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  • ISO 2753-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the manner in which this method is to be applied in a reaction of any water present in urea with a solution of iodine and sulphur dioxide in a mixture of pyridine and methanol (Karl Fischer reagent). This reagent is first standadized by titration with a precisely known mass of water. The end point of the reaction is read by the direct visual or direct electrometric method. The method has also been approved by the IUPAC.
  • ISO 2756-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the sampling, the determination of the distillation characteristics subjected to the modifications appropriate for this product, of the water content, of the density at 20 0C and of the crystallizing point. Has also been approved by the IUPAC.
  • ISO 2496-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the sampling, the determination of distillation characteristics, of residue on evaporation, of the acidity to phenolphthalein and the measurement of colour in Hazen units. The butan-2-ol sample is stored in a dark coloured, glass-stoppered bottle of such a size that it is nearly filled by the sample.
  • ISO 2887-1973 - 中外标准 - - 1973/12 - 废止
    Lays down the treatment of a test portion by dilution with water (or with ethanol or propan-2-ol if the sample is not completely soluble in water) and removal of carbon dioxide by passing a strem of nitrogen through the solution. The determination is carried out by titration with a standard volumetric sodium hydroxide solution using phenolphthalein as indicator. The nitrogen used shall be free from ammonia and carbon dioxide.
  • ISO 2757-1973 - 中外标准 - - 1973/12 - 废止
  • ISO 2886-1973 - 中外标准 - - 1973/12 - 废止
    The principle consists in the evaporation to dryness of a test portion and dissolution of the residue in hydrochloric acid. Reduction of iron(III) by means of hydroxylammonium chloride. Formation of the iron(II)- 2,2''-dipyridyl complex. Photometric measurement of the coloured complex at a wavelength of about 522 nm. Specifies the use of a spectrophotometer or photoelectric absorptionmeter. As an alternative it is permitted to employ a visual method comparing the test solution with a series of reference solutions. Has also been approved by the IUPAC.
  • ISO 2752-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the principle of measurement, at (20 0.5) 0C, of the quantity of 0.01 N sodium hydroxide standard volumetric solution required to take the pH of a solution containing 50 g of sample in 100 ml of water to a pH of 8.3 after addition of formaldehyde. Has also been approved by the IUPAC.
  • ISO 2888-1973 - 中外标准 - - 1973/12 - 废止
    Pretreatment of the water used, freshly boiled and cooled, by neutralization by addition of the standard volumetric sodium hydroxide solution or sulphuric acid solution as required. Addition of the test portion and titration with the standard volumetric sodium hydroxide solution in presence of phenolphthalein as indicator until the apperance of a pale pink colour.
  • ISO 2755-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the sampling, the determination of distillation characteristics, of the density at 20 0C, of residue on evaporation, of the water content, of the acidity and the measurement of colour in Hazen units. Has also been approved by the IUPAC.
  • ISO 2497-1973 - 中外标准 - - 1973/12 - 废止
    Specifies the sampling, the determination of distillation characteristics, of the density at 20 0C, of residue on evaporation on a water bath, of the water content, of alcoholic impurities, of the acidity to phenolphthalein, the examination of residual odour and the measurement of colour in Hazen units.
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