Solvent acetates for industrial use — Methods of test
Gives general instructions and specifies methods of analysis for these chemical products. The methods are the following: determination of density at 20 °C; determination of dry residue after evaporation on a water bath; measurement of colour; determination of distillation characteristics; determination of water content; determination of acidity; and determination of ester content (titrimetric…
Phenol, o-cresol, m-cresol, p-cresol, cresylic acid and xylenols for industrial use — Methods of tes...
The test may be carried out on products as received or on a dried sample. The method specified in ISO 2208 shall be applied for drying. The principle of the method consists in cooling the liquid or liquefied test portion and observation of the temperature during crystallization under defined conditions. A simplified crystallization point apparatus is given in the figure. It takes into account the…
Phenol, o-cresol, m-cresol, p-cresol, cresylic acid and xylenols for industrial use — Methods of tes...
The method is applicable to products having high cresol contents. The principle consists in distillation of a test portion inder carefully defined conditions. Either determination of the temperatures corresponding to the condensate volumes defined or determination of the volume condensate when the thermometer indicates each of the distillaton temperatures (i.e. plotting temperature as a function…
Phenol, o-cresol, m-cresol, p-cresol, cresylic acid and xylenols for industrial use — Methods of tes...
Applicable to products having a high o-cresol content and a high m-cresol content. The principle consists in distillation of a tast portion under carefully defined conditions and determination of the mass of residue obtained. The distillation is carried out according to ISO 918. When all the water has distilled over, continue the distillation without intermediate measurements, until either the…
Acetic acid for industrial use — Methods of test — Part 3: Determination of formic acid content — Io...
Specifies the determination of total reducing matter and of reducing compounds other than formic acid. The principle consists in oxidation of formic acid and other reducing compounds in a test portion with an excess of sodium hypobromit solution. Determination of the excess sodium hypobromite by iodometry. Oxidation of reducing compounds other than formic acid with an excess of potassium bromide-…
Phosphoric acid for industrial use (including foodstuffs) — Determination of hydrogen sulfide conten...
The hydrogen sulphide in a test portion is removed in a stream of nitrogen and absorbed in a solution of sodiumhydroxide in aqueous acetone. the sulphide ions are titrated with standard volumetric mercury(II) acetate solution, in the presence of 1,5-diphenylthiocarbazone (dithizone) as indicator. The method is applicable to products having hydrogen sulfide contents greater than or equal to 0.05…
Phosphoric acid for industrial use — Determination of higher soluble sulfate contents — Titrimetric ...
The sulphate present in a test portion is reduced to sulphide by a mixture of hydriodic and phosphinic (hypophosphorous) acids. The hydrogen sulphide evolved is absorbed in an excess of cadmium acetate solution. The cadmium sulphide formed is oxidized by an excess of standard volumetric potassium iodate/iodide solsution, and the excess iodine is titrated with standard volumetric sodium…
