BS EN ISO 3593-1994 Starch - Determination of ash《淀粉 灰分测定》.pdf

1、BRITISH STANDARD BS EN ISO 3593:1994 Starch Determination of ash The European Standard EN ISO3593:1994 has the status of a BritishStandard UDC664.2:543.822BSENISO3593:1994 This BritishStandard was published under the authority ofthe Standards Board and comesinto effect on 15 December1994 BSI01-2000

2、The following BSI references relate to the work on this standard: Draft announced in BSINews,March1993 ISBN 0 580 23181 X Cooperating organizations The European Committee for Standardization (CEN), under whose supervision this European Standard was prepared, comprises the national standards organiza

3、tions of the following countries: Austria Oesterreichisches Normungsinstitut Belgium Institut belge de normalisation Denmark Dansk Standard Finland Suomen Standardisoimisliito, r.y. France Association franaise de normalisation Germany Deutsches Institut fr Normung e.V. Greece Hellenic Organization f

4、or Standardization Iceland Technological Institute of Iceland Ireland National Standards Authority of Ireland Italy Ente Nazionale Italiano di Unificazione Luxembourg Inspection du Travail et des Mines Netherlands Nederlands Normalisatie-instituut Norway Norges Standardiseringsforbund Portugal Insti

5、tuto Portugus da Qualidade Spain Asociacin Espaola de Normalizacin y Certificacin Sweden Standardiseringskommissionen i Sverige Switzerland Association suisse de normalisation UnitedKingdom BritishStandards Institution Amendments issued since publication Amd. No. Date CommentsBSENISO3593:1994 BSI 01

6、-2000 i Contents Page Cooperating organizations Inside front cover National foreword ii Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 Reference 3 3 Definition 3 4 Principle 3 5 Apparatus 3 6 Procedure 3 7 Expression of results 4 8 Test report 4 National annex NA (informative) Cros

7、s-reference Inside back coverBSENISO3593:1994 ii BSI 01-2000 National foreword This BritishStandard has been prepared under the direction of the BSI Standards Board and is the English language version of EN ISO3593:1994 Starch Determination of ash, published by the European Committee for Standardiza

8、tion (CEN). It is identical with ISO3593:1981 Starch Determination of ash, published by the International Organization for Standardization (ISO). This BritishStandard has been produced to fulfil BSIs obligation to publish all approved European Standards but, because of the absence of interest in the

9、 UK in the subject concerned, there has been no UK participation in the preparation of EN ISO3593. Any queries relating to the EN should be directed to BSI. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their

10、 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 cover, pagesi andii, theEN ISO title page, pages2 to4, an inside back cover and a back cover. This standard has

11、been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO3593 August1994 UDC664.2:543.822 Descriptors: Starch, determination of ash English version Starc

12、h Determination of ash (ISO3593:1981) Amidons et fcules Dtermination des cendres (ISO3593:1981) Strke Bestimmung der Asche (ISO3593:1981) This European Standard was approved by CEN on1994-08-22. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions

13、for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three offici

14、al 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 to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Be

15、lgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and UnitedKingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Sta

16、ssart 36, B-1050 Brussels 1994 Copyright reserved to CEN members Ref. No. EN ISO3593:1994 EENISO3593:1994 BSI 01-2000 2 Foreword The text of the International Standard ISO3593:1981, prepared by ISO/TC93, Starch, was submitted to the formal vote and was approved by CEN as EN ISO3593:1994 on1994-08-22

17、 without any modifications. 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 February1995, and conflicting national standards shall be withdrawn at the latest by February1995. According to the CEN/

18、CENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland, UnitedKingdom.ENISO3593:1994 BSI 01-2000 3

19、 0 Introduction Native starches contain naturally small amounts of mineral substances. Converted starches may additionally contain variable amounts of added mineral substances. This International Standard specifies a procedure for the conventional evaluation of both of these amounts together. 1 Scop

20、e and field of application This International Standard specifies a method for the determination of the ash yielded by starches. The method is applicable to native starches and to modified starches yielding not more than2% of ash. It does not apply to hydrolysis products nor to oxidized starches, nor

21、 to other products containing more than0,2% of chloride expressed as sodium chloride. In the other cases, use the method specified in ISO5809. 1) 2 Reference ISO1666, Starch Determination of moisture content Oven-drying methods. 3 Definition For the purpose of this International Standard, the follow

22、ing definition applies: ash the residue obtained after incineration of the product under the conditions specified in this International Standard the ash is expressed as a percentage by mass either of the product as received or on the dry basis 4 Principle Incineration of a test portion, at a tempera

23、ture of900 C, until complete disappearance of the carbon in the residue. 5 Apparatus Ordinary laboratory apparatus, and in particular: 5.1 Ashing dishes, of platinum or of any other material unaffected under the test conditions, with a flat base, a capacity of about40ml and a minimum usable surface

24、area of15cm 2 . 5.2 Desiccator, provided with a thick perforated metal plate, and containing an efficient desiccant such as phosphorus(V) oxide, silica gel impregnated with cobalt chloride indicator, or granular anhydrous calcium sulphate similarly treated. 5.3 Electric furnace with ventilation, inc

25、luding a device for control and adjustment of temperature to provide for incineration at a temperature of900 25 C. 5.4 Analytical balance 5.5 Electric hot-plate or bunsen burner. 6 Procedure 6.1 Preparation of the dish Clean the ashing dish(5.1), whether new or used, for example with boiling dilute

26、hydrochloric acid, and rinse copiously with tap water and then with distilled water. Place the dish in the furnace(5.3) and heat for30min at900 25 C. Allow to cool to room temperature in the desiccator(5.2) and then weigh to the nearest0,0001g. 6.2 Test portion Weigh rapidly, to the nearest0,001g,2

27、to10g of the product 2)according to the expected yield of ash. Distribute the material without compression in the dish. 6.3 Pre-incineration Heat the dish and its contents carefully, for example by placing it at the entrance of the furnace or on an electric hot-plate or a bunsen burner(5.5) until th

28、e test portion is completely carbonized. Ignite the volatile substances produced, in order to avoid autoignition, which could give rise to a loss of product by projection from the dish. 6.4 Incineration As soon as the flame has gone out, place the dish in the furnace, raise the temperature to900 25

29、C and maintain at this temperature until the residual carbon has completely disappeared. A period of1h is normally sufficient. Place the dish and the residue in the desiccator, allow to cool to room temperature and weigh to the nearest0,0001g. Do not put more than four dishes at once in the desiccat

30、or. 6.5 Number of determinations Carry out at least two determinations on the same sample. 1) ISO5809, Starch, including derivatives and by-products Determination of sulphated ash (at present at the stage of draft). 2) It is generally convenient to take at least5g for potato, wheat and rice starches

31、 and10g for maize or manioc starches.ENISO3593:1994 4 BSI 01-2000 7 Expression of results 7.1 Method of calculation and formulae The ash yield, expressed as a percentage by mass of the sample as received, is given by the formula The ash yield, expressed as a percentage by mass of the sample on the d

32、ry basis, is given by the formula where m 0 is the mass, in grams, of the test portion; m 1 is the mass, in grams, of the residue after incineration; H is the moisture content of the product, determined by the method specified in ISO1666. Take as the result the arithmetic mean of the values obtained

33、 in two determinations, provided that the requirement for repeatability(see7.2) is fulfilled. Express the result to the second decimal place. 7.2 Repeatability The difference between the values obtained in two determinations, carried out simultaneously or in rapid succession by the same analyst on t

34、he same sample, shall not exceed0,02 as an absolute value when the ash yield is less than or equal to1%, and shall not exceed2% of the mean when the ash yield is greater than1%. If the difference exceeds these limits, two further determinations shall be carried out. 8 Test report The test report sha

35、ll indicate the method used and the results obtained. In addition, it shall mention all operating conditions not specified in this International Standard, or regarded as optional, as well as any circumstances that may have influenced the results. The test report shall include all details necessary f

36、or the complete identification of the sample. m 1 100 m 0 - m 1 100 m 0 - 100 100H - BSENISO3593:1994 BSI 01-2000 National annex NA (informative) Cross-reference Publication referred to Corresponding BritishStandard ISO1666:1973 BS EN ISO1666:1994 Starch Determination of moisture content Ovendrying

37、methodsBS EN ISO 3593:1994 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. Revi

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