BS EN ISO 1666-1998 Starch - Determination of moisture content - Oven-drying method《淀粉 水含量的测定 烘箱干燥法》.pdf

1、BRITISH STANDARD BS EN ISO 1666:1998 Starch Determination of moisture content Oven-drying method The European Standard EN ISO 1666:1997 has the status of a British Standard ICS 67.180.20BSEN ISO 1666:1998 This British Standard, having been prepared under the direction of the Consumer Products and Se

2、rvices Sector Board, was published under theauthority of the StandardsBoard and comes intoeffect on 15 January 1998 BSI 04-1999 ISBN 0 580 29098 0 National foreword This British Standard is the English language version of EN ISO 1666:1997. It is identical with ISO 1666:1997. It supersedes BS EN ISO

3、1666:1994 which is withdrawn. This British Standard has been produced to fulfil BSIs obligation to publish all approved European Standards but, because of the absence of interest in the UK in the subject concerned, there has been no UK participation in the preparation of EN ISO 1666. Any queries rel

4、ating to the EN should be directed to BSI, quoting the reference “AW/100”. Cross-references Attention is drawn to the fact that CEN and CENELEC Standards normally include an annex which lists normative references to international publications with their corresponding European publications. The Briti

5、sh Standards which implement these international or European publications may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purp

6、ort 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 confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front c

7、over, pages i and ii, theEN ISO title page, page 2, the ISO title page, page ii, pages 1 to 3 andaback cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Amendments issued since

8、 publication Amd. No. Date CommentsBSENISO1666:1998 BSI 04-1999 i Contents Page National foreword Inside front cover Foreword 2 Foreword ii Text of EN ISO 1666 1ii blankEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 1666 November 1997 ICS 67.180.20 Supersedes EN ISO 1666:1994 Descriptors:

9、See ISO document English version Starch Determination of moisture content Oven-drying method (ISO 1666:1996) Amidon et fcule Dtermination de lhumidit Mthode par schage ltuve (ISO 1666:1996) Strke Bestimmung des Feuchtegehaltes Wrmeschrankverfahren (ISO 1666:1996) This European Standard was approved

10、by CEN on 30 October 1997. 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 national sta

11、ndards 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 notified t

12、o 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 and Uni

13、ted 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. EN ISO

14、 1666:1997 EENISO1666:1997 BSI 04-1999 2 Foreword The text of the International Standard from Technical Committee ISO/TC 93 “Starch (including derivatives and by-products)” of the International Organization for Standardization (ISO) has been taken over as an European Standard by Technical Committee

15、CEN/CS. This European Standard replaces ENISO1666:1994. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by May 1998, and conflicting national standards shall be withdrawn at the latest by May 1998. A

16、ccording to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, CzechRepublic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portu

17、gal, Spain, Sweden, Switzerland and the UnitedKingdom. Endorsement notice The text of the International Standard ISO1666:1996 has been approved by CEN as a European Standard without any modification. Contents Page Foreword 2 1 Scope 1 2 Definition 1 3 Principal 1 4 Apparatus 1 5 Test sample 1 6 Proc

18、edure 1 7 Calculation 1 8 Precision 2 9 Test report 2 Annex A (informative) Results of interlaboratory test 3 Table1 2 Table A.1 3ENISO1666:1997 ii BSI 04-1999 Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies)

19、. 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 committee. International organizations, governmental and non

20、-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. Draft International Standards adopted by the technical committees are circulated to the member bodies

21、for voting. Publication as an International Standard requires approval by at least 75% of the member bodies casting a vote. International Standard ISO1666 was prepared by Technical Committee ISO/TC93, Starch (including derivatives and by-products). This second edition cancels and replaces the first

22、edition (ISO1666:1973), which has been technically revised. Annex A of this International Standard is for information only. Descriptors: Carbohydrates, starches, tests, determination of content, water, moisture content.ENISO1666:1997 BSI 04-1999 1 1 Scope This International Standard specifies a meth

23、od for the determination of the moisture content of starch using oven-drying at 130 C under atmospheric pressure. The method is applicable to native or modified starch in the dry form. In special circumstances, for example if the starch contains substances which are unstable at 130 C, the method is

24、not applicable. 2 Definition For the purposes of this International Standard, the following definition applies. 2.1 moisture content of starch loss in mass of the material under the test conditions specified in this International Standard, expressed as a percentage by mass 3 Principle Dehydration of

25、 the test portion in an electrically heated drying oven at 130 C to 133 C, under atmospheric pressure, for a period of 1h 30min. 4 Apparatus Usual laboratory apparatus and, in particular, the following. 4.1 Analytical balance, capable of weighing to the nearest 0,001g. 4.2 Dish, made of a metal unaf

26、fected by starch under the test conditions (e.g. aluminium), with a suitable tight-fitting lid, the effective surface being such that the test portion when evenly distributed has a thickness corresponding to not more than0,3g/cm 2 . Suitable dimensions are 55mm to65mm diameter, 15mm to 30mm height a

27、nd0,5mm wall thickness. 4.3 Constant-temperature oven, electrically heated, with suitable air circulation, controlled in such a way that the temperature of the air surrounding the test portions and of the shelves carrying the test portions is within the range 130 C to 133 C under normal conditions.

28、The heat capacity shall be such that, when the oven is initially adjusted to 131 C, it can regain this temperature in less than 30 min after insertion of the maximum number of test portions that can be dried simultaneously. 4.4 Desiccator, provided with a thick perforated metal plate for rapid cooli

29、ng of the dishes, and containing an effective drying agent. 5 Test sample The test sample shall be free from any hard and lumpy material. It should be received in an airtight and moisture-tight container. After withdrawing the test portions, the remainder of the sample shall be stored in the same co

30、ntainer for further tests if required. It shall be homogenized before use. 6 Procedure 6.1 Test portion Carry out weighings to the nearest 0,001 g. After drying at 130 C and cooling in the desiccatortor(4.4), weigh the dish (4.2) and its lid (m 0 ). Using the balance (4.1), weigh 5 g 0,25 g of the w

31、ell-mixed sample and transfer it to the dish with the minimum exposure to the atmosphere. Replace the lid and weigh immediately to determine the mass of the test portion and dish (m 1 ). Distribute the test portion in a uniform layer over the bottom of the dish. 6.2 Determination Place the open dish

32、 containing the test portion in the oven (4.3) preheated to 130 C, allowing the lid to lean against the dish, and dry at 130 C to133C for 1 h 30 min, calculated from the moment when the oven temperature again reaches130 C. After this period, rapidly cover the dish and put it in the desiccator. Never

33、 superimpose dishes in the desiccator. Allow the test portion to cool to room temperature in the desiccator (4.4) for 30 min to 45 min. When the dish has cooled to room temperature, weigh it and the lid (m 2 ) within 2 min of its removal from the desiccator. Carry out at least two determinations on

34、the same test sample. 7 Calculation The moisture content, expressed as a percentage by mass, is given by the formula where m 0 is the mass, in grams, of the dried empty dish and lid; m 1 is the mass, in grams, of the dish with the test portion and lid before drying; m 2 is the mass, in grams, of the

35、 dish with the test portion and lid after drying. m 1 m 2 () 100 % m 1 m 0 - ENISO1666:1997 2 BSI 04-1999 Take as the result the arithmetic mean of the two determinations, if their absolute difference does not exceed the value given for the repeatability limit in8.1. Report the result to the first d

36、ecimal place. 8 Precision Details of an interlaboratory test on the precision of the method are summarized in Annex A. The values derived from the interlaboratory test may not be applicable to analyte concentration ranges and matrices other than those given. 8.1 Repeatability The absolute difference

37、 between two independent single test results, obtained using the same method on identical test material in the same laboratory by the same operator using the sample equipment within a short interval of time, should not be greater than the repeatability limit r given in Table 1, in more than 5% of ca

38、ses. 8.2 Reproducibility The absolute difference between two single test results, obtained using the same method on identical test material in different laboratories with different operators using different equipment, should not be greater than the reproducibility limit R given in Table 1, in more t

39、han 5% of cases. Table 1 9 Test report The test report shall specify: the method used; the test result obtained; and if the repeatability has been checked, the final quoted result obtained. It shall also mention all operating details not specified in this International Standard, or regarded as optio

40、nal, together with details of any incidents which may have influenced the test result. The test report shall include all information necessary for the complete identification of the sample. Starch type Repeatability limit, r % (m/m) Reproducibility, R % (m/m) Wheat Maize High amylose content Modifie

41、d waxy maize Cationic maize Pea Potato 0,3 0,2 0,2 0,2 0,1 0,3 0,1 0,4 0,4 0,4 0,4 0,5 0,5 0,3ENISO1666:1997 BSI 04-1999 3 Annex A (informative) Results of interlaboratory test An interlaboratory test was conducted in 1989, with seven laboratories participating on seven samples of starches, includin

42、g two modified starches. The results are given in Table A.1. Table A.1 Parameter Type of starch Wheat Maize High amylose content Modified waxy maize Cationic maize Pea Potato No. of laboratories retained after eliminating outliers No. of outliers (laboratories) No. of accepted results Mean value % (

43、m/m) Repeatability standard deviation, s r% (m/m) Repeatability coefficient of variation (%) Repeatability limit, r = 2,8 s r%(m/m) Reproducibility standard deviation, s R% (m/m) Reproducibility coefficient of variation (%) Reproducibility limit, R = 2,8 s R% (m/m) 7 0 14 11,9 0,97 0,812 0,274 0,134

44、 1,12 0,379 7 0 14 13,3 0,049 6 0,373 0,140 0,133 1,00 0,376 7 0 14 12,4 0,059 4 0,480 0,168 0,114 0,928 0,324 7 0 14 13,4 0,067 8 0,506 0,192 0,123 0,916 0,348 7 0 14 11,9 0,035 2 0,296 0,099 5 0,157 1,32 0,443 7 0 14 8,64 0,087 9 1,02 0,249 0,172 1,99 0,486 6 1 12 18,1 0,028 9 0,159 0,081 7 0,087

45、9 0,486 0,249BS EN ISO 1666:1998 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter

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