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ISO 6884 pdf free download

ISO 6884-2008 pdf free download.Animal and vegetable fats and oils – Determination of ash.
This International Standard specifies a method for the determination of ash, applicable to all animal and vegetable fats and oils, including acid oils.
2 Normative references
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 (induding 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 ash
(animal and vegetable fats and oils) inorganic residue left after incineration under the conditions specified in this International Standard
NOTE The ash yield is expressed as a percentage mass fraction of the dry product.
4 Principle
The sample is combusted under mild heating and the residue is incinerated at 550 °C to 600 °C until free Iron, carbon particles. The residue obtained is then weighed.
5 Reagents
WARNING — Comply with any local regulations which specify the handling of hazardous substances. Follow technical, organIzational, and personal safety measures.
During the analysis, unless otherwise stated, use only reagents of recognized analytical grade and distilled or demineralized water or water of equivalent punty.
5.1 Hydrogen peroxide solution, = 10 % volume fraction.
5.2 Ammonium carbonate.
6 Apparatus and materials
Usual laboratory apparatus and, in particular the following.
6.1 Crucible (low form) of capacity 50 ml, preferably of silica o platinum.
6.2 Hotplate or flame burner.
6.3 Furnace, capable of being maintained between 500 °C and 600 °C.
6.4 Filter paper, ashless.
6.5 Water-bath, boiling.
6.6 Desiccator.
6.7 AnalytIcal balance, capable of being read to the nearest 1 mg.
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 (1),
8 Preparation of the test sample
Prepare the test sample from the laboratory sample in accordance with ISO 661.
9 Procedure
9.1 Crude and refined fats and oils
9.1.1 First heat the crucible (6.1) in the furnace (6.3) maintained at 550 °C to 600 °C, then cool in a desiccator (6.6) and weigh to the nearest 1 mg. Weigh, to the nearest 10 mg, about 10 g of the test sample (Clause 8) into the crucible. Heat carefully on the hotplate or over the flame burner (6.2) in a fume cupboard until the sample ignites.
For low ash yields, a larger test portion may be taken by adding successive portions of 10 g after the initial ashing; for high ash yields, a smaller test portion may be used. With an increased quantity of oil, a wick of ashless fitter paper may be inserted and lit whilst heating the oil on a hotplate.
The initial heating may be carried out in the mouth of the furnace, if the furnace is installed in a fume cupboard.
9.1.2 When the burning ceases, transfer the crucible to the furnace (6.3) maintained at 550 °C to 600 °C. Maintain the crucible at this temperature for 4 h or for a shorter time if a carbon-free residue is obtained more rapidly. A carbon-free residue is shown by the appearance of the ash, which becomes red-brown (due to the presence of iron) or white, with no black particles remaining in the residue.
9.1.3 If the residue is not carbon-free after 4 h, add a few drops of hydrogen peroxide (5.1), dry on a boiling water-bath (6.5), and reheat in the furnace (6.3) to assist in the removal of carbon.
It may be necessary to repeat this treatment.
9.1.4 When the residue is carbon-free, allow to cool in a desiccator (6.6), and weigh to the nearest I mg.ISO 6884 pdf download.

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