ISO 663-2007

Reference numberISO 663:2007(E)©ISO 2007INTERNATIONAL STANDARD ISO663Fourth edition2007-03-01Animal and vegetable fats and oils — Determination of insoluble impurities content Corps gras d origines animale et végétale — Détermination de la teneur en impuretés insolubles Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe s licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe s licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. 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ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii © ISO 2007 – All rights reservedCopyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) © ISO 2007 – All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). 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-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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 663 was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 11, Animal and vegetable fats and oils. This fourth edition cancels and replaces the third edition (ISO 663:2000), which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---INTERNATIONAL STANDARD ISO 663:2007(E)© ISO 2007 – All rights reserved 1Animal and vegetable fats and oils — Determination of insoluble impurities content 1 Scope This International Standard specifies a method for the determination of the insoluble impurities content of animal and vegetable fats and oils. If it is not desired to include soaps (particularly calcium soaps) or oxidized fatty acids in the insoluble impurities content, it is necessary to use a different solvent and procedure. In this case, an agreement is to be reached between the parties concerned. 2 Normative reference The following referenced 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 661, Animal and vegetable fats and oils — Preparation of test sample 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 insoluble impurities content quantity of dirt and other foreign matter insoluble in n-hexane or light petroleum under the conditions specified in this International Standard NOTE 1 The content is expressed as a percentage by mass. NOTE 2 These impurities include mechanical impurities, mineral substances, carbohydrates, nitrogenous substances, various resins, calcium soaps, oxidized fatty acids, fatty acid lactones, and (in part) alkali soaps, hydroxy-fatty acids and their glycerides. 4 Principle A test portion is treated with an excess of n-hexane or light petroleum, then the solution obtained is filtered. The filter and residue are washed with the same solvent, then dried at 103 °C and weighed. 5 Reagents WARNING — Attention is drawn to the regulations which specify the handling of dangerous substances. Technical, organizational and personal safety measures shall be followed. Use only reagents of recognized analytical grade. Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) 2 © ISO 2007 – All rights reserved5.1 n-Hexane, or in the absence of this, light petroleum, having a distillation range between 30 °C and 60 °C and having a bromine value of less than 1. For either solvent, the residue on complete evaporation shall not exceed 0,002 g per 100 ml. 5.2 Kieselgur, purified, calcinated, with loss in mass at 900 °C (red heat) of less than 0,2 % by mass. 6 Apparatus Usual laboratory apparatus and, in particular, the following. 6.1 Analytical balance, with an accuracy of ± 0,001 g. 6.2 Electric drying oven, capable of operating at 103 °C ± 2 °C. 6.3 Conical flask, of 250 ml capacity, with ground glass stopper. 6.4 Desiccator, containing an efficient desiccant. 6.5 Ashless filter paper (maximum ash content 0,01 %, by mass); retention value of 98 %, by mass, for particles of size greater than 2,5 µm1), or an equivalent glass-fibre filter, of diameter 120 mm, together with a metal (preferably aluminium) or glass vessel with a well-fitting lid. These are alternatives to the filter (6.6) for all products except acid oils. 6.6 Filter crucible, glass, of grade P16 (pore size 10 µm to 16 µm), diameter 40 mm, of capacity 50 ml, together with a suction bottle. This is an alternative to 6.5 for all products including acid oils. 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. A recommended sampling method is given in ISO 5555. 8 Preparation of test sample Prepare the test sample in accordance with ISO 661. 9 Procedure 9.1 Test portion Weigh, to the nearest 0,01 g, approximately 20 g of the test sample (Clause 8) into a conical flask (6.3). 1)Whatman 42 (2,5 µm) filter paper or Whatman GF/D glass-fibre filter are examples of suitable products available commercially. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of these products. Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) © ISO 2007 – All rights reserved 39.2 Determination 9.2.1 Dry the filter paper and the vessel (6.5) with its lid, or the filter crucible (6.6), in the oven (6.2) set at 103 °C. Allow to cool in the desiccator (6.4) then weigh to the nearest 0,001 g. For acid oils, prepare the crucible as described in 9.2.7 and continue as in 9.2.2. 9.2.2 Add 200 ml of n-hexane or light petroleum (5.1) to the flask containing the test portion (9.1). Stopper the flask and shake. For castor oil, the quantity of solvent may be increased to facilitate the operation, and this may necessitate the use of a larger flask. Leave to stand at about 20 °C for about 30 min. 9.2.3 Filter through the filter paper in a suitable funnel, or through the filter crucible, using suction if necessary. Rinse the flask to ensure that all impurities are washed into the filter/crucible. Wash the filter paper or filter crucible by pouring through it small amounts of the same solvent as used in 9.2.2, but no more than is necessary for the final filtrate to be free from fat or oil. Warm the solvent, if necessary, to a maximum temperature of 60 °C in order to dissolve any solidified fats retained on the filter. 9.2.4 If a filter paper is used, remove it from the funnel and place it in the vessel. Allow most of the solvent remaining in the filter paper to evaporate in air, and complete the evaporation in the oven set at 103 °C. Then remove from the oven, close the vessel with its lid, allow to cool in the desiccator (6.4) and weigh to the nearest 0,001 g. 9.2.5 If a filter crucible is used, allow most of the solvent remaining in it to evaporate in air under a fume hood, and complete the evaporation in the oven set at 103 °C. Then remove from the oven, allow to cool in the desiccator (6.4) and weigh to the nearest 0,001 g. 9.2.6 If it is desired to determine the content of organic impurities, the use of a previously dried and weighed, ashless filter paper is necessary. In this case, the filter paper containing the insoluble impurities shall be ignited and the mass of ash obtained subtracted from the mass of insoluble impurities. The organic impurities content, expressed as a percentage by mass, is then calculated by multiplying this difference in mass by 100/m0, where m0is the mass, in grams, of the test portion. 9.2.7 If analysing acid oils, coat the glass filter crucible with kieselgur (5.2) as follows. In a 100 ml glass beaker, prepare a slurry consisting of 2 g of kieselgur and approximately 30 ml of light petroleum (5.1). Pour the mixture into the filter crucible under reduced pressure in order to obtain a layer of kieselgur on the glass filter. Dry the prepared glass filter crucible for 1 h in the oven (6.2) set at 103 °C. Allow to cool in the desiccator (6.4) and weigh to the nearest 0,001 g. Carry out two determinations on test portions taken from the same test sample (Clause 8). Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) 4 © ISO 2007 – All rights reserved10 Expression of results The insoluble impurities content, w, expressed as a percentage by mass, is equal to 210100 %mmwm-=¥ where m0 is the mass of the test portion (9.1), in grams; m1is the mass of the vessel with its lid and filter paper, or of the filter crucible (see 9.2.1), in grams; m2is the mass of the vessel with its lid and filter paper containing the dry residue (see 9.2.4), or of the filter crucible and dry residue (see 9.2.5), in grams. Report the result to the second decimal place. 11 Precision 11.1 Interlaboratory tests Details of interlaboratory tests on the precision of the method are summarized in Annex A. The values derived from these interlaboratory tests may not be applicable to concentration ranges and matrices other than those given. 11.2 Repeatability The absolute difference 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 same equipment within a short interval of time, will in not more than 5 % of the cases exceed the value of the repeatability limit, r, given in Table A.1. 11.3 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, will in not more than 5 % of cases exceed the value of the reproducibility limit, R, given in Table A.1. 12 Test report The test report shall specify: a) all information necessary for the complete identification of the sample; b) the sampling method used, if known; c) the test method used, with reference to this International Standard; d) the solvent used; e) any operating details not specified in this International Standard, or regarded as optional, together with details of any incidents which may have influenced the test results; f) the test result obtained or, if the repeatability has been checked, the final result obtained. Copyright International Organization for Standardization Provided by IHS under license with ISO Not for ResaleNo reproduction or networking permitted without license from IHS--`,,```,,,,````-`-`,,`,,`,`,,`---ISO 663:2007(E) © ISO 2007 – All rights reserved 5Annex A (informative) Results of interlaboratory tests Interlaboratory tests on the determination of insoluble impurities in palm oil, crude palm oil and palm kernel oil were organized by the Federation of Oils, Seeds and Fats Associations (FOSFA) and carried out in accordance with ISO 5725-2. The results are shown in Table A.1. Table A.1 — Results of interlaboratory tests on different oil Sample RDB palm oleinRDB palm oil Crude palm kernel oil Crude palm olein Crude fish oil Crude palm oil Number of participating laboratories 16 35 41 27 41 12 Number of laboratories retained after eliminating outliers 16 31 33 26 35 11 Number of individual test results of all laboratories on each sample 16 93 66 52 70 22 Mean value, % 0,004 0,008 0,012 0,016 0,021 0,025 Repeatability standard deviation, sr0,003 0,003 0,003 0,005 0,004 0,004 Repeatability coefficient of variation, % 57,1 41,1 22,4 30,5 20,4 14,8 Repeatability limit, r (sr× 2,8) 0,007 0,009 0,008 0,013 0,012 0,010 Reproducibility standard deviation, sR0,005 0,010 0,010 0,009 0,009 0,013 Reproducibility coefficient of variatio