The principle of the method specified is to decompose a test portion by a mixture of nitric, hydrofluoric and perchloric acids, dissolving the salts in hydrochloric acid after evaporation to fumes of sulfuric acid, extracting the antimony from a dilute hydrochloric acid solution of the decomposed test portion into a solution of tri-n-octylphosphine oxide in 4-methyl-2-pentanone, aspirating the extract into the air/acetylene flame of an atomic absorption spectrometer, and measuring the absorbance at 217,6 nm. Applies to products having an antimony content equal to or greater than 0,001 % (m/m).