ISO-3656-2002.pdf
《ISO-3656-2002.pdf》由会员分享,可在线阅读,更多相关《ISO-3656-2002.pdf(12页珍藏版)》请在三一文库上搜索。
1、 Reference number ISO 3656:2002(E) ISO 2002 INTERNATIONAL STANDARD ISO 3656 Third edition 2002-03-15 Animal and vegetable fats and oils Determination of ultraviolet absorbance expressed as specific UV extinction Corps gras dorigines animale et vgtale Dtermination de labsorbance dans lultraviolet, ex
2、prime sous la forme dextinction spcifique en lumire ultraviolette Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/23/2007 07:11:11 MDTNo reproduction or networking permitted without license from IHS -,-,
3、- ISO 3656:2002(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes 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 down
4、loading this file, parties accept therein the responsibility of not infringing Adobes 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
5、 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
6、given below. ISO 2002 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 ISOs mem
7、ber 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 copyrightiso.ch Web www.iso.ch Printed in Switzerland ii ISO 2002 All rights reserved Copyright International Organization for Standardization Provided
8、 by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/23/2007 07:11:11 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3656:2002(E) ISO 2002 All rights reserved iii Foreword ISO (the International Organization for Standardization) is a worldwid
9、e 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
10、 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 ac
11、cordance with the rules given in the ISO/IEC Directives, Part 3. 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 req
12、uires 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 International Standard may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 3656 was prepa
13、red by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils. This third edition cancels and replaces the second edition (ISO 3656:1989), which has been technically revised. Annex A of this International Standard is for information only. Copyright Inter
14、national Organization for Standardization Provided by IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/23/2007 07:11:11 MDTNo reproduction or networking permitted without license from IHS -,-,- Copyright International Organization for Standardization Provided by IHS under
15、license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/23/2007 07:11:11 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 3656:2002(E) ISO 2002 All rights reserved 1 Animal and vegetable fats and oils Determination of ultraviolet absorban
16、ce expressed as specific UV extinction 1 Scope This International Standard specifies a method for the determination of the absorbance at ultraviolet wavelengths of animal and vegetable fats and oils. 2 Normative reference The following normative document contains provisions which, through reference
17、in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying t
18、he most recent edition of the normative document indicated below. For undated references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain registers of currently valid International Standards. ISO 661:1989, Animal and vegetable fats and oils Preparati
19、on of test sample 3 Principle In a specified ultraviolet wavelength range, the absorbance of a sample in solution is measured spectrometrically. The absorbance at a concentration of 1 g per 100 ml in a 10 mm cell is calculated. 4 Reagent Use only reagents of recognized analytical grade, unless other
20、wise stated. 4.1 Solvent: 2,2,4-trimethylpentane (isooctane), having an absorbance less than 0,12 at 230 nm and less than 0,05 at 250 nm against distilled water, measured in a cell of thickness 10 mm. If 2,2,4-trimethylpentane is not available, cyclohexane or n-hexane having the characteristics spec
21、ified above may be used instead. 5 Apparatus The glassware used for the determination shall be thoroughly cleaned and rinsed with the solvent (4.1) before use so that it is free from impurities having an absorbance within the wavelength range of 220 nm to 320 nm. Usual laboratory apparatus and, in p
22、articular, the following. 5.1 Spectrometer, preferably having a recording instrument, with quartz cells of thickness 10 mm, suitable for measurements at ultraviolet wavelengths. Before use it is recommended that the wavelength and absorbance scales of the spectrometer be checked as follows. a) Wavel
23、ength scale This may be checked using a mercury lamp, in accordance with the instrument manufacturers instructions. Alternatively a holmium glass plate, which displays sharp absorption peaks at 279,37 nm and 287,5 nm, may be used. Copyright International Organization for Standardization Provided by
24、IHS under license with ISO Licensee=Aramco HQ/9980755100 Not for Resale, 04/23/2007 07:11:11 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3656:2002(E) 2 ISO 2002 All rights reserved b) Absorbance scale Prepare a 200 mg/l solution of analytical grade potassium chromat
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- ISO 3656 2002
链接地址:https://www.31doc.com/p-3778005.html