Abstract / scope
The principle of the method consists in the dilution of a sample with a suitable solvent, separation of the pigment by centrifugation. Three methods, dependent on the binder of the product being examined, are described. Extraction of the separated pigment with hydrochloric acid at a ratio of mass:volume of 1:15, except for the determination of "soluble" lead; in that case, extraction is carried out at a ratio of 1:1000. Evaporation to dryness of the liquid portion obtained by centrifuging, analysis by dry ashing and extraction of the ash with nitric acid. For coating materials in powder form, extraction is carried out without prior separation of the binder.