Fertilizers — Determination of ammoniacal nitrogen content in the presence of other substances which...
The method consists in entraining, by means of a strong current of air, of the ammonia from a moderately alkaline test mixture at ambient temperature into standard volumetric sulfuric acid solution, and back-titrating of the excess sulfuric acid solution with standard volumetric sodium hydroxide solution.
Phthalic and adipic esters for industrial use — Determination of free alcohols content — Spectrometr...
The free alcohol is reacted with vanadium(V) sodium salt of quinolin-8-ol(8-hydroxyquinoline) to form a coloured complex. The complex is extracted with toluene and then treated with dichloroacetic acid. The spectrometric measurement is carried out at a wavelength of about 620 nm. The method is applicable to products having free alcohol contents between 0,01 and 5,0 % (m/m).
Tool steels and bearing steels — Micrographic method for assessing the distribution of carbides usin...
Specifies a method for assessing steels with C levels between 0,1 % and 1,5 % and a total content of alloy elements less than or equal to 5 %. The use of this method for other steels shall be subject to special agreement. Contains principles, sampling, preparation of samples, assessment of the distribution of carbides, expression of results and test report. An annex gives reference…
Brown coals and lignites — Principles of sampling — Part 2: Sample preparation for determination of ...
The process of sample preparation consists of several operations three of which are fundamental: particle size reduction by crushing or grinding and milling; mixing; decrease of sample mass by dividing the sample (sample division). In most cases, the drying process of the sample is also necessary.
The method consists in preparing of a test solution as specified in ISO 5317, precipitating of potassium ions by sodium tetraphenylborate in a weakly alkaline medium in the presence of disodium ethylenediaminetetraacetate dihydrate (EDTA, disodium salt) and formaldehyde, followed by filtrating of the precipitate, drying and weighing.
Milk — Determination of fat content — Gerber butyrometers
Specifies the characteristics of seven types of butyrometer, their various scale ranges, construction, scales and their graduations, reference temperature and the inscriptions to be marked on the bulb of the butyrometer. Annex A gives information on recommended stoppers and Annex B deals with recommended methods for the determintion of scale errors of butyrometers.
Ferrotitanium — Determination of titanium content — Titrimetric method
The method is applicable to ferrotitanium having titanium contents between 20 and 80 % (m/m). Specifies principle, reagents, apparatus, sample, procedure, expression of results and test report. Figures show the Bunsen valve and the apparatus for titration.
Fruit and vegetable products — Determination of zinc content — Part 3: Dithizone spectrometric metho...
The method consists in decomposing of organic matter, neutralizing of the solution obtained, adding of 1,5-diphenylthiocabazone solution, extracting of the zinc complex thus furmed with chloroform and measuring of the absorbance of the extract at a wavelength of 538 nm.
Green coffee — Determination of loss in mass at 105 degrees C
The method can be considered , by convention, as a method for determining the water content and can be used as such by agreement between interested parties. It consists in heating a test portion at 105 C for 16 h at atmospheric pressure.
