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  • ISO 1592-1977 - 中外标准 - - 1977/11 - 废止
    The procedure is based on the catalytic conversion of nitrogen present in a test portion to ammonia by heating in concentrated sulphuric acid solution. Distillation and absorption of the ammonia in an excess of standard volumetric sulphuric acid solution and back-titration with standard volumetric sodium hydroxide solution in the presence of an indicator. - Replaces ISO Recommendation R 1592-1970.
  • ISO 1593-1977 - 中外标准 - - 1977/11 - 废止
    The principle consists in titration of the alkalinity of a test portion with a standard volumetric hydrochloric acid solution in the presence of an indicator. - Replaces ISO Recommendation R 1593-1970.
  • ISO 1594-1977 - 中外标准 - - 1977/11 - 废止
    The procedure consists in the ignition of a test portion in a platinum dish at (800 25) °C to constant mass. - Replaces ISO Recommendation R 1594-1970.
  • ISO 4274-1977 - 中外标准 - - 1977/10 - 废止
    Applicable to products having contents of equal to or more than 0.05 % (m/m) (with flame atomic absorption) or 0.1 % (m/m) (with fotometric absorption). Covers the formation of a complex between biuret and copper(II) sulphate in alkaline medium. Fixation of this complex on an anion exchange resin. Elution of Cu first with a potassium nitrate solution and then with a nitric acid solution. Flame atomic absorption: aspiration of the solution into an acetylene-air flame and measurement of the absorption of the 325-nm line emitted by a copper hollow-cathode lamp; or by photometric absorption: formation of a coloured complex between Cu and zinc dibenzyldithiocarbamate, extraction with carbon tetrachloride and measurement at a wavelength of about 435 nm. Has also been approved by the IUPAC.
  • CNS 4138-1977 - 中外标准 - - 1977/6 - 现行
    三氯乙烯工业的
  • CNS 4128-1977 - 中外标准 - - 1977/6 - 现行
    杂酚油煤焦油溶剂化学性质
  • ISO 1390-3-1977 - 中外标准 - - 1977/6 - 废止
    The procedure is based on the potentiometric titration of the free acidity in a test portion with a standard volumetric triethylamine solution in anhydrous methyl ethyl ketone (butanone). - ISO 1390, Parts 1 to 6, replace ISO Recommendation R 1390-1970.
  • ISO 1390-2-1977 - 中外标准 - - 1977/6 - 废止
    The principle is based on the measurement of colour, by the method specified in ISO 2211, of a test portion in the molten state. The results are expressed in Hazen units. - ISO 1390, Parts 1 to 6, replace ISO Recommendation R 1390-1970.
  • ISO 1390-4-1977 - 中外标准 - - 1977/6 - 废止
    The principle consists in the dissolution of a test portion in diluted standard volumetric sodium hydroxide solution and titration with standard volumetric sodium hydroxide solution in presence of phenolphthalein as indicator. - ISO 1390, Parts 1 to 6, replace ISO Recommendation R 1390-1970.
  • ISO 1390-1-1977 - 中外标准 - - 1977/6 - 废止
    The document also specifies the method to be used for the determination of the crystallizing point. Before carrying out the tests, the sample shall be grind to a fine powder and shall be mixed thoroughly. Exposure to moist air may lead to the formation of maleic acid. - ISO 1390, Parts 1 to 6, replace ISO Recommendation R 1390-1970.
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