All grades of fluorspar — Determination of carbonate content — Titrimetric method
The principle of the method specified is treatment of a test portion with hydrochloric acid solution, absorption of the evolved carbon dioxide in barium hydroxide solution, neutralization of excess alkali with hydrochloric acid solution, addition of an exactly measured excess of a standard volumetric hydrochloric acid solution to dissolve the precipitated barium carbonate and back-titration with…
Acid-grade and ceramic-grade fluorspar — Determination of sulfide content — Iodometric method
The principle of the method specified is digestion of a test portion in a sealed apparatus in a mixture of hydrochloric acid, tin(II) chloride and boric acid solutions, absorption of the liberated hydrogen sulfide, entrained in a stream of oxygen-free argon or nitrogen, in zinc acetate solution and iodometric determination of the zinc sulfide formed. The method is applicable to products having a…
Photography — Photographic-grade chemicals — Test methods — Part 5: Determination of heavy metals an...
The method is based on preparation of test samples and heavy metals standard solutions, preconditioning them, addition of sodium sulfide solution (for determination of heavy metals) or 1,10-phenanthroline reagent (for determination of iron), dilution with water, mixing well, transfer to two Nessler colour-comparison cylinders, and comparing the colour of both solutions.
Photography — Photographic-grade chemicals — Test methods — Part 6: Determination of halide content
The method is based on weighing the test portion, dissolution in water, transfer of a 20 ml aliquot in a beaker, pipetting halide standard A or B into a second beaker, adding nitric acid solution plus silver nitrate solution to each beaker, dilution with water, transfer of the treated solutions into separate Nessler colour-comparison cylinders, and observing the turbidity of the two solutions.
Photography — Photographic-grade chemicals — Test methods — Part 10: Determination of sulfide conten...
The method is based on weighing a test portion, dissolution in water, transfer to one of the Nessler colour-comparison cylinders, pipetting the volume of sulfide standard into the second Nessler colour-comparison cylinder, addition of alkaline lead solution, making up with water, mixing thoroughly, and comparing the colour and clarity of the two solutions.
Acid-grade and ceramic-grade fluorspar — Determination of manganese content — Periodate spectrometri...
Applicable to products having Mn-contents in the range 0,006 % to 0,4 %. Decomposition of the test portion with nitric and perchloric acids. After dilution follows oxidation of manganese to permanganate with sodium metaperiodate. Spectrometric measurement at 545 nm.
Animal and vegetable fats and oils — Determination of residual technical hexane content
The method is based on desorption of volatile hydrocarbons by heating at 80 °C in a closed vessel after addition of an internal standard and determination of the particular volatile hydrocarbons content of the headspace by gas chromatography using packed or capillary columns.
Iron ores — Determination of calcium content — Flame atomic absorption spectrometric method
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for calcium with those obtained from…
Iron ores — Determination of magnesium content — Flame atomic absorption spectrometric method
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for magnesium with those obtained from…
Iron ores — Determination of aluminium content — Part 1: Flame atomic absorption spectrometric metho...
The method is based on decomposition of the test portion by hydrochloric acid/nitric acid, evaporation, ignition of the residue and removal of silica, fusion with sodium carbonate and dissolution of the cooled melt in the filtrate, aspiration of the solution into the flame of an atomic absorption spectrometer, and comparison of the absorbance values obtained for aluminium with those obtained from…
