1、August 2010 Translation by DIN-Sprachendienst.English price group 11No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS
2、 67.060!$j2“1712915www.din.deDDIN EN ISO 2171Cereals, pulses and by-products Determination of ash yield by incineration (ISO 2171:2007)English translation of DIN EN ISO 2171:2010-08Getreide, Hlsenfrchte und Nebenprodukte Bestimmung des Aschegehalts durch Verbrennung (ISO 2171:2007)Englische bersetzu
3、ng von DIN EN ISO 2171:2010-08Crales, lgumineuses et produits drivs Dosage du taux de cendres par incinration (ISO 2171:2007)Traduction anglaise de DIN EN ISO 2171:2010-08SupersedesDIN 10352:1967-09www.beuth.deIn case of doubt, the German-language original shall be considered authoritative.Document
4、comprises 18 pages08.10 DIN EN ISO 2171:2010-08 2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee ISO/TC 34 “Food products” (Secretariat: AFNOR, France), Subcommittee SC 4 “Cereals and pulses” (Secretariat: SAC, China). Based on the res
5、ults of the unique acceptance procedure, ISO 2171:2007 has been adopted by Technical Committee CEN/TC 338 “Cereal and cereal products” (Secretariat: AFNOR, France) as a European Standard. The responsible German body involved in its preparation was the Normenausschuss Lebensmittel und landwirtschaftl
6、iche Produkte (Food and Agricultural Products Standards Committee), Working Committee NA 057-05-06 AA Getreide und Getreideerzeugnisse. The DIN Standards corresponding to the International Standards referred to in this document are as follows: ISO 712 DIN EN ISO 712 ISO 3593 DIN EN ISO 3593 ISO 5725
7、-1 DIN ISO 5725-1 ISO 5725-2 DIN ISO 5725-2 ISO 5725-6 DIN ISO 5725-6 ISO 6644 DIN EN ISO 6644 ISO 13690 DIN EN ISO 13690 Amendments This standard differs from DIN 10352:1967-09 as follows: a) The national standard to be replaced, DIN 10352, refers to the determination of ash of cereal flours. The m
8、ethod is used to determine the flour types. The principle of DIN 10352 is based on the ashing of the sample in a specific dish at a temperature between 900 C and 920 C for 60 min to 90 min. The scope of the present standard has been extended and specifies a method for determining the ash yielded by
9、cereals, pulses and their milled products. Test portions may be incinerated both at 900 C 25 C and 550 C 10 C. b) The matrix area has been expanded. c) The procedure on the basis of two temperature ranges has been given in more detail. d) Diphosphorus pentoxide has been specified as the sole drying
10、agent. e) The material of the ashing dish has been specified. f) Further requirements for the analytical balance have been specified. g) Clause 9 “Procedure” has been rendered more precise. Previous editions DIN 10352: 1967-09 DIN EN ISO 2171:2010-08 3 National Annex NA (informative) Bibliography DI
11、N EN ISO 712, Cereals and cereal products Determination of moisture content Reference method DIN EN ISO 3593, Starch Determination of ash DIN ISO 5725-1, Accuracy (trueness and precision) of measurement methods and results Part 1: General principles and definitions DIN ISO 5725-2, Accuracy (trueness
12、 and precision) of measurement methods and results Part 2: Basic method for the determination of repeatability and reproducibility of a standard measurement method DIN ISO 5725-6, Accuracy (trueness and precision) of measurement methods and results Part 6: Use in practice of accuracy values DIN EN I
13、SO 6644, Flowing cereals and milled cereal products Automatic sampling by mechanical means DIN EN ISO 13690, Cereals, pulses and milled products Sampling of static batches DIN EN ISO 2171:2010-08 4 This page is intentionally blank EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2171 April 2
14、010 ICS 67.060 English Version Cereals, pulses and by-products - Determination of ash yield by incineration (ISO 2171:2007) Crales, lgumineuses et produits drivs - Dosage du taux de cendres par incinration (ISO 2171:2007) Getreide, Hlsenfrchte und Nebenprodukte - Bestimmung des Aschegehalts durch Ve
15、rbrennung (ISO 2171:2007) This European Standard was approved by CEN on 13 March 2010. 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
16、 and bibliographical references concerning such national standards may be obtained on application to the CEN Management Centre 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 respo
17、nsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hu
18、ngary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Cen
19、tre: Avenue Marnix 17, B-1000 Brussels 2010 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 2171:2010: EContents DIN EN ISO 2171:2010-08 EN ISO 2171:2010 (E) 2 Page Foreword3 1 Scope 4 2 Normative references 4 3 Terms and defin
20、itions .4 4 Principle5 5 Reagents.5 6 Apparatus .5 7 Sampling.6 8 Preparation of the test sample .6 9 Procedure .6 9.1 Determination of the moisture content .6 9.2 Preparation of the ashing dishes.6 9.3 Preparation of the test portion .7 9.4 Pre-ashing 7 9.5 Ashing.7 9.6 Number of determinations 7 1
21、0 Expression of results 7 11 Precision.8 11.1 Interlaboratory tests 8 11.2 Repeatability.8 11.3 Reproducibility.8 11.4 Critical difference.9 11.5 Uncertainty .9 12 Test report 9 Annex A (informative) Results of interlaboratory tests.11 Annex B (informative) Practical application of repeatability and
22、 reproducibility limits 13 Bibliography 14 Foreword The text of ISO 2171:2007 has been prepared by Technical Committee ISO/TC 34 “Food products” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 2171:2010 by Technical Committee CEN/TC 338 “Cereal and cerea
23、l products” 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 identical text or by endorsement, at the latest by October 2010, and conflicting national standards shall be withdrawn at the latest by October
24、2010. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organi
25、zations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Port
26、ugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2171:2007 has been approved by CEN as a EN ISO 2171:2010 without any modification. DIN EN ISO 2171:2010-08 EN ISO 2171:2010 (E) 3 1 Scope This International Standard specifies a m
27、ethod for determining the ash yielded by cereals, pulses and their milled products intended for human consumption. The source materials covered are: a) grains of cereals; b) flours and semolinas; c) milled products (bran and high bran content products, sharps); d) mixed cereal flours (mixes); e) cer
28、eal by-products other than milled products; and f) pulses and their by-products. This International Standard is not applicable to starches and starch derivatives (see ISO 3593), to products intended for animal feeding stuffs (see ISO 5984), or to seeds. 2 Normative references The following reference
29、d documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 712, Cereals and cereal products Determination of moisture content R
30、outine reference method ISO 6540, Maize Determination of moisture content (on milled grains and on whole grains) ISO 24557:1), Pulses Determination of moisture content Air-oven method 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 ash incomb
31、ustible residue obtained after incineration according to the method given in this International Standard 1) To be published. DIN EN ISO 2171:2010-08 EN ISO 2171:2010 (E) 4 4 Principle A test portion is incinerated until combustion of organic matter is complete, then the residue obtained is weighed.
32、The residue obtained is flaky after incineration at 550 C and vitrified after incineration at 900 C. In general, products containing salts (e.g. sodium chloride, pyrophosphate) shall be incinerated at (550 10) C. Table 1 summarizes incineration temperatures according to product type. Table 1 Inciner
33、ation temperatures and product type Product type Incineration temperature Flours (550 10) C (900 25) C Semolinas (550 10) C (900 25) C Cereal grains (550 10) C (900 25) C Other milled products (e.g. bran, high bran content products, sharps) (550 10) C Mixed cereal products (mixes) (550 10) C Cereal
34、by-products other than milled products (550 10) C Pulses and their by-products (550 10) C 5 Reagents Unless stated otherwise, use only reagents of recognized analytical quality and distilled or demineralized water or water of equivalent purity. 5.1 Hydrochloric acid, aqueous solution of one part by
35、volume of HCl (35 % volume fraction) and one part by volume of water. 5.2 Purified diphosphorus pentoxide (P4O10). 5.3 Ethanol. 6 Apparatus 6.1 Grinding mill, easy to clean and having as little dead space as possible, and ensuring rapid, uniform grinding. 6.2 Ashing dish, of capacity not less than 2
36、0 ml, rectangular or round shape, flat-bottomed and having a surface area of not less than 12 cm2. Suitable materials for the ashing dish which do not deteriorate under test conditions at the temperature of operation are: a) at 900 C platinum or rhodium; b) at 550 C quartz or silica. In both cases,
37、the material used shall allow compliance with the precision values. The dishes shall be cleaned by complete immersion for at least 1 h in hydrochloric acid (5.1), then rinsed with running water and then with distilled water. DIN EN ISO 2171:2010-08 EN ISO 2171:2010 (E) 5 After rinsing, the dishes sh
38、all be dried in an oven (6.7) at a temperature and for a period sufficient to eliminate water. 6.3 Electrically heated muffle furnace, with adequate ventilation, provided with temperature control system and a refractory coating which is not liable to lose particles at the ashing temperature, and cap
39、able of being maintained at (900 25) C or at (550 10) C. 6.4 Vacuum desiccator, equipped with a perforated aluminium or porcelain plate, and diphosphorus pentoxide (5.2) as drying agent. 6.5 Analytical balance, with an accuracy of 0,01 mg. 6.6 Riffle splitter or cone-shaped divider. 6.7 Oven for dry
40、ing the ashing dishes. 7 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 this International Standard. Recommended sampling methods are given in ISO 6644 a
41、nd ISO 13690. 8 Preparation of the test sample For grains or products containing whole grains, mix and divide the sample in order to obtain a representative quantity compatible with the type of grinding mill (6.1) being used. Grind the sample thus obtained. The other products do not require grinding
42、. 9 Procedure 9.1 Determination of the moisture content Determine beforehand the moisture content of the test sample in accordance with ISO 712 for cereals other than maize or ISO 6540 in the case of maize or ISO 24557 in the case of pulses. Pulses and their derived products should be processed acco
43、rding to ISO 712 with a 90 min drying time and preconditioning if moisture mass fraction is below 7 % or above 13 %. 9.2 Preparation of the ashing dishes For ashing dishes suitable for use at 900 C (6.2), bring the previously cleaned dishes up to the incineration temperature being employed by puttin
44、g them in the muffle furnace (6.3) for 5 min, leave them to cool in the desiccator (6.4), then weigh (6.5) them to within 0,1 mg. For ashing dishes suitable for use at 550 C, place the cleaned dishes in an oven (6.7) for the time required for drying (e.g. 90 min at 130 C). Immediately before use, re
45、move the dishes from the oven and leave them to cool in a desiccator (6.4), then weigh (6.5) them to within 0,1 mg. DIN EN ISO 2171:2010-08 EN ISO 2171:2010 (E) 6 9.3 Preparation of the test portion From the test sample prepared according to Clause 8 and carefully mixed, rapidly weigh (6.5) to withi
46、n 0,1 mg a test portion between 3,9 g and 4,1 g in the case of incineration at 900 C and between 4,9 g and 5,1 g in the case of incineration at 550 C. In the case of low density products, the test portion can be between (2 0,1) g and (3 0,1) g. In the ashing dish, prepared and weighed as described i
47、n 9.2, spread out the product, without packing it, to form a uniform layer. 9.4 Pre-ashing Place the ashing dish and its contents at the entrance of the furnace brought up to the ashing temperature. At 900 C, the products burst into flame spontaneously. At 550 C, it is necessary to ignite them with
48、ethanol (5.3). For pre-ashing at 550 C, it is permissible to put the dishes in the cold furnace and to let the temperature of the furnace rise to the target temperature. 9.5 Ashing Wait until the product has finished burning, then place the dish inside the furnace. Close the furnace door. Continue t
49、he ashing until combustion of the entire product, including the carbon particles contained in the residue, is complete, namely 1 h minimum at 900 C, and 4 h minimum at 550 C. Once the ashing is completed, remove the dish from the furnace and place it in the desiccator (6.4) to cool. In order to maintain the efficiency of the desiccator, do not stack dishes. Due to the hygroscopic nature of the ash, as soon as the dish has reached ambient tempe
