Fruits, vegetables and derived products — Determination of arsenic content — Silver diethyldithiocar...
The method consists in decomposing a test portion, reducing arsenic (V) to arsenic (III) with tin(II) chloride and transforming the arsenic into arsine by action of nascent hydrogen, forming a red coloured complex by the action of the arsine on silver diethyldithiocarbamate and measuring at a wavelength of 520 nm.
Dried milk — Determination of nitrate and nitrite contents — Method by cadmium reduction and photome...
Describes a method suitable for whole, partly skimmed and skimmed milk powder. The principle of determination consists in dissolving the dried milk in water, precipitating the fat and proteins, filtering and reducing the nitrate to nitrite in a portion of the filtrate by means of copperized cadmium. The sampling shall be made as specified in ISO 707. The apparatus for nitrate reduction is shown…
Starches and derived products — Determination of chloride content — Potentiometric method
A solution or suspension of the sample is titrated with a standard volumetric silver nitrate solution. The method is not applied to cationic starches and amyloids soluble when cold.
Citrus fruits and derived products — Determination of essential oils content (Reference method)
The method consists in boiling a test portion, diluted or undiluted, and steam entrainment of the oils which are collected in a graduated tube; after cooling, direct reading from this tube of the volume of the oils separated from the destillate.
Gives general instructions and specifies methods od analysis. The methods to be used are determination of density at 20 °C, determination ofdry residue after evaporation on a water bath, measurement of colour, determination of distillation yield, determination of water content, detection of the alkalinity or acidity to phenolphthalein, spectrometric detection of content of carbonyl compounds in…
Spices and condiments — Determination of extraneous matter content
Specifies a method based on the physical separation and weighing of the extraneous matter in a test portion. Lists the apparatus to be used and describes sampling, procedure, expression of results and the details to be included in the test report.
Surface active agents — Water dispersing power in dry cleaning solvents
From premixes containing different amounts of water and relatively constant amounts of the detergent and solvent dry cleaning solutions with the desired final concentration of detergent are prepared. The water solubilizing power of the detergent is determined by visula assesment of the optical density of the solutions, and, after adding water to those solutions that are still clear, the…
Starches and derived products — Determination of total phosphorus content — Spectrophotometric metho...
Destruction of the organic substances by digestion with a sulpho-nitric mixture and conversion of phosphates to orthophosphates. Formation of a phosphomolybdate. Measurement of the intensity of the blue colour at a wavelength of 825 nm. The method applies to contents up to 5 % (m/m).
Steel and cast iron — Determination of manganese content — Spectrophotometric method
The method is applicable to products having manganese contents between 0,001 and 4 % (m/m). Gives principle, reagents, apparatus, sampling, procedure, expression of results and test report.
