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1、INTERNATIONAL STANDARD 749 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION l MEXAYHAPOAHAII OPl-AHM3AUMII l-IO CTAHAAPTM3AUMM l ORGANIZATION INTERNATIONALE DE NORMALISATION ilseed residues - Determination of total ash Tourteaux de graines oGagineuses - Determination des cendres totales First edition
2、- 1977-10-01 UDC 665.117 : 543.822 Ref. No. IS0 749-1977 (E) Descriptors : oilseeds, oilseed residues, chemical analysis, determination of content, ash. Price based on 2 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Stan
3、dards 1/9972545001 Not for Resale, 04/25/2007 21:46:45 MDTNo reproduction or networking permitted without license from IHS -,-,- FOREWORD IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing In
4、ternational Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, als
5、o take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 749 was developed by Technical Committee ISO/TC 34, Agricultur
6、al food products. It was submitted directly to the IS0 Council, in accordance with clause 6.12.1 of the Directives for the technical work of ISO. It cancels and replaces IS0 Recommendation R 749-1968, which had been approved by the member bodies of the following countries : Australia India Brazil Ir
7、an Bulgaria Ireland Chile Israel Colombia Italy Czechoslovakia Korea, Rep. of France Netherlands Germany Poland Hungary Portugal Romania South Africa, Rep. of Thailand Turkey United Kingdom U.S.S.R. Yugoslavia The member body of the following country had expressed disapproval of the document on tech
8、nical grounds : Canada 0 International Organization for Standardization, 1977 l Printed in Switzerland Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:46:45 MDTNo reproduction
9、 or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD IS0 749-1977 (E) Oilseed residues - Determination of total ash 1 SCOPE AND FIELD OF APPLICATION This International Standard specifies a method for the determination of the total ash from residues (excluding compounded pro
10、ducts) obtained by the extraction of oil from oilseeds by pressure or solvent. 2 REFERENCES I SO 735, Oilseed residues - Determination of ash insoluble in hydrochloric acid. IS0 771, Oilseed residues - Determination of moisture and volatile matter con tent. IS0 5500, Oilseed residues - Sampling. 1 )
11、 3 DEFINITION total ash : The residue obtained after incineration at 550 + I5 “C under the operating conditions specified below. 4 PRINCIPLE Incineration of a test portion at 550 + 15 “C in an electrically heated muffle furnace, until practically constant mass is reached. 5 APPARATUS 5.1 Analytical
12、balance. 5.2 Mechanical mill, easy to clean and allowing the residues to be ground, without heating and without appreci- able change in the moisture, volatile matter and oil content, to particles passing completely through the sieve (5.3). 5.3 Sieve, with apertures of diameter I mm. 5.4 Flat-bottome
13、d incineration dish, of diameter about 60 mm and height not exceeding 25 mm, of platinum, platinum-plated gold, silica or, if not available, porcelain. I 5.5 Electrically and capable of heated muffle furnace, with air circulation being controlled at 650 ? I5 “C. 5.6 Desiccator, containing an efficie
14、nt desiccant. 6 PROCEDURE Make all weighings to the nearest 0,001 g. 6.1 Preparation of the test sample 6.1.1 Take the contract sample obtained in accordance with IS0 5500. 6.1.2 Grind the contract sample, if necessary, in the previously well cleaned mechanical mill (5.2). First, use about one-twent
15、ieth of the sample to complete the cleaning of the mill, and reject these grindings; then grind the rest, collect the grindings, mix carefully and carry out the analysis without delay. 6.2 Test portion 6.2.1 Weigh the incineration dish (5.4), previously heated for I5 min in the furnace (5.5) at 550
16、+ I5 C, and allowed to cool in the desiccator (5.6) to laboratory temperature. 6.2.2 Weigh into the incineration dish about 5 g of the test sample (6.1.2), spread this uniformly over the whole base of the dish and re-weigh. Carry out these operations as quickly as possible, in order to avoid any app
17、reciable change in moisture content. NOTE - If the total ash is not used subsequently for the determi- nation of the residue insoluble in hydrochloric acid (see IS0 735), the test portion may be reduced to 2 g. 6.3 Determination Place the dish containing the test portion on an electric hot-plate or
18、over a gas flame, and heat progressively until the test portion carbonizes, then place in the furnace (5.5), controlled at 550 + I5 “C. Continue heating until a white, light grey or reddish ash is obtained, visibly free from carbon particles (generally at least 2 to 3 h). 1) In preparation. Copyrigh
19、t International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:46:45 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 749-1977 (E) Allow the d ish to cool has reached la
20、bora tory in the desiccat or and weigh when it temper Replace the dish in the furnace and continue heating for 1 h at 550 + 15 “C. Allow the dish to cool and re-weigh, as before. If the difference between the two weighings is less than or equal to 0,002 g, regard the determination as finished. If no
21、t, continue with 1 h periods in the furnace until the difference between two successive weighings is less than or equal to 0,002 g. If the ash is rather blackish after the first incineration of 2 or 3 h, it may be moistened with a few drops of a 200 g/l solution of ammonium nitrate (not in excess so
22、 as to avoid dispersion and sticking together of the ash). After drying in an oven, resume the calcination. If necessary, repeat the operation until incineration is complete. Carry out two determinations on the same test sample. 7 EXPRESSION OF RESULTS 7.1 Method of cakulation and formulae 7.1.1 The
23、 total ash yielded by the sample as received, expressed as a percentage by mass, is equal to m2 -Iy)o x100 “I -mQ m. is the mass, in grams, of the dish; ml is the mass, in grams, of the dish and test portion; m2 is the mass, in grams, of the dish and ash. Take as the result the arithmetic mean of th
24、e two determi- nations, provided that the requirement concerning repeatability (see 7.2) is satisfied. Otherwise, repeat the determination on two other test portions. If this time the difference again exceeds 0,2 g per 100 g of sample, take as the result the arithmetic mean of the four determination
25、s carried out, provided that the maximum difference between the individual results does not exceed 0,5 g per 100 g of sample. Report the result to one decimal place. 9.1.2 If requested, the total ash may be expressed in relation to the dry matter by multiplying the result obtained in accordance with
26、 7.1 .I by 100 100-u where U is the percentage by mass of moisture and volatile matter determined as specified in IS0 771. 7.2 Repeatability The difference between the results of two determinations carried out simultaneously or in rapid succession by the same analyst should not exceed 0,2 g of total
27、 ash per 100 g of sample. 8 TEST REPORT The test report shall show the method used and the result obtained, indicating clearly whether the result is expressed in relation to the product as received or in relation to the dry matter. It shall also mention any operating conditions not specified in this
28、 International Standard, or regarded as optional, as well as any circumstances that may have influenced the result. The report shall include all details required for complete iden tif icatio n of the samp le. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 21:46:45 MDTNo reproduction or networking permitted without license from IHS -,-,-