EN ISO 9289:1995
(Main)Oilseed residues - Determination of free residual hexane (ISO 9289:1991)
Oilseed residues - Determination of free residual hexane (ISO 9289:1991)
Specifies a method for the determination of hexane content after extraction with hydrocarbon-based solvents. Describes the principle, the reagents and materials, the apparatus, the sampling, the test procedure, the expression of results, and the contents of the test report.
Ölsaatrückstände (Extraktionsschrote) - Bestimmung des freien Resthexans (ISO 9289:1991)
Diese Internationale Norm legt ein Verfahren zur Bestimmung des freien, in den Ölkuchen nach Extraktion mit Lösungsmitteln auf Kohlenwasserstoffbasis noch enthaltenen Hexans fest.
Tourteaux de graines oléagineuses - Dosage de l'hexane résiduaire libre (ISO 9289:1991)
La présente Norme internationale prescrit une méthode de dosage de l'hexane résiduaire libre dans les tourteaux de graines oléagineuses après extraction par des solvants à base d'hydrocarbures.
Ostanki oljnih semen - Določevanje ostanka prostega heksana (ISO 9289:1991)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-1998
2VWDQNLROMQLKVHPHQ'RORþHYDQMHRVWDQNDSURVWHJDKHNVDQD ,62
Oilseed residues - Determination of free residual hexane (ISO 9289:1991)
Ölsaatrückstände (Extraktionsschrote) - Bestimmung des freien Resthexans (ISO
9289:1991)
Tourteaux de graines oléagineuses - Dosage de l'hexane résiduaire libre (ISO
9289:1991)
Ta slovenski standard je istoveten z: EN ISO 9289:1995
ICS:
67.200.20 Oljnice Oilseeds
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
INTERNATIONAL
STANDARD 9289
First edition
1991-07-15
-
- Determination of free
Oilseed residues
residual hexane
Tourteaux de graines okagineuses - Dosage de I’hexane rbidrraire
libre
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Reference number
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IS0 9289:1991(E)
Foreword
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
represented on that committee. International organizations, govern-
mental 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 electrotechnicai standardization.
Draft international Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an Inter-
national Standard requires approval by at least 75 % of the member
bodies casting a vote.
international Standard IS0 9289 was prepared by Technical Committee
ISO/TC 34, Agricultut-al food products.
0 IS0 1991
All rights reserved. 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 Organizati on for Standardiz ation
Case Postale 56 l CH-1 21 1 Get&e 20 * Switzerland
Printed in Switzerland
ii
IS0 9289:1991(E)
Introduction
The amount of hexane which can be desorbed rapidly from an oilseed
residue by heating is not necessarily equal to the total amount of re-
sidual hexane determined in accordance with IS0 88923987, Oilseed
residues - Determination of total residual hexane.
The “free residual hexane” is the amount of hexane desorbed by direct
heating of the oilseed residue without a preceding humidification of the
sample.
The difference between the total residual hexane and the free residual
hexane depends on several factors. in general, it increases with de-
creasing humidity of the oilseed residue examined, i.e. with increasing
dryness of the oilseed residue.
. . .
Ill
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IS0 9289:1991 (E)
INTERNATIONAL STANDARD
- Determination of free residual hexane
Oilseed residues
5 Reagents and materials
1 scope
All re a gents shai I be of recogn ized analytical grade
This International Standard specifies a method for
unles otherwise stated
the determination of the free residual hexane con- S
tent in oilseed residues after extraction with
hydrocarbon-based solvents.
5.1 Technical hexane or light petroleum, with a
composition similar to that used in the industrial
extraction of oilseeds or, failing these, n-hexane.
2 Normative reference
It is recommended that technical hexane be
NOTE 1
used for the calibration. This reagent usually contains
The following standard contains provisions which,
more than 50 O/o of n-hexane and consists predominantly
through reference in this text, constitute provisions
of C, isomers.
of this International Standard. At the time of publi-
cation, the edition indicated was valid. All standards
5.2 Internal standard: use either 5.2.1 or 5.2.2.
are subject to revision, and parties to agreements
based on this international Standard are encour-
NOTE 2 If the technical hexane used for the extraction
aged to investigate the possibility of applying the
or calibration contains appreciable amounts of cyclohex-
most recent edition of the standard indicated below.
ane, n-heptane should be used as the internal standard.
Members of IEC and IS0 maintain registers of cur-
rently valid International Standards.
5.2.1 Cyclohexane.
IS0 5500: 1986, Oilseed residues - Sampling.
52.2 n-Heptane.
3 Definition
5.3 Carrier gas, e.g. hydrogen, nitrogen, helium,
etc., thoroughly dried and containing less than
For the purposes of this International Standard, the
10 mg/kg of oxygen.
following definition applies.
5.4 Auxiliary gases.
free residual hexane: Proportion of volatile hydro-
carbons, referred to generally as hexane, remaining
5.4.1 Hydrogen, 99,9 % pure, containing no organic”
in oilseed residues after extraction with I__
impurrties.
hydrocarbon-based solvents and which is desorbed
directly by heating at 80 “C without the addition of
5.4.2 Air, containing no organic impurities.
water.
It is expressed as milligrams of n-hexane per kilo-
5.5 Calibration oilseed residues, of the same origin
gram of sample.
as the sample to be analysed and having a low
hexane content. If the hexane content is too high,
reduce it by spreading the residue in a thin layer
4 Principle
and leaving it to stand in the open air for several
hours.
Desorption of hexane by heating at 80 OC in a closed
vessel after addition of an internal standard. Deter-
Commercial oilseed residues usually have a
mination of the hexane content in the head-space moisture content of 12 % (m/m) to 14 % (m/m). In
by gas chromatography using capillary or packed the case of samples having a different moisture
content, it is necessary to carry out the calibration
columns.
IS0 9289:1991 (E)
NOTE 5 The septa often have a very high mechanical
with oilseed residues having the same moisture
resistance; if it is thought, therefore, that the needle of the
content as the sample.
gas syringe may be damaged by using it to perforate
septa, perforate them with a pin before taking the sample
from the head-space. Reuse of septa is not recommended.
6 Apparatus
Usual laboratory apparatus and, in particular, the
6.6 Metallic foil caps, for example made of alu-
following.
minium.
6.1 Gas chromatograph, with flame ionization de-
6.7 Crimping pliers, for closing the septum flasks.
tector and an integrator and/or recorder, equipped
with either
6.8 Liquid syringes, of 10 ~1 capacity.
a) a packed steel column approximately 2 m long
and of internal diameter approximately 3,2 mm,
packed with an acid-washed diatomaceous earth
7 Sampling and sample storage
support of particle size 150 p,m to 180 pm
(Chromosorb P NAW 60180 mesh’) is suitable),
Sampling shall have been carried out in accordance
and coated with 10 % squalane or methylpoly-
with IS0 5500. It is essential that loss of hexane from
siloxane (SE 30’) is suitable), or
the sample be prevented.
The laboratory sample shall fill a hermetically
b) a capillary column, approximately 30 m long and
sealed container (preferably a crimped metal box)
of 0,3 mm internal diameter, coated with methyl-
and shall be stored at 4 OC. Plastic containers shall
polysiloxane (SE 30’) is suitable) having a film
not be used.
thickness of 0,2 pm.
The determination of residual hexane shall b
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