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  • ISO 2228-1972 - 中外标准 - - 1972/12 - 废止
    The results obtained by this method will include the methanol freed from combined forms. These are however not usually present at higher levels to effect the results. The principle consists in esterfication of the methanol present with formic acid using sulphuric acid as a catalyst. Distillation of the methyl formate into sodium hydroxide solution and back-titration of the excess sodium hydroxide with a standard volumetric sulphuric acid solution, using phenolphthalein as indicator. This method is intended for methanol contents greater than 0,2 %.
  • ISO 2226-1972 - 中外标准 - - 1972/12 - 废止
    The specified method is applicable to the detection of Fe contents less than 0,0004 % (m/m). The principle consists in conversion of any iron present into the sulphate by evaporation to dryness in the presence of sulphuric acid, and reduction of iron (III) by means of hydroxylammonium chloride. Formation of a iron (II) 2,2''-bipyridyl complex. Photometric measurement of the coloured complex at a wavelength of about 522nm. As an alternative to measurement of absorbance the test solution prepared may be compared visually the Nessler cylinders with standard matching solution or with standard colorimetric discs.
  • ISO 2222-1972 - 中外标准 - - 1972/12 - 废止
    The specified method is applicable when the required limit is not greater than 0,1 % and not less than 0,001 %. If the required limit lies outside that range, the mass of the test portion should be changed. The principle ot the test consists in comparison of the turbidity obtained by the addition of barium chloride solution to a solution of the sample, in the presence of hydrochloric acid, with that similarly produced from a sulphate solution of known concentration.
  • ISO 2224-1972 - 中外标准 - - 1972/12 - 废止
  • ISO 2227-1972 - 中外标准 - - 1972/12 - 现行
    The specified method is applicable to HCHO contents between 25 5 and 45 %. The field of application may be extended by siutably modifying the mass of the test portion. The principle consists in the reaction of the test solution with a neutral sodium sulphite solution, and acidimetric titration of the liberated sodium hydroxide in presence of thymolphthalein as indicator.
    溶液容量分析甲醛含量测定化学分析化学分析和试验Chemical analysis and testingDetermination of contentFormaldehydeSolutionsVolumetric analysis
  • ISO 2221-1972 - 中外标准 - - 1972/12 - 废止
    The method, as specified, is applicable when the required limit is not greater than 0,05 % and not less than 0,0005 %. If the required limit lies outside that range, the mass of the test portion should be changed. The principle of the test consists in comparison of the turbidity obtained by the addition of silver nitrate solution to a solution of the sample, in the presence of nitric acid, with that similary produced from a chloride solution of known concentration.
  • ISO 2223-1972 - 中外标准 - - 1972/11 - 废止
    The method detects only the heavy metals present in non-complex form, the sulphides of which are precipitated in acid solution. The method is not specific for any one heavy metal. The principle consists in conversion of heavy metal, such as lead and copper, in acid solution to their sulphides, and comparison of the colour produced with that given by an aliquot volume of standard lead solution treated with hydrogen sulphide in the same way.
  • ISO 2225-1972 - 中外标准 - - 1972/11 - 废止
  • CNS 3341-1972 - 中外标准 - - 1972/10 - 现行
    苯酚工业的
  • CNS 3387-1972 - 中外标准 - - 1972/10 - 现行
    气体分析色谱法脂族烃气体
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