71.060.40 - Bases

A test portion is introduced into a solution of boric acid and the solution obtained is titrated with a standard volumetric solution of sulfuric acid in the presence of methyl red as indicator. The method is applicable to solutions containing not more than 35 % (m/m) of ammonia.

A test portion is evaporated in a tared platinum dish and the residue is weighed after drying at 105 2 °C. The method is applicable to solutions containing not more than 35 % (m/m) ammonia.

Covers a method applicable to liquid or solid products having mercury contents greater than 0,02 mg/kg. The principle of determination is based on oxidation of the mercury contained in a test portion to mercury(II) ions by potassium permanganate in the presence of sulphuric acid, reduction of the excess oxidant by hydroxylammonium chloride, reduction of the mercury(II) ions to mercury by tin(II) chloride, entrainment of the mercury in air or nitrogen, passage of the gaseous mixture through a mea...view more

Applicable to products having contents, expressed as CO2 , of more than 0.01 % (m/m). Relates to a procduct containing neither sulphides nor chlorates or only sulphides or only chlorates. Preliminary test by boiling an acidified test sample in the presence of methyl orange and with a lead acetate paper strip in the vapour. The sulphides blacken the paper and chlorates delolourize the methyl orange. Products containing neither sulphides nor chlorates: liberation of carbon dioxide by acidification...view more

Indicates the conditions under which the test sample shall be prepared and relates to particular properties which require particular precausions: the samples shall be taken rapidly in a dry atmosphere, storage in an airtight bottle. The bottle shall be made from an inert material such as polyethylene. Preparation of the main solution with distilled carbonat- free water. If the silica content is to be determined the test portion shall be dissolved in a container made from silica-free material suc...view more

Method for determination of the titre; this is expressed conventionally as percentages by mass of NaOH, a) as total alkalinity and b) as caustic alkalinity, corresponding to the total alkalinity less the alkalinity due to carbonates. The principle consists in titration of the total alkalinity with standard volumetric hydrochloric acid solution in the presence of methyl orange as indicator. Calculation of the two amounts a) and b). The mass of carbon dioxide is determined by the method specified ...view more

Provides certain indications relating to the sampling and indicates the conditions under which the test sample should be prepared The special properties which make particular precautions essential such as hygroscopic characteristics, absorption of carbon dioxide, corrosive action on containers, should be stressed. The preparation of the main solution is carried out by dissolution of the test portion in distillated water or by transfer of the liquid test portion directly and quantitatively in a o...view more

The method is applicable to products of which the chloride content is greater than 0.005 % (m/m). The procedure based on titration of the chloride ions with mercury(II) nitrate in the presence of diphenylcarbazone as indicator. - Replaces ISO Recommendation R 981-1969.