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…
Butan-1-ol for industrial use — Methods of test — Part 1: General
Gives general instructions ans also specifies the methods to be used for the determination of density at 20 C, the determination of aldehydes and ketones content, the determination of destillation yield, the determination of dry residue after evaporation on the water bath, the determination of bromine number, the measurement of colour and the determination of water content. International…
Fruits, vegetables and derived products — Determination of total sulphur dioxide content
The method consists in acidifying and heating a test portion, entraining, in a current of nitrogen, the gas liberated, absorbing and oxidizing the gas by bubbling it through a neutral, dilute hydrogen peroxide solution, then determining the sulphuric acid thus formed using standard volumetric sodium hydroxide solution. Verification of the determination is described in the annexes A and B,…
Liquid fruit and vegetable products — Determination of sulphur dioxide content (Routine method)
The determination of free sulphur dioxide consists in direkt iodometric titration of the product at a pH between 0,7 and 1, followed by blank titration of the product, freed from sulphur dioxide by boiling under reflux or by binding its free sulphur dioxide content with an exess of acetaldehyde or propioaldehyde. The bond sulphur dioxide is determined after titration of free compound, rendering…
Solid mineral fuels — Determination of phorphorus content — Reduced molybdophosphate photometric met...
For taking the phosphorus into solution the following two methods are specified: The carbonaceous material is removed by ashing in amuffle furnace under specified conditions and the phosphorus is extracted by treatment with hydrofluoric and sulphuric acids. The carbonaceous material is removed by repeated oxidation with nitric acid in the presence of sulphuric acid. The determination is carried…
