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1、BRITISH STANDARD BS EN ISO 6800:1998 BS 684-2-2.39: 1998 Animal and vegetable fats and oils Determination of the composition of fatty acids in the 2-position of the triglyceride molecules The European Standard EN ISO 6800:1997 has the status of a British Standard. ICS 67.200.10 Licensed Copy: sheffi
2、eldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 6800:1998 This British Standard, having been prepared under the direction of the Consumer Products and Services Sector Board, was published under the authority of the Standards Board and comes into effect
3、 on 15 May 1998 BSI 04-1999 ISBN 0 580 29270 3 National foreword This British Standard is the English language version of EN ISO 6800:1997. It is identical with ISO 6800:1997. It supersedes BS 684-2-2.39:1986 which is withdrawn. The UK participation in its preparation was entrusted to Technical Comm
4、ittee AW/11, Animal and vegetable fats and oils, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related intern
5、ational and European developments and promulgate them in the UK. A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references Attention is drawn to the fact that CEN and CENELEC standards normally include an annex which lists normative reference
6、s to international publications with their corresponding European publications. The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Ind
7、ex”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself c
8、onfer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, the EN ISO title page, page 2, the ISO title page, pages ii to iv, pages 1 to 7 and a back cover. This standard has been updated (see copyright date) and may have had
9、 amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN ISO 6800:1998 BSI 04-1999i Cont
10、ents Page National forewordInside front cover Foreword2 Forewordiii Text of ISO 68001 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI ii blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy,
11、 (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 6800 December 1997 ICS 67.200.00 Descriptors: See ISO document English version Animal and vegetable fats and oils Determination of the composition of fatty acids in the 2-position of the triglycerides molecules (ISO 6800:1997) Corps g
12、ras dorigines animale et vgtale Dtermination de la composition des acides gras en position 2 dans les triglycrides (ISO 6800:1997) Tierische und pflanzliche Fette und le Bestimmung der Zusammensetzung von Fettsuren in der 2-Stellung von Triglyceridmoleklen (ISO 6800:1997) This European Standard was
13、approved by CEN on 9 January 1998. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nati
14、onal standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and no
15、tified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland
16、 and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1997 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No
17、. EN ISO 6800:1997 E Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 6800:1997 BSI 04-1999 2 Foreword The text of the International Standard ISO 6800:1997 has been prepared by Technical Committee ISO/TC 34 “Agricultural food products”
18、 in collaboration with Technical Committee CEN/TC 307 “Oilseeds, vegetable and animal fats and oils and their by-products Methods of sampling and analysis”, the secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an
19、 identical text or by endorsement, at the latest by June 1998, and conflicting national standards shall be withdrawn at the latest by June 1998. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Sta
20、ndard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO 6800:1997 was approved by CEN as a
21、European Standard without any modification. Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 6800:1997 ii BSI 04-1999 Contents P
22、age Forewordiii 1Scope1 2Normative references1 3Principle1 4Reagents1 5Apparatus2 6Sampling2 7Preparation of test sample2 8Procedure2 9Expression of results4 10Precision4 11Test report4 Annex A (normative) Preparation of the lipase and checking its activity5 Annex B (informative) Results of interlab
23、oratory tests5 Annex C (informative) Bibliography7 Table B.1 Statistical results of study on pork and beef fats using a packed column6 Table B.2 Statistical results of study on olive oil using the capillary column GLC method7 Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00
24、2006, Uncontrolled Copy, (c) BSI EN ISO 6800:1997 BSI 04-1999iii 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 c
25、ommittees. 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 t
26、he 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
27、member bodies casting a vote. International Standard ISO 6800 was prepared by Technical Committee ISO/TC 34, Agricultural food products, Subcommittee SC 11, Animal and vegetable fats and oils. This second edition cancels and replaces the first edition (ISO 6800:1985), which has been technically revi
28、sed. Annex A to Annex C of this International Standard are for information only. Descriptors: Agricultural products, food products, animal fats, vegetable fats, animal oils, vegetable oils, fatty acids, chemical analysis, determination, chemical composition, gas phase chromatography. Licensed Copy:
29、sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI iv blank Licensed Copy: sheffieldun sheffieldun, na, Sun Nov 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 6800:1997 BSI 04-19991 1 Scope This International Standard specifies a method for the
30、 determination of the composition of fatty acids which are esterified in the 2-position ( or internal position) of the triglyceride molecules in animal and vegetable fats and oils. Because of the nature of pancreatic lipase action, the method is applicable only to fats and oils with a melting point
31、below 45 C. The method is not unreservedly applicable to all fats and oils, particularly those containing substantial amounts of fatty acids with 12 or fewer carbon atoms (e.g. copra oil, palm kernel oil, butyric butter fats); fatty acids with 20 and more carbon atoms and of a high degree of unsatur
32、ation (more than four double bonds) (e.g. fish oil and marine animal oil); fatty acids which have secondary groups containing oxygen. NOTEFatty acids with double bonds in the (n-16) to (n-11) position (e.g. petroselinic acid) are converted only very slowly by pancreatic lipase. This may lead to wron
33、g results. 2 Normative 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 valid. All standards are subject to revision, and parties to agreements ba
34、sed 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 Standards. ISO 660:1996, Animal and vegetable fats and oils Determination
35、 of acid value and of acidity. ISO 661:1989, Animal and vegetable fats and oils Preparation of test sample. ISO 3696:1987, Water for analytical laboratory use Specification and test methods. ISO 5508:1990, Animal and vegetable fats and oils Analysis by gas chromatography of methyl esters of fatty ac
36、ids. ISO 5509:1), Animal and vegetable fats and oils Preparation of methyl esters of fatty acids. 3 Principle After neutralization, where necessary, of any free fatty acids, purification of the test portion by column chromatography. Partial enzymatic hydrolysis of the glycerides to yield 2-monoglyce
37、rides. Separation of the monoglycerides by thin-layer chromatography (TLC) and determination of their fatty acid composition by gas chromatography. 4 Reagents Use only reagents of recognized analytical grade and water in accordance with grade 2 of ISO 3696. 4.1 Reagents for the purification of the t
38、est portion 4.1.1 2-Propanol, or ethanol, 95 %(V/V). 4.1.2 Hexane (if available) or light petroleum (boiling range 30 C to 60 C). 4.1.3 2-Propanol, 50 %(V/V), or ethanol, 50 % (V/V). 4.1.4 Sodium hydroxide, 0,5 mol/l solution. 4.1.5 Phenolphthalein solution, 1 g per 100 ml of ethanol, 95 % (V/V). 4.
39、1.6 Activated neutral alumina, for chromatography, Brockmann activity l, recently activated for 2 h at 260 C and kept in a desiccator. 4.1.7 Nitrogen. 4.2 Reagents for hydrolysis of the triglycerides 4.2.1 Diethyl ether, free from peroxides. 4.2.2 Hydrochloric acid, 6 mol/l solution. 4.2.3 Sodium ch
40、olate, 1 g/l solution of enzymatic quality. 4.2.4 Calcium chloride, 220 g/l solution. 4.2.5 Buffer solution, 2-amino-2-(hydroxymethyl)propan-1,3-diol2), 1 mol/l, adjusted to pH 8 with hydrochloric acid (4.2.2) using a pH-meter. Store this solution at between 0 C and 4 C and use within 14 days. 4.2.6
41、 Pancreatic lipase, with an activity of between 8 and 20 units/mg. Store dry in a refrigerator. Before use, bring a portion of the powder to ambient temperature. NOTELipase of suitable activity is available commercially. If preferred, the lipase may be prepared and assayed in accordance with the pro
42、cedure described in Annex A. 4.3 Reagents for the isolation of the 2-monoglycerides 4.3.1 Ethanol, 95 % (V/V). 1) To be published. (Revision of ISO 5509:1978) 2) Alternative names are: tris(hydroxymethyl)methylamine; tris(hydroxymethyl)aminomethane. Licensed Copy: sheffieldun sheffieldun, na, Sun No
43、v 19 14:00:28 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN ISO 6800:1997 2 BSI 04-1999 4.3.2 Hexane (if available) or light petroleum, boiling range 30 C to 60 C. 4.3.3 Acetone. 4.3.4 Silica powder, with binder, for thin-layer chromatography. 4.3.5 Developing solvent, prepared as follows: 4.3.6 29,
44、79-Dichlorofluorescein, indicator solution, 2 g/l in ethanol, rendered slightly alkaline by addition of a drop of 1 mol/l sodium hydroxide per 100 ml of the solution. 4.4 Reagents for the analysis of the 2-monoglycerides by gas chromatography See ISO 5508 and ISO 5509. 5 Apparatus Usual laboratoy eq
45、uipment and, in particular, the following. 5.1 Apparatus for the purification of the test portion 5.1.1 Water bath, thermostatically controlled, and capable of being maintained at 30 C to 40 C. 5.1.2 Glass column, for chromatography, 13 mm internal diameter and 400 mm in length, equipped with a sint
46、ered glass plate and a tap. 5.1.3 Rotary evaporator, with 250 ml flask. 5.1.4 Tubing, for bubbling nitrogen. 5.1.5 Separating funnel, of 500 ml capacity. 5.1.6 Round-bottom flask, of 100 ml capacity. 5.2 Apparatus for the hydrolysis of the triglycerides 5.2.1 Centrifuge. 5.2.2 Centrifuge tube, glass
47、, of 10 ml capacity, with ground stopper. 5.2.3 Vibrating electric shaker, for vigorous agitation of the centrifuge tube. 5.2.4 Water bath, thermostatically controlled, and capable of being maintained at 40 C 0,5 C. 5.2.5 Hypodermic syringe, of 1 ml capacity, with thin needle. 5.2.6 Stopwatch. 5.3 A
48、pparatus for the isolation of the 2-monoglycerides 5.3.1 Developing tank, for thin-layer chromatography, with ground glass lid, suitable for containing glass plates 200 mm 200 mm. 5.3.2 Spreader and rack, for preparation of the plates. 5.3.3 Glass plates, 200 mm 200 mm. 5.3.4 Microsyringe, capable o
49、f dispensing drops of 3 4l to 4 4l. 5.3.5 Apparatus for spraying the indicator solution onto the plates 5.3.6 Microspatula. 5.3.7 Oven, capable of being maintained at 103 C 2 C. 5.3.8 Ultraviolet lamp, for examining chromatographic plates, for example with a wavelength of 254 nm. 5.3.9 Round-bottom flask, of 25 ml capacity, with, air condenser of approximately 1 m length, with ground joint. 5.3.10 Conical flask, of 250 ml capacity, with ground stopper. 5.3.11 Conical flask, of 50 ml capacity (if necessary)