Fruits, vegetables and derived products — Determination of volatile acidity
The method consists in acidifying a test portion with tartaric acid, entraining the volatile acids by steam distillation and titrating the distillate with standard volumetric sodium hydroxide solution in the presence of phenolphthalein as an indicator. The method is applicable to all fresh products, to products preserved without chemical preservatives, and to products to which sulphur dioxide has…
1.1 Scope This standard covers draft hoods for use with: (a) Gas converted central heating equipment; (b) Gas water heaters; (c) Gas converted water heating equipment.
Butane-1,4-diol for industrial use — Determination of degree of unsaturation
A test portion is treated with a solution of bromine in absolute methanol saturated with sodium bromide (Kaufman solution). After addition of potassium iodide solution the liberated iodine is titrated with standard volumetric sodium thiosulfate solution. The degree of unsaturation is expressed as iodine value, the number of grams of iodine absorbed by 100 g of a substance under specified…
Oils of citrus — Determination of CD value by ultraviolet spectrophotometric analysis
The absorbance curve of an ethanolic solution of the oil in the wavelength range from 220 to 440 nm is plotted and from this the CD value is determined. The CD value is the measure of segment CD, expressed in absorbance units for the exact mass of test portion specified in the International Standard appropriate to the essential oil concerned. The determination of segment CD is described in detail.
Acetic acid for industrial use — Methods of test — Part 4: Determination of acetaldehyde monomer con...
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…
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…
