1、BRITISH STANDARD CONFIRMED NOVEMBER 1997 BS 4325-2: 1978 Methods for Analysis of oilseed residues Part 2: Determination of total ash UDC 633.85:665.3.002.68:543.822BS4325-2:1978 This British Standard, having been prepared under the directionof the Oil and Fats Standards Committee was published under
2、 the authority ofthe Executive Board on 29 December1978 BSI 10-1999 First published July 1968 First revision December 1978 The following BSI references relate to the work on this standard: Committee reference OFC/24 Draft for approval 78/50359 ISBN 0 580 10472 9 Cooperating organizations The Oils an
3、d Fats Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following Government department and scientific and industrial organizations: Chemical Industries Association Chemical Society, Analytical Division* Department of Industry, Labor
4、atory of the Government Chemist* Greater London Council Lard Association Margarine and Shortening Manufacturers Association* Overseas Development Administration Tropical Products Institute* Royal Institute of Public Health and Hygiene Seed Crushers and Oil Processors Association* Soap and Detergent
5、Industry Association* United Kingdom Renderers Association Ltd. The organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Fatty Acid Distillers British F
6、ood Manufacturing Industries Research Association British Resin Manufacturers Association Co-operative Wholesale Society Ltd. Federation of Gelatine and Glue Manufacturers Limited Federation of Oils, Seeds and Fats Association Ltd. Ministry of Agriculture Fisheries and Food National Linseed Oil Proc
7、essors Association Oil and Colour Chemists Association Rubber Growers Association Society of Chemical Industry United Kingdom Glycerine Producers Association Amendments issued since publication Amd. No. Date of issue CommentsBS4325-2:1978 BSI 10-1999 i Contents Page Cooperating organizations Inside
8、front cover Foreword ii 1 Scope and field of application 1 2 References 1 3 Definition 1 4 Principle 1 5 Apparatus 1 6 Procedure 1 7 Expression of results 2 8 Test report 2 Publications referred to Inside back coverBS4325-2:1978 ii BSI 10-1999 Foreword This Part of BS4325, which was prepared under t
9、he direction of the Oils and Fats Standards Committee, constitutes the first revision of BS4325-2:1968. It is identical with ISO749 “Oilseed residues Determination of total ash”, except for changes in clauses1, 2, 6.1.1, 6.2.2 (note), 7.1.2 and 8. In clauses1 and8 the words “International Standard”
10、have been replaced by “British Standard”. Clause2 and the sampling instructions given in6.1.1 have been altered because the ISO text refers to a sampling standard which is not yet available. Also in clause2, and in6.2.2 (note) and7.1.2, the references to International Standards have been replaced by
11、 references to British Standards. The text of the International Standard has been used as the basis of this British Standard; therefore certain conventions are not identical with those normally used in British Standards; attention is especially drawn to the following. The comma has been used as a de
12、cimal marker. In British Standards it is current practice to use a full point on the baseline as the decimal marker. IMPORTANT NOTE. Attention is drawn to Statutory Instrument1973 No1521 (Agriculture. The Fertilisers and Feeding Stuffs Regulations1973) and to Statutory Instrument1976 No840 (Agricult
13、ure. The Fertilisers and Feeding Stuffs (Amendment) Regulations 1976), which control the sale of oilseed residues and compound cakes or meals intended for animal feeding purposes in the UnitedKingdom and prescribe methods for determining specified analytical characteristics. Where differences exist
14、between these methods and those given in this British Standard the latter may be used only for purposes which do not fall within the scope of the Statutory Instruments. Additional information. A sieve complying with the requirements of BS410 “Specification for test sieves” will satisfy the requireme
15、nt in5.3. A British Standard does not purport 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
16、comprises a front cover, an inside front cover, pagesi andii, pages1 and2, an inside back cover and a back 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.BS4325-2:1978 BSI 10
17、-1999 1 NOTEThose parts of the text which differ from ISO 749 are indicated by a vertical line in the margin. Otherwise this standard is identical with ISO749. 1 Scope and field of application This British Standard specifies a method for the determination of the total ash from residues (excluding co
18、mpounded products) obtained by the extraction of oil from oilseeds by pressure or solvent. 2 References The titles of the publications referred to in this standard are given on the inside back cover. NOTEAn International Standard, ISO5500 “Oilseed residues Sampling”, is in course of preparation. It
19、is intended to publish a British Standard dealing with sampling of oilseed residues at a later date. Until such time, preparation of the contract sample should be in accordance with6.1.1. 3 Definition total ash the residue obtained after incineration at550 15 C under the operating conditions specifi
20、ed below 4 Principle Incineration of a test portion at550 15 C in an electrically heated muffle furnace, until practically constant mass is reached. 5 Apparatus 5.1 Analytical balance 5.2 Mechanical mill, easy to clean and allowing the residues to be ground, without heating and without appreciable c
21、hange in the moisture, volatile matter and oil content, to particles passing completely through the sieve (5.3). 5.3 Sieve, with apertures of diameter1mm. 5.4 Flat-bottomed incineration dish, of diameter about60mm and height not exceeding25mm, of platinum, platinum-plated gold, silica or, if not ava
22、ilable, porcelain. 5.5 Electrically heated muffle furnace, with air circulation and capable of being controlled at550 15 C. 5.6 Desiccator, containing an efficient desiccant. 6 Procedure Make all weighings to the nearest0,001g. 6.1 Preparation of the test sample 6.1.1 It is essential to ensure that
23、the contract sample is fully representative of the material under test. (See also note to clause2.) 6.1.2 Grind the contract sample, if necessary, in the previously well cleaned mechanical mill (5.2). First, use about one-twentieth of the sample to complete the cleaning of the mill, and reject these
24、 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 for15min in the furnace (5.5) at550 15 C, and allowed to cool in the desiccator(5.6) to laboratory temperature.
25、6.2.2 Weigh into the incineration dish about5g 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 appreciable change in moisture content. NOTEIf the total ash is not used subsequentl
26、y for the determination of the residue insoluble in hydrochloric acid (seeBS4325-3), the test portion may be reduced to2g. 6.3 Determination Place the dish containing the test portion on an electric hot-plate or over a gas flame, and heat progressively until the test portion carbonizes, then place i
27、n the furnace (5.5), controlled at550 15 C. Continue heating until a white, light grey or reddish ash is obtained, visibly free from carbon particles (generally at least2 to3h). Allow the dish to cool in the desiccator and weigh when it has reached laboratory temperature. Replace the dish in the fur
28、nace and continue heating for1h at550 15 C. Allow the dish to cool and re-weigh, as before. If the difference between the two weighings is less than or equal to0,002g, regard the determination as finished. If not, continue with1h periods in the furnace until the difference between two successive wei
29、ghings is less than or equal to0,002g. If the ash is rather blackish after the first incineration of2 or3h, it may be moistened with a few drops of a200g/l solution of ammonium nitrate (not in excess so as to avoid dispersion and sticking together of the ash). After drying in an oven, resume the cal
30、cination. If necessary, repeat the operation until incineration is complete. Carry out two determinations on the same test sample.BS4325-2:1978 2 BSI 10-1999 7 Expression of results 7.1 Method of calculation and formulae 7.1.1 The total ash yielded by the sample as received, expressed as a percentag
31、e by mass, is equal to where Take as the result the arithmetic mean of the two determinations, provided that the requirement concerning repeatability (see7.2) is satisfied. Otherwise, repeat the determination on two other test portions. If this time the difference again exceeds0,2g per100g of sample
32、, take as the result the arithmetic mean of the four determinations carried out, provided that the maximum difference between the individual results does not exceed0,5g per100g of sample. Report the result to one decimal place. 7.1.2 If requested, the total ash may be expressed in relation to the dr
33、y matter by multiplying the result obtained in accordance with7.1.1 by where U is the percentage by mass of moisture and volatile matter determined as specified in BS4325-1. 7.2 Repeatability The difference between the results of two determinations carried out simultaneously or in rapid succession b
34、y the same analyst should not exceed0,2g of total ash per100g 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
35、 any operating conditions not specified in this British 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 identification of the sample. m 0 is the mass, in grams, of the dish; m 1 is the mas
36、s, in grams, of the dish and test portion; m 2 is the mass, in grams, of the dish and ash. m 2 m 0 m 1 m 0 -100 100 100U -BS4325-2:1978 BSI 10-1999 Publications referred to BS 4325, Methods for the analysis of oilseed residues. BS 4325-1, Determination of moisture and volatile matter content (ISO771
37、). BS 4325-3, Determination of ash insoluble in hydrochloric acid (ISO735). BS 4325-2: 1978 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 t
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