Acetic acid for industrial use — Methods of test — Part 9: Visual limit test for inorganic sulphates
Specifies a method for a visual comparison of the turbitity obtained by adding a barium chloride solution to a solution of a test portion acidified with hydrochloric acid, with that similarly obtained from a sulphate solution of known concentration. Using a test portion of 100 g, the method is applicable directly to products having inorganic sulphate contents in the range 0,001 % (m/m) to 0,1 % (…
Acetic acid for industrial use — Methods of test — Part 10: Visual limit test for heavy metals (incl...
The principle consists in conversion of heavy metals, such as lead, copper and iron, to their sulphides by treatment with sodium sulphide in ammoniacal solution, and visual comparison of the colour produced with that of a standard lead solution similarly treated. The method detects only the heavy metals present in non-complex form. Using a test portion of 25 g, the method is applicable directly…
Acetic acid for industrial use — Methods of test — Part 1: General
Gives general instructions and also specifies the methods to be used for the determination of dry residue after evaporation on a water bath, for the determination of the crystallizing point (temperature) of glacial acetic acid, for the determination of water content, for the measurement of colour and for the determination of arsenic content. The method is applicable to products having acedic acid…
Acetic acid for industrial use — Method of test — Part 2: Determination of acetic acid content — Tit...
The principle consists in titration of a test portion with standard volumetric sodium hydroxide solution, using phenolphthalein as indicator. Calculation of the acid content, making allowance for any formic acid present, determined separately (see ISO 753/3). This International Standard has also been approved by the International Union of Pure and Applied Chemistry (IUPAC). International…
Incineration of a test portion at a temperature of 900 °C, until complete disappearance of the carbon in the residue. The method specifies a procedure for the evaluation of natural and added mineral substances together. It applies to contents up to 2 %. It does not apply to hydrolysis products nor to oxidized starches, nor to other products containing more than 0,2 % of chloride. In other cases,…
Fruits, vegetables and derived products — Determination of zinc content — Part 2: Atomic absorption ...
The method consists is decomposing of organic matter by a dry or wet method and determing of the Zn + cation by a suitable spectrometer. For some liquid samples the determination may be carried out directly, without previous decomposition.
Phosphoric acid for industrial use — Determination of lead content — Atomic absorption spectrometric...
The lead is extracted from a diluted test portion into a solution of diethylammonium diethyldithiocarbamate in xylene. The xylene extract is separated and aspirated into the acetylene/air flame of an atomic absorption spectrometer. The spectrometric measurements are carried out at a wavelength of about 217 nm or, alternatively, about 283 nm. The method is applicable to phosphoric acids having…
Cryolite, natural and artificial, and aluminium fluoride for industrial use — Determination of phosp...
Specifies a method based on the fusion of a test portion with sodium carbonate and boric acid and dissolution in perchloric acid solution, followed by formation of the ammonium molybdophosphate complex and extraction of the complex with isobutyl acetate. The solution is absorbed into an acetylene/dinitrogen monoxide flame and the molybdenum, and hence the phosphorus, is determined by measuring…
