Chromium ores and concentrates — Determination of silicon content — Molecular absorption spectrometr...
The molecular absorption spectrometric method (A) is applicable to products having silicon contents from 0,05 to 0,5 % (m/m), the gravimetric method (B) is applicable to products having silicon contents from 0,5 to 15 % (m/m). ISO 5997 should be read in conjunction with ISO 4297. Specifies among other things principle, reagents, apparatus, procedure, spectrometric measurement (method A only) and…
Crude sodium borates for industrial use — Determination of total and alkali-soluble calcium and magn...
A test solution is prepared by one of the two following ways: a) fusion of a test portion with sodium carbonate in the case of total calcium and magnesium contents, and b) from an aliquot portion of "solution A" (ISO 2217) for alkali-soluble calcium and magnesium contents. Lanthanum ions are added to the solution to suppress certain interferences. The solution is aspirated into an…
Crude sodium borates for industrial use — Determination of total and alkali-soluble calcium and magn...
The calcium content is determined by titration of an aliquot portion of the test solution with ethyleneglycol-bis-(2-aminoethyl)-N,N,N',N'-tetra acetic acid, disodium salt (EGTA) solution using 2-carboxy-2'-carboxy-2'-hydroxy-5'-sulphoformazylbenzene (Zincon) as indicator. The combined magnesium and calcium contents are determined by titration of a further aliquot portion…
Spices, condiments and herbs — Determination of volatile oil content
Describes a method the principle of which consists in distilling an aqueous suspension of the product and collecting the distillate in a graduated tube containing a measured volume of xylene to fix the volatile oil. After separation of the organic from the aqueous phases the total volume of the organic phase is read and the volatile oil content is calculated after deduction of the volume of…
The specified methods apply to sampling from containers of all sizes. Separate methods are described for sampling at the point of manufacture, sampling at susequent stages in the distribution chain and sampling of retail packs. In addition, different procedures or special precautions are specified depending on wether the samples are to be used for examination of particle characteristics (for…
Paints and varnishes — Determination of total mercury — Flameless atomic absorption spectrometric me...
The reference method described is applicable to products having total mercury contents in the range of about 0.01 % (m/m) to 0.5 % (m/m). May also be extended to products with a total content of more than 0.5 % (m/m). The principle of the method consists in the combustion of the test portion with oxygen in an enclosed system. Reduction of the mercury(II) compounds contained in the resulting…
