Caseins and caseinates — Determination of protein content (Reference method)
Does not apply to caseins and caseinates containing ammonium caseinate or other ammonium compounds, or other nitrogenous nonprotein compounds. The principle of determination consists in digesting a test portion with a mixture of potassium sulphate and sulphuric acid, in the presence of copper(II) sulphate as catalyst, to convert organic nitrogen into ammoniacal nitrogen, distilling and absorbing…
Meat products — Determination of starch content (Reference method)
The method consists in heating a test portion with ethanolic potassium hydroxide solution until the meat components are totally dissolved, decanting, washing of the remaining residue with hot ethanol, filtering, dissolving in hydrochloric acid, and hydrolysis, followed by titrimetric determination of the glucose formed.
Hardmetals — Determination of contents of metallic elements by X-ray fluorescence — Fusion method
Specifies methods for the determination of the presence, type, and distribution of porosity and uncombined carbon in hardmetals, furthermore apparatus, preparation of test pieces, procedure and test report. Figures show the types of apparent porosity and uncombined carbon.
Fruits, vegetables and derived products — Determination of iron content — 1,10- Phenanthroline photo...
The method consists in decomposing the organic matter, followed by reduction of trivalent iron by hydroxyammonium chloride, forming, in a buffered medium, of the stable iron(II)/1,10 phenanthroline complex, and photometric measuring of the red-coloured complex at a wavelength of 508 nm.
Fruits, vegetables and derived products — Determination of benzoic acid content — Spectrophotometric...
The method consists in homogenizing the product, followed by dilution and acidification of a test portion, extraction of the acid by diethyl ether, then alkaline re-extraction of this acid and purifying by oxidation using acidified potassium dichromate, determination of the acid with a suitable spectrophotometer. The method cannot be applied in the presence of p-chlorobenzoic acid and cinnamic…
Steel — Determination of low carbon contents — Part 4: Coulometric method after combustion
The coulometric method for the determination of low carbon contents in steels after combustion in a current of oxygen is applicable to carbon contents between 0,005 and 0,1 %. Specifies principle, reagents, apparatus, sampling, procedure, special case: carbon contents less than 0,010 % and test report.
