(E)
4 Principle
A test portion is incinerated at 525 °C and the residue is treated with 6 mol/l hydrochloric acid. The test
solution is aspirated into an acetylene/dinitrogen monoxide or acetylene/air flame and the mass fraction of iron
is determined by one of the following procedures:
 measurement of the absorption of the 248,3 nm line emitted by an iron hollow-cathode lamp, or
 measurement of the absorption of the 248,3 nm line emitted by plasma emission spectrometry.
5 Reagents and materials
Use only chemicals of recognized analytical grade and only distilled or deionized water.
5.1 Hydrochloric acid, about 6 mol/l.
Dilute 500 ml of hydrochloric acid (density 1,19 g/ml) in 500 ml of water.
5.2 Iron stock solution, 100 mg/l of Fe.
Dissolve 100 mg of pure iron wire in the smallest quantity possible of hydrochloric acid (density 1,19 g/ml) in a
1 000 ml volumetric flask. Dilute with water to the mark and mix.
1 ml of this stock solution contains 0,10 mg of Fe.
5.3 Iron standard solution, 10 mg/l of Fe.
Transfer 100 ml of the iron stock solution (5.2) to a 1 000 ml volumetric flask and add 200 ml of hydrochloric
acid (5.1). Dilute with water to the mark and mix.
...

SLOVENSKI STANDARD
SIST ISO 779:2011
01-maj-2011
3DSLUNDUWRQOHSHQNDLQYODNQLQH'RORþHYDQMHåHOH]DWRSQHJDYNLVOLQL
Paper, board and pulp -- Determination of acid-soluble iron
Papier, carton et pâte -- Détermination de la teneur en fer soluble dans l'acide
Ta slovenski standard je istoveten z: ISO 779:2005
ICS:
85.040 Vlaknine Pulps
85.060 Papir, karton in lepenka Paper and board
SIST ISO 779:2011 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

SIST ISO 779:2011

---------------------- Page: 2 ----------------------

SIST ISO 779:2011


INTERNATIONAL ISO
STANDARD 779
Third edition
2005-05-01


Paper, board and pulp — Determination
of acid-soluble iron
Papier, carton et pâte — Détermination de la teneur en fer soluble dans
l'acide




Reference number
ISO 779:2005(E)
©
ISO 2005

---------------------- Page: 3 ----------------------

SIST ISO 779:2011
ISO 779:2005(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.


©  ISO 2005
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing 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 copyright@iso.org
Web www.iso.org
Published in Switzerland

ii © ISO 2005 – All rights reserved

---------------------- Page: 4 ----------------------

SIST ISO 779:2011
ISO 779:2005(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.
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 779 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps.
This third edition cancels and replaces the second edition (ISO 779:2001), of which it constitutes a minor
revision. Apart from minor editorial modifications, only the title has been changed, to be consistent with
ISO 1830:2005, and to make a distinction with ISO 17812 (to be published) which specifies the method to
determine the total mass fraction of calcium, manganese, iron and copper.
The first edition of this International Standard included the photometric procedure as well as the procedure
based on atomic absorption spectroscopy. In the second edition, the photometric procedure was deleted, as it
is now seldom used, and the scope was enlarged to include paper and board in addition to pulp.
© ISO 2005 – All rights reserved iii

---------------------- Page: 5 ----------------------

SIST ISO 779:2011
ISO 779:2005(E)
Introduction
[1] [2]
This International Standard corresponds to ISO 777 and ISO 778 in order to make it possible to perform
the final measurement of all three elements on the same solution.

iv © ISO 2005 – All rights reserved

---------------------- Page: 6 ----------------------

SIST ISO 779:2011
INTERNATIONAL STANDARD ISO 779:2005(E)

Paper, board and pulp — Determination of acid-soluble iron
WARNING — The method specified in this International Standard involves the use of some hazardous
chemicals and of gases that can form explosive mixtures with air. Care must be taken to ensure that
the relevant precautions are observed.
1 Scope
This International Standard specifies the procedure for the determination of acid-soluble iron by atomic
absorption spectrometry or by plasma emission spectrometry.
It is applicable to all kinds of paper, board and pulp.
It specifies a method to determine the acid-soluble part of the incineration residue, i.e. that part of the ignition
residue obtained after incineration which is soluble in hydrochloric acid. If the residue is completely soluble,
the result obtained by the procedure specified in this International Standard is taken as the total amount of
iron in the sample.
2 Normative references
The following referenced documents are indispensable for the application 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 186, Paper and board — Sampling to determine average quality
ISO 287, Paper and board — Determination of moisture content — Oven-drying method
ISO 638, Pulps — Determination of dry matter content
ISO 1762, Paper, board and pulps — Determination of residue (ash) on ignition at 525 °C
ISO 7213, Pulps — Sampling for testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
mass fraction of iron
amount of the element iron in the solution obtained after incineration of the specimen at 525 °C and treating
the residue with 6 mol/l hydrochloric acid, as specified in this International Standard
© ISO 2005 – All rights reserved 1

---------------------- Page: 7 ----------------------

SIST ISO 779:2011
ISO 779:2005(E)
4 Principle
A test portion is incinerated at 525 °C and the residue is treated with 6 mol/l hydrochloric acid. The test
solution is aspirated into an acetylene/dinitrogen monoxide or acetylene/air flame and the mass fraction of iron
is determined by one of the following procedures:
 measurement of the absorption of the 248,3 nm line emitted by an iron hollow-cathode lamp, or
 measurement of the absorption of the 248,3 nm line emitted by plasma emission spectrometry.
5 Reagents and materials
Use only chemicals of recognized analytical grade and only distilled or deionized water.
5.1 Hydrochloric acid, about 6 mol/l.
Dilute 500 ml of hydrochloric acid (density 1,19 g/ml) in 500 ml of water.
5.2 Iron stock solution, 100 mg/l of Fe.
Dissolve 100 mg o
...

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Papier, carton et pâte -- Détermination de la teneur en fer soluble dans l'acidePaper, board and pulp -- Determination of acid-soluble iron85.060Papir, karton in lepenkaPaper and board85.040VlakninePulpsICS:Ta slovenski standard je istoveten z:ISO 779:2005oSIST ISO 779:2011en01-marec-2011oSIST ISO 779:2011SLOVENSKI
STANDARD



oSIST ISO 779:2011



Reference numberISO 779:2005(E)© ISO 2005
INTERNATIONAL STANDARD ISO779Third edition2005-05-01Paper, board and pulp — Determination of acid-soluble iron Papier, carton et pâte —Détermination de la teneur en fer soluble dans l'acide
oSIST ISO 779:2011



ISO 779:2005(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
©
ISO 2005 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing 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
copyright@iso.org Web
www.iso.org Published in Switzerland
ii © ISO 2005 – All rights reserved
oSIST ISO 779:2011



ISO 779:2005(E) © ISO 2005 – All rights reserved iii 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 779 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps. This third edition cancels and replaces the second edition (ISO 779:2001), of which it constitutes a minor revision. Apart from minor editorial modifications, only the title has been changed, to be consistent with ISO 1830:2005, and to make a distinction with ISO 17812 (to be published) which specifies the method to determine the total mass fraction of calcium, manganese, iron and copper. The first edition of this International Standard included the photometric procedure as well as the procedure based on atomic absorption spectroscopy. In the second edition, the photometric procedure was deleted, as it is now seldom used, and the scope was enlarged to include paper and board in addition to pulp. oSIST ISO 779:2011



ISO 779:2005(E) iv © ISO 2005 – All rights reserved Introduction This International Standard corresponds to ISO 777 [1] and ISO 778 [2] in order to make it possible to perform the final measurement of all three elements on the same solution.
oSIST ISO 779:2011



INTERNATIONAL STANDARD ISO 779:2005(E) © ISO 2005 – All rights reserved 1 Paper, board and pulp — Determination of acid-soluble iron WARNING — The method specified in this International Standard involves the use of some hazardous chemicals and of gases that can form explosive mixtures with air. Care must be taken to ensure that the relevant precautions are observed. 1 Scope This International Standard specifies the procedure for the determination of acid-soluble iron by atomic absorption spectrometry or by plasma emission spectrometry. It is applicable to all kinds of paper, board and pulp. It specifies a method to determine the acid-soluble part of the incineration residue, i.e. that part of the ignition residue obtained after incineration which is soluble in hydrochloric acid. If the residue is completely soluble, the result obtained by the procedure specified in this International Standard is taken as the total amount of iron in the sample. 2 Normative references The following referenced documents are indispensable for the application 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 186, Paper and board — Sampling to determine average quality ISO 287, Paper and board — Determination of moisture content — Oven-drying method ISO 638, Pulps — Determination of dry matter content ISO 1762, Paper, board and pulps — Determination of residue (ash) on ignition at 525 °C ISO 7213, Pulps — Sampling for testing 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 mass fraction of iron amount of the element iron in the solution obtained after incineration of the specimen at 525 °C and treating the residue with 6 mol/l hydrochloric acid, as specified in this International Standard oSIST ISO 779:2011



ISO 779:2005(E) 2 © ISO 2005 – All rights reserved 4 Principle A test portion is incinerated at 525 °C and the residue is treated with 6 mol/l hydrochloric acid. The test solution is aspirated into an acetylene/dinitrogen monoxide or acetylene/air flame and the mass fraction of iron is determined by one of the following procedures: =measurement of the absorption of the 248,3 nm line emitted by an iron hollow-cathode lamp, or =measurement of the absorption of the 248,3 nm line emitted by plasma emission spectrometry. 5 Reagents and materials Use only chemicals of recognized analytical grade and only distilled or deionized water. 5.1 Hydrochloric acid, about 6 mol/l. Dilute 500 ml of hydrochloric acid (density 1,19 g/ml) in 500 ml of water. 5.2 Iron stock solution, 100 mg/l of Fe. Dissolve 100 mg of pure iron wire in the smallest quantity possible of
...

NORME ISO
INTERNATIONALE 779
Troisième édition
2005-05-01



Papier, carton et pâte — Détermination de
la teneur en fer soluble dans l'acide
Paper, board and pulp — Determination of acid-soluble iron




Numéro de référence
ISO 779:2005(F)
©
ISO 2005

---------------------- Page: 1 ----------------------
ISO 779:2005(F)
PDF – Exonération de responsabilité
Le présent fichier PDF peut contenir des polices de caractères intégrées. Conformément aux conditions de licence d'Adobe, ce fichier
peut être imprimé ou visualisé, mais ne doit pas être modifié à moins que l'ordinateur employé à cet effet ne bénéficie d'une licence
autorisant l'utilisation de ces polices et que celles-ci y soient installées. Lors du téléchargement de ce fichier, les parties concernées
acceptent de fait la responsabilité de ne pas enfreindre les conditions de licence d'Adobe. Le Secrétariat central de l'ISO décline toute
responsabilité en la matière.
Adobe est une marque déposée d'Adobe Systems Incorporated.
Les détails relatifs aux produits logiciels utilisés pour la création du présent fichier PDF sont disponibles dans la rubrique General Info
du fichier; les paramètres de création PDF ont été optimisés pour l'impression. Toutes les mesures ont été prises pour garantir
l'exploitation de ce fichier par les comités membres de l'ISO. Dans le cas peu probable où surviendrait un problème d'utilisation,
veuillez en informer le Secrétariat central à l'adresse donnée ci-dessous.


©  ISO 2005
Droits de reproduction réservés. Sauf prescription différente, aucune partie de cette publication ne peut être reproduite ni utilisée sous
quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit
de l'ISO à l'adresse ci-après ou du comité membre de l'ISO dans le pays du demandeur.
ISO copyright office
Case postale 56 • CH-1211 Geneva 20
Tel. + 41 22 749 01 11
Fax. + 41 22 749 09 47
E-mail copyright@iso.org
Web www.iso.org
Publié en Suisse

ii © ISO 2005 – Tous droits réservés

---------------------- Page: 2 ----------------------
ISO 779:2005(F)
Avant-propos
L'ISO (Organisation internationale de normalisation) est une fédération mondiale d'organismes nationaux de
normalisation (comités membres de l'ISO). L'élaboration des Normes internationales est en général confiée
aux comités techniques de l'ISO. Chaque comité membre intéressé par une étude a le droit de faire partie du
comité technique créé à cet effet. Les organisations internationales, gouvernementales et non
gouvernementales, en liaison avec l'ISO participent également aux travaux. L'ISO collabore étroitement avec
la Commission électrotechnique internationale (CEI) en ce qui concerne la normalisation électrotechnique.
Les Normes internationales sont rédigées conformément aux règles données dans les Directives ISO/CEI,
Partie 2.
La tâche principale des comités techniques est d'élaborer les Normes internationales. Les projets de Normes
internationales adoptés par les comités techniques sont soumis aux comités membres pour vote. Leur
publication comme Normes internationales requiert l'approbation de 75 % au moins des comités membres
votants.
L'attention est appelée sur le fait que certains des éléments du présent document peuvent faire l'objet de
droits de propriété intellectuelle ou de droits analogues. L'ISO ne saurait être tenue pour responsable de ne
pas avoir identifié de tels droits de propriété et averti de leur existence.
L'ISO 779 a été élaborée par le comité technique ISO/TC 6, Papiers, cartons et pâtes.
Cette troisième édition annule et remplace la deuxième édition (ISO 779:2001), dont elle constitue une
révision mineure. Outre des modifications d'ordre rédactionnel, seul le titre a été modifié, afin d'assurer une
cohérence avec l'ISO 1830:2005 et une distinction avec l'ISO 17812 (à publier) qui spécifie la méthode pour
déterminer la fraction massique totale en calcium, en manganèse, en fer et en cuivre.
La première édition de la présente Norme internationale décrivait la méthode photométrique et la méthode
basée sur la spectrométrie d'absorption atomique. Dans la deuxième édition, la méthode photométrique avait
été éliminée, car elle est rarement utilisée de nos jours, et le domaine d'application avait été élargi pour
inclure le papier et le carton, en plus de la pâte.
© ISO 2005 – Tous droits réservés iii

---------------------- Page: 3 ----------------------
ISO 779:2005(F)
Introduction
[1] [2]
La présente Norme internationale correspond à l'ISO 777 et à l'ISO 778 ; il est donc possible d'obtenir
des mesures finales des trois éléments pour la même solution.

iv © ISO 2005 – Tous droits réservés

---------------------- Page: 4 ----------------------
NORME INTERNATIONALE ISO 779:2005(F)

Papier, carton et pâte — Détermination de la teneur en fer
soluble dans l'acide
AVERTISSEMENT — La méthode spécifiée dans la présente Norme internationale prévoit l'utilisation
de produits chimiques dangereux et de gaz qui peuvent former des mélanges explosifs avec l'air.
S'assurer que les mesures de sécurité nécessaires ont été prises.
1 Domaine d'application
La présente Norme internationale spécifie une méthode de détermination de la teneur en fer soluble dans
l'acide par spectrométrie d'absorption atomique ou par spectrométrie d'émission de plasma.
Elle est applicable à tous les types de papier, de carton et de pâte.
Elle spécifie une méthode de détermination de la partie soluble dans l'acide des résidus d'incinération, à
savoir la partie des cendres qui est soluble dans l'acide chlorhydrique. Si le résidu est complètement soluble,
le résultat obtenu, en utilisant la procédure spécifiée dans la présente Norme internationale, correspond à la
quantité totale de fer dans l'échantillon.
2 Références normatives
Les documents de référence suivants sont indispensables pour l'application du présent document. Pour les
références datées, seule l'édition citée s'applique. Pour les références non datées, la dernière édition du
document de référence s'applique (y compris les éventuels amendements).
ISO 186, Papier et carton — Échantillonnage pour déterminer la qualité moyenne
ISO 287, Papier et carton — Détermination de l'humidité — Méthode par séchage à l'étuve
ISO 638, Pâtes — Détermination de la teneur en matières sèches
ISO 1762, Papier, carton et pâtes — Détermination du résidu (cendres) après incinération à 525 °C
ISO 7213, Pâtes — Échantillonnage pour essais
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s'appliquent.
3.1
fraction massique de fer
quantité de fer présente dans la solution après incinération de l'éprouvette à 525 °C et traitement du résidu
avec de l'acide chlorhydrique à 6 mol/l, conformément à la présente Norme internationale
© ISO 2005 – Tous droits réservés 1

---------------------- Page: 5 ----------------------
ISO 779:2005(F)
4 Principe
Incinérer une prise d'essai à 525 °C et traiter le résidu avec de l'acide chlorhydrique à 6 mol/l. Aspirer la
solution d'essai dans une flamme d'acétylène/monoxyde de diazote ou une flamme aéro-acétylénique, et
déterminer la fraction massique de fer par l'un des deux procédés suivants:
 mesure de l'absorption de la ligne de 248,3 nm émise par une lampe à cathode creuse au fer, ou
 mesure de l'absorption de la ligne de 248,3 nm émise par un spectromètre à émission de plasma.
5 Réactifs et matériaux
Utiliser uniquement des produits chimiques de qualité analytique reconnue et de l'eau distillée ou déionisée.
5.1 Acide chlorhydrique, 6 mol/l environ.
Diluer 500 ml d'acide chlorhydrique (densité de 1,19 g/ml) dans 500 ml d'eau.
5.2 Solution mère de fer, 100 mg/l de Fe.
Diluer 100 mg de fil de fer pur dans la plus petite quantité possible d'acide chlorhydrique (densité de
1,19 g/ml) dans une fiole jaugée de 1 000 ml. Diluer avec de l'eau jusqu'au trait et mélanger.
1 ml de cette solution mère contient 0,10 mg de Fe.
5.3 Solution étalon de fer, 100 mg/l de Fe.
Transférer 100 ml de la solution mère (5.2) dans une fiole jaugée de 1 000 ml et ajouter 200 ml d'acide
chlorhydrique (5.1). Diluer avec de l'eau jusqu'au trait et mélanger.
1 ml de c
...