ISO-10565-1998.pdf
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1、A Reference number ISO 10565:1998(E) INTERNATIONAL STANDARD ISO 10565 Second edition 1998-08-15 Oilseeds Simultaneous determination of oil and water contents Method using pulsed nuclear magnetic resonance spectrometry Graines olagineuses Dtermination simultane de la teneur en huile et en eau Mthode
2、par spectromtrie par rsonance magntique nuclaire pulse Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:31:28 MDTNo reproduction or networking permitted without license from IH
3、S -,-,- ISO 10565:1998(E) ISO 1998 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 O
4、rganization for Standardization Case postale 56 CH-1211 Genve 20 Switzerland Internetisoiso.ch Printed in Switzerland ii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International S
5、tandards 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, al
6、so take part in the work. ISO 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 Internat
7、ional Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 10565 was prepared by Technical Committee ISO/TC 34, Agricultural food products, Subcommittee SC 2, Oleaginous seeds and fruits. This second edition cancels and replaces the first editio
8、n (ISO 10565:1993), which has been technically revised. Annexes A and B of this International Standard are for information only. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 0
9、2:31:28 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISOISO 10565:1998(E) 1 Oilseeds Simultaneous determination of oil and water contents Method using pulsed nuclear magnetic resonance spectrometry 1Scope This International Standard specifies a rap
10、id method for the determination of the oil and water contents of commercial oilseeds using pulsed nuclear magnetic resonance (NMR). It is applicable to rapeseeds, soya beans, linseeds and sunflower seeds with a water content less than 10 %. For seeds with higher water contents, drying is necessary b
11、efore the oil content can be determined by pulsed NMR. NOTE 1 This method has been tested with rapeseeds, soya beans, linseeds and sunflower seeds. This does not, however, preclude its applicability to other commercial seeds whose oil is liquid at the temperature of measurement. NOTE 2 The reproduci
12、bility values are generally higher than those obtained by the drying method (ISO 665). 2Normative references The following standards contain provisions which through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were
13、valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International
14、 Standards. ISO 659:1988, Oilseeds Determination of hexane extract (or light petroleum extract), called “oil content“. ISO 664:1990, Oilseeds Reduction of laboratory sample to test sample. ISO 665:1977, Oilseeds Determination of moisture and volatile matter content. 3Principle Insertion of the test
15、sample into the magnetic field of a pulsed NMR spectrometer. Application of an alternating electromagnetic field in the form of an intense 90 radiofrequency (RF) pulse which excites all the hydrogen nuclei. Recording of the free induction decay (FID) following the 90 pulse. The maximum amplitude of
16、this signal is proportional to the total number of protons from the water and oil phases of the sample. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/21/2007 02:31:28 MDTNo reproductio
17、n or networking permitted without license from IHS -,-,- ISO 10565:1998(E) ISO 2 Application of the second RF pulse, a so-called 180 pulse, to produce a spin-echo signal when only the signal from the oil phase contributes to the FID. NOTE 1 The maximum amplitude of this echo signal is proportional t
18、o the oil content. It varies with the sample temperature following a complex law. An increase in temperature decreases the measured value of the echo. Calculation of the difference between the two amplitudes, which is proportional to the water content. Automatic conversion of the measured signals, a
19、fter suitable calibration of the apparatus, into percentages of oil or water. NOTE 2 Simultaneous indications of the oil and water contents can be given by some spectrometers equipped with a minicomputer and a specific program. 4Calibration samples Calibration samples shall be homogeneous and free f
20、rom impurities. A definition of impurities is given in ISO 658 1. 4.1Samples for moisture-content calibration In order to obtain a reliable calibration curve, it is recommended that the water contents of the calibration samples be less than 10 % for all seeds. The water content of seeds can vary dep
21、ending on storage conditions. Water content shall therefore be determined in accordance with ISO 665 just prior to calibration. 4.2Samples for oil-content calibration Samples of oilseeds shall be of the same species as the test samples and of similar fatty acid compositions (for instance for the ana
22、lysis of rapeseeds which are rich in erucic acid, or sunflower seeds which are rich in oleic acid). Oil content shall be determined using the reference method specified in ISO 659. 5Apparatus Usual laboratory apparatus and, in particular, the following. 5.1Pulsed low-resolution NMR spectrometer, sui
23、table for measurement of the oil content and water content of oilseeds, and meeting the precision requirements of 11.2 and 11.3. The instruments parameters shall be in accordance with the instructions/specifications from the manufacturer. CAUTION Remove metallic objects from the proximity of the NMR
24、 spectrometer. 5.2Sample tubes, made of glass, suitable for use with the NMR spectrometer. 5.3Analytical balance, electronic, capable of weighing to an accuracy of 0,01 g. This equipment may be linked to the NMR spectrometer so that the sample mass is recorded directly by the NMR, or linked to a min
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