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1、 Reference numbers ISO 3356:2009(E) IDF 63:2009(E) ISO and IDF 2009 INTERNATIONAL STANDARD ISO 3356 IDF 63 Second edition 2009-03-01 Milk Determination of alkaline phosphatase Lait Dtermination de la phosphatase alcaline Copyright International Organization for Standardization Provided by IHS under
2、license with ISO Licensee=HP Monitoring/1111111164 Not for Resale, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3356:2009(E) IDF 63:2009(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobes licensing policy, th
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5、as been taken to ensure that the file is suitable for use by ISO member bodies and IDF national committees. In the unlikely event that a problem relating to it is found, please inform the ISO Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO and IDF 2009 All rights res
6、erved. 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 or IDF at the respective address below. ISO copyright office Interna
7、tional Dairy Federation Case postale 56 CH-1211 Geneva 20 Diamant Building Boulevard Auguste Reyers 80 B-1030 Brussels Tel. + 41 22 749 01 11 Tel. + 32 2 733 98 88 Fax + 41 22 749 09 47 Fax + 32 2 733 04 13 E-mail copyrightiso.org E-mail infofil-idf.org Web www.iso.org Web www.fil-idf.org Published
8、in Switzerland ii ISO and IDF 2009 All rights reserved Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitoring/1111111164 Not for Resale, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3
9、356:2009(E) IDF 63:2009(E) ISO and IDF 2009 All rights reserved iii 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 technica
10、l 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, also take part in the work. ISO collaborates closely wit
11、h the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft Inter
12、national 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. Attention is drawn to the possibility that some of the elements of this document may
13、 be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 3356IDF 63 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 5, Milk and milk products, and the International Dairy Federation (IDF). It is being publish
14、ed jointly by ISO and IDF. This second edition of ISO 3356IDF 63 cancels and replaces the first edition of ISO 3356:1975, which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitoring/1111111164 Not for Resa
15、le, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3356:2009(E) IDF 63:2009(E) iv ISO and IDF 2009 All rights reserved Foreword IDF (the International Dairy Federation) is a non-profit organization representing the dairy sector worldwide. IDF member
16、ship comprises National Committees in every member country as well as regional dairy associations having signed a formal agreement on cooperation with IDF. All members of IDF have the right to be represented at the IDF Standing Committees carrying out the technical work. IDF collaborates with ISO in
17、 the development of standard methods of analysis and sampling for milk and milk products. Draft International Standards adopted by the Action Teams and Standing Committees are circulated to the National Committees for voting. Publication as an International Standard requires approval by at least 50
18、% of IDF National Committees casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IDF shall not be held responsible for identifying any or all such patent rights. ISO 3356|IDF 63 was prepared by Technical Committee ISO/
19、TC 34, Food products, Subcommittee SC 5, Milk and milk products. It is being published jointly by ISO and IDF. All work was carried out by the Joint ISO-IDF Action Team on Heat treatment of the Standing Committee on Minor components and characterization of physical properties under the aegis of its
20、project leader, Mrs. M. Nicolas (FR). This edition of ISO 3356IDF 63 cancels and replaces IDF 63:1971, which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitoring/1111111164 Not for Resale, 04/08/2009 03:0
21、7:35 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISO 3356:2009(E) IDF 63:2009(E) ISO and IDF 2009 All rights reserved 1 Milk Determination of alkaline phosphatase WARNING The use of this International Standard may involve hazardous materials, oper
22、ations and reagents. Persons using this International Standard should be familiar with normal laboratory practice. This International Standard does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety an
23、d health practices and to ensure compliance with any national regulatory conditions. 1 Scope This International Standard specifies a method for the determination of alkaline phosphatase activity in milk. The method applies to alkaline phosphatase activities not less than 1 g of phenol per millilitre
24、. The method is also suitable for the determination of alkaline phosphatase activity in milk powder, buttermilk and buttermilk powder, whey and whey powder. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 alkaline phosphatase activity ALP act
25、ivity alkaline phosphatase activity in milk quantity of phenol liberated by the sample determined according to the procedure specified in this International Standard NOTE The alkaline phosphatase activity is expressed as the quantity of phenol, in micrograms, liberated by 1 ml of the sample or of re
26、constituted sample, under the conditions specified in this International Standard. Other International Standards (e.g. ISO 11816-1IDF 155-16, ISO 22160IDF 2097) express alkaline phosphatase activity in milliunits per litre. The literature gives information on the equivalence of the different units u
27、sed to express the alkaline phosphatase activity. 3 Principle The sample is diluted with a buffer at pH 10,6 and incubated at a temperature of 37 C for 1 h. Under these conditions, any alkaline phosphatase present in the sample liberates phenol from the disodium phenylphosphate added. The phenol lib
28、erated reacts with a quinoneimide (dibromoquinonechlorimide) to produce dibromoindophenol (blue colour) which is measured photometrically at 610 nm. 4 Reagents Use only reagents of recognized analytical grade, unless otherwise specified, and only distilled water or water of equivalent purity. Copyri
29、ght International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitoring/1111111164 Not for Resale, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3356:2009(E) IDF 63:2009(E) 2 ISO and IDF 2009 All rights rese
30、rved 4.1 Barium borate-hydroxide buffer solution Dissolve 25,0 g of barium hydroxide Ba(OH)28H2O, carbonate free, in water in a 500 ml one-mark volumetric flask (5.8). Make up to the mark with water and mix. Dissolve 11,0 g of boric acid (H3BO3) in water in another 500 ml one-mark volumetric flask (
31、5.8). Make up to the mark with water and mix. Warm both solutions to 50 C. Add one to the other and mix by stirring. Cool the solution obtained rapidly to about 20 C. Adjust the pH of the solution, if necessary, to 10,6 0,1 with an additional amount of barium hydroxide solution. Filter the solution
32、through filter paper (5.10). Store the filtered barium borate-hydroxide buffer solution in a tightly stoppered container. Before use, dilute the buffer solution with an equal volume of water. 4.2 Colour development buffer solutions 4.2.1 Colour buffer solution I Dissolve 6,0 g of sodium metaborate (
33、NaBO2) or 12,6 g of NaBO24H2O, and 20,0 g of sodium chloride (NaCl) in water in a 1 000 ml one-mark volumetric flask (5.8). Make up to the mark with water and mix. 4.2.2 Colour buffer solution II Transfer 10 ml of buffer solution I (4.2.1) to a 100 ml one-mark volumetric flask (5.8). Make up to the
34、mark with water and mix. 4.3 Buffer substrate solution 4.3.1 Disodium phenylphosphate dihydrate (Na2C6H5PO42H2O), containing no more than 0,01 % mass fraction phenol. 4.3.2 Dissolve 0,1 g of disodium phenylphosphate dihydrate (4.3.1) in 100 ml of diluted barium borate- hydroxide buffer solution (4.1
35、). 4.4 Zinc-copper precipitant solution Dissolve 3,0 g of zinc sulfate (ZnSO47H2O) and 0,6 g of copper sulfate (CuSO45H2O) in water in a 100 ml one-mark volumetric flask (5.8). Make up to the mark with water and mix. 4.5 2,6-Dibromoquinonechloroimide (BQC) solution, Gibbs reagent. Dissolve 40 mg 1 m
36、g of BQC (C6H2Br2ClNO) in 10 ml of ethanol 96 % volume fraction. Store the solution in a dark coloured bottle at 4 C 2 C. Reject if discoloured or more than 1 month old. 4.6 Copper sulfate solution Dissolve 0,05 g of copper sulfate (CuSO45H2O) in water in a 100 ml one-mark volumetric flask (5.8). Ma
37、ke up to the 100 ml mark with water and mix. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitoring/1111111164 Not for Resale, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3356:2009(E
38、) IDF 63:2009(E) ISO and IDF 2009 All rights reserved 3 4.7 Sodium hydroxide solution, c(NaOH) = 0,5 mol/l. 4.8 Phenol standard solutions 4.8.1 Phenol standard stock solution Transfer a weighed amount of 200 mg 2 mg of anhydrous phenol of purity higher than 99,5 % mass fraction into a 100 ml one-mar
39、k volumetric flask (5.8). Dissolve the phenol in water. Make up to the mark with water and mix. The phenol standard stock solution remains stable at 4 C 2 C for 6 weeks. 4.8.2 Phenol standard working solutions Pipette 10 ml of phenol standard stock solution (4.8.1) into a 100 ml one-mark volumetric
40、flask (5.8). Make up to the mark with water and mix (1 ml contains 200 g of phenol). Use the diluted standard solution to prepare the appropriate phenol standard working solutions, containing 2 g, 5 g, 10 g and 20 g of phenol per millilitre respectively. 5 Apparatus Usual laboratory equipment and, i
41、n particular, the following. 5.1 Analytical balance, capable of weighing to the nearest 1 mg, with a readability of 0,1 mg. 5.2 Photometer, suitable for measuring at a wavelength of 610 nm. 5.3 Water bath, capable of being maintained at 37 C 1 C under thermostatic control. 5.4 Boiling water bath. 5.
42、5 Vortex mixer. 5.6 Pipettes, capacities 0,1 ml, 1 ml, 5 ml and 10 ml, ISO 6481, class A. 5.7 Glass test tubes, of appropriate volumes, with closures made from phenolic-free liners. 5.8 One-mark volumetric flasks, capacities 100 ml, 500 ml and 1000 ml, ISO 10423, class A. 5.9 Glass funnels, diameter
43、s about 60 mm and about 100 mm. 5.10 Filter paper, fast grade, diameters about 110 mm and about 185 mm. 6 Sampling A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage. Sampling is not part of the method specified in
44、this International Standard. A recommended sampling method is given in ISO 707IDF 502. Store the test sample in such a way that deterioration and change in composition are prevented. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=HP Monitorin
45、g/1111111164 Not for Resale, 04/08/2009 03:07:35 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 3356:2009(E) IDF 63:2009(E) 4 ISO and IDF 2009 All rights reserved 7 Preparation of test sample 7.1 Preparation Carefully mix the test sample before use. Usually, it is not
46、necessary to pre-warm the test sample for proper mixing. If pre-warming is necessary, however, the temperature shall under no circumstances exceed 35 C. 7.2 Milk powder, buttermilk powder and whey powder Dissolve 10 g of test sample in 90 ml of water by heating, if necessary. The temperature, howeve
47、r, applied in dissolving the sample completely, shall under no circumstances exceed 35 C. 7.3 Neutralization of acid test samples If the test sample is acidic (pH 7,0), adjust to neutral pH with sodium hydroxide solution (4.7) 8 Procedure 8.1 Preparation of the standard curve 8.1.1 Prepare a range o
48、f standard matching solutions in five glass test tubes (5.7) by pipetting 1 ml of water for the control or blank test tube and 1 ml of each of the four phenol standard working solutions (4.8.2) into each of the remaining four test tubes respectively. The standard test tubes contain 0 g (control or blank), 2 g, 5 g, 10 g and 20 g of phenol respectively. 8.1.2 Add to each test tube (8.1.1) 1 ml of copper sulfate solution (4.6), 5 ml of colour buffer solution II (4.2.2), 3 ml of water