EN ISO 3961:1999
(Main)Animal and vegetable fats and oils - Determination of iodine value (ISO 3961:1996)
Animal and vegetable fats and oils - Determination of iodine value (ISO 3961:1996)
Specifies a method for the determination of the iodine value of animal and vegetable fats and oils. Replaces the second edition.
Tierische und pflanzliche Fette und Öle - Bestimmung der Iodzahl (ISO 3961:1996)
Diese Internationale Norm legt ein Verfahren zur Bestimmung der Iodzahl in tierischen und pflanzlichen Fetten und Ölen, nachfolgend als Fette bezeichnet, fest.
Corps gras d'origines animale et végétale - Détermination de l'indice d'iode (ISO 3961:1996)
Spécifie les exigences générales en matière de qualité d'exécution des montages par brasage, au moyen de bornes, sur des substrats organiques, sur des cartes imprimées et stratifiés similaires, fixés à la surface de substrats inorganiques.
Elle s'applique aux assemblages entièrement ou partiellement réalisés par des bornes incluant des techniques de montage en surface ou d'autres techniques d'assemblage associées, par exemple trous traversants, fils.
Rastlinske in živalske maščobe in olja - Določevanje jodnega števila (ISO 3961:1996)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-maj-2000
5DVWOLQVNHLQåLYDOVNHPDãþREHLQROMD'RORþHYDQMHMRGQHJDãWHYLOD ,62
Animal and vegetable fats and oils - Determination of iodine value (ISO 3961:1996)
Tierische und pflanzliche Fette und Öle - Bestimmung der Iodzahl (ISO 3961:1996)
Corps gras d'origines animale et végétale - Détermination de l'indice d'iode (ISO
3961:1996)
Ta slovenski standard je istoveten z: EN ISO 3961:1999
ICS:
67.200.10 5DVWOLQVNHLQåLYDOVNH Animal and vegetable fats
PDãþREHLQROMD and oils
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL
STANDARD
Third edition
1996-06-o 1
Animal and vegetable fats and oils -
Determination of iodine value
Corps gras d’origines animale et vhghtale - D&termination de I’indice
d ‘iode
Reference number
IS0 3961 :I 996(E)
ord
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work of
preparing International Standards is normally carried out through IS0
technical committees. Each member body interested in a subject for which
a technical committee has been established has the right to be rep-
resented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. IS0
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard IS0 3961 was prepared by Technical Committee
ISO/TC 36, Agricultural food products, Subcommittee SC 1 I, Animal and
vegetable fats and oils.
This third edition cancels and replaces the second edition (IS0 3961 :I 989)
which has been technically revised.
Annexes A and B of this International Standard are for information only.
0 IS0 1996
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 the publisher.
International Organization for Standardization
Case postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
IS0 3961:1996(E)
INTERNATIONAL STANDARD @ IS0
Determination
Animal and vegetable fats and oils -
of iodine value
4 Principle
1 Scope
Dissolution of a test portion in solvent and addition of
This International Standard specifies a method for the
Wijs reagent. After a specified time, addition of pot-
determination of the iodine value of animal and veg-
assium iodide and water, and titration of the liberated
etable fats and oils, hereinafter referred to as fats.
iodine with sodium thiosulfate solution.
2 Normative references
5 Reagents
The following standards contain provisions which,
through reference in this text, constitute provisions of
Use only reagents of recognized analytical grade, and
this International Standard. At the time of publication,
water complying with grade 3 of IS0 3696.
the editions indicated were valid. All standards are
subject to revision, and parties to agreements based
5.1 Potassium iodide (KI), 100 g/l, not containing
on this International Standard are encouraged to
investigate the possibility of applying the most recent iodate or free iodine.
editions of the standards indicated below. Members
of IEC and IS0 maintain registers of currently valid
5.2 Starch solution.
International Standards.
Mix 5 g of soluble starch in 30 ml of water and add to
IS0 661: 1989, Animal and vegetable fats and oils -
1 000 ml of boiling water. Boil for 3 min and allow to
Preparation of test sample.
cool.
IS0 3696: 1987, Water for analytical laboratory use -
Specification and test methods. 5.3 Sodium thiosulfate, standard volumetric sol-
ution, c(Na&03.5H20) = 0,l mol/l, standardized not
more than 7 days before use.
3 Definition
5.4 Solvent, prepared by mixing equal volumes of
For the purposes of this International Standard, the
cyclohexane and glacial acetic acid.
following definition applies.
5.5 Wijs reagent, containing iodine monochloride in
3.1 iodine value: Mass of halogen, expressed as acetic acid.
iodine, absorbed by the test portion following the
specified procedure, divided by the mass of the test
The I/Cl ratio of the Wijs reagent shall be within the
portion.
limits l,lO~O,l.
Iodine value is expressed as grams per 100 g of fat. NOTE 1
Commercially available Wijs reagent can be used.
@ IS0
9.2 Determination
6 Apparatus
the
Usual labo ratory apparatus and, in particular,
9.2.1 Place the glass scoop containing the test
following.
portion in a 500 ml flask (6.2) and add the volume of
solvent (5.4) indicated in table 1. Add 25 ml of the
6.1 Glass weighing scoops, suitable for the test
Wijs reagent (5.5) by pipette. Insert the stopper, swirl
portion and for inserting into the flasks (6.2).
the contents and place the flask in the dark.
6.2 Conical flasks, of 500 ml capacity, fitted with
CAUTlON - Do not use a mouth pipette for the Wijs
ground glass stoppers and being completely dry.
reagent.
6.3 Analytical balance, capable of weighing to an
accuracy of +O,OOl g.
9.2.2 Prepare a blank with solvent and reagent as in
9.2.1 but omitting the test portion.
7 Sampling
9.2.3 For samples having an iodine value below 150
It is important that the laboratory receive a sample
leave the flasks in the dark for 1 h.
which is truly representative and has not been dam-
aged or changed during transport or storage.
For samples with iodine values above 150, and for
polymerized products and oils containing conjugated
Sampling is not part of the method specified in this
fatty acids (such as tung oil, dehydrated castor oil) and
International Standard. A recommended sampling
any oils containing keto fatty acids (such as some
method is given in IS0 5555.
grades of hydrogenated castor oil) and products
oxidized to a considerable extent, leave the flasks in
the dark for 2 h.
8 Preparation of test sample
Prepare the sample in accordance with the method 9.2.4 At the end of the reaction time (9.2.3), add
given in IS0 661. 20 ml of potassium iodide (5.1) and 150 ml of water.
Titrate with standard sodium thiosulfate solution (5.3)
9 Procedure
until the yellow colour due to iodine has almost disap-
peared. Add a few drops o
...
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