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1、INTERNATIONAL STANDARD INTERNATIONAL ORGANIZATION FOR STANOARDlZATlON .MEXaYHAPOllHAI OPTAHH3AUMR II0 CTAHAAPTL13AUAM.ORGANISATION INTERNATIONALE DE NORMALlSATlON Sodium hydroxide for industrial use - Sampling - Test sample - Preparation of the main solution for carrying out certain determinations H
2、ydroxyde de sodium 5 usage industriel - Pr6l - the laboratory sample shall be stored in an airtight bottle, protected from contact with the atmosphere; - the bottle shall be made of a material which does not contaminate the sample with the elements to be determined (for example, a silica-free materi
3、al such as polyethylene, if the determination of silica content is intended). 2.2 For the methods of sampling, and the number of portions to be drawn from a given quantity, see IS0 . . .I) 3 TEST SAMPLE 3.1 The laboratory sample shall be protected from the atmosphere and handled in such a way that n
4、o appreciable absorption of water or carbon dioxide is possible during the operations. Crushing or grinding in a mortar, if necessary, shall be carried out as rapidly as possible in an atmosphere of maximum dryness. It is recommended that these operations should be carried out in a glove box from wh
5、ich moisture and carbon dioxide have been removed by the introduction, at least 1 h before the sample is treated, of flat dishes, one containing phosphorus(V) oxide and another potassium hydroxide pellets. 3.2 Take about 300 g of the laboratory sample and, in the case of a solid product, grind it, i
6、f necessary, to ensure that the greatest dimension of the particles does not exceed about 6 mm. Place the sample in an airtight container made of a material which will not contaminate the sample with the elements to be determined, and which is of such a capacity that it is almost completely filled.
7、The container shall bear a label, with a protective coating, indicating : - the origin and identification of the test sample; - the date on which it was placed in the container. 4 PREPARATION OF THE MAIN SOLUTION FOR CARRYING OUT CERTAIN DETERMINATIONS (SOLUTION A) 4.1 Test portion In a glass weighi
8、ng bottle fitted with a ground lid, weigh, to the nearest 0.01 g, a mass of the solid or liquid test sample corresponding to a little less than 40 g of NaOH. 4.2 Reagent Distilled carbonate-free water, or water of equivalent purity, shall be used. 4.3 Procedure (Preparation of the main solution (A)
9、4.3.1 Solid products Dissolve the test portion (4.1) in about 200 ml of water: Cool to room temperature and transfer the solution quantitatively to a 1 000 ml one-mark volumetric flask, dilute almost to the mark, cool again to room temperature, complete the dilution to the mark, and mix. 4.3.2 Liqui
10、d products Transfer the test portion (4.1) directly and quantitatively to a 1 000 ml one-mark volumetric flask, dilute almost to the mark, cool again to room temperature, complete the dilution to the mark and mix. NOTE - If the silica content is to be determined, dissolve the test portion in a conta
11、iner made of silica-free material (for example, polyethylene or silver). In the case of a polyethylene container, cool the outer walls with running water in order to prevent softening. After the dilution to the mark in a 1 000 ml one-mark volumetric flask, transfer the solution to a dry polyethylene
12、 bottle with an airtight closure. 1) In preparation. 1 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/25/2007 09:44:16 MDTNo reproduction or networking permitted without license from IHS -,-,-