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The method is applicable to products having carbonyl compounds contents equal to or greater than 0.01 % (m/m). The method only allows determination of those carbonyl compounds which react under the specified conditions. The principle is based on the reaction of hydroxylammonium chloride with the carbonyl compounds in a test portion and titration of the hydrochloric acid formed with standard…

The method is applicable to products having aldehyde contents in the range 0.00025 % (m/m) to 0.00125 % (m/m). The principle is based on the reaction of the aldehydes present in a test portion with Schiff reagent. Visual comparison of the colour obtained with the colours of standard colorimetric solutions containing known quantities of acetaldehyde. - International Standards ISO 1388/1 to ISO…

The principle is based on the conversion of methanol present in a test portion to formaldehyde by oxidation. The oxidation is carried out with a solution of potassium permanganate in phosphoric acid. Reaction of the formaldehyde formed with chromotropic acid (4,5-dihydroxynaphthalene-2,7-disulphonic acid). Photometric measurement of the violet coloration obtained at a wavelength of about 570 nm…

The principle is based on the conversion of the methanol present in a test portion to formaldehyde by oxidation with a solution of potassium permanganate in phosphoric acid. Reaction of the formaldehyde formed with Schiff reagent. Visual comparison of the colour obtained with the colours of standard colorimetric solutions containing known quantities of formaldehyde. - International Standards ISO…

The principle is based on distillation of a test portion in the presence of water, addition to the distillate of a saturated sodium chloride solution and measurement of the volume of insoluble hydrocarbons. A Hempel fractionating column with Liebig condenser is used for the distillation. - International Standards ISO 1388/1 to ISO 1377/12 cancel and replace ISO Recommendation R 1388-1970 of which…

The document also specifies the methods to be used for the determination of density at 20 °C, for the determination of dry residue after evaporation on a water bath, for the determination of water content, and for the measurement of colour. - International Standards ISO 1388/1 to 1388/12 cancel and replace ISO Recommendation R 1388-1970 of which they constitute a technical revision.

The principle of the determination consists in reaction of the acetaldehyde present in a test portion with an excess of sodium hydrogen sulphite solution, and iodometric titration of the residual sodium hydrogen sulphite. The method is applicable to products having acetaldehyde monomer contents equal to or greater than 0,01 % (m/m). This International Standard as also been approved by the…

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…

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…

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…