Abstract
It was possible to determine lead in the presence of bismuth in lipsticks by dithizonate colorimetry after complete removal of bismuth by treatment with ion-exchange resin. Separated of bismuth and lead was examined by their determination by atomic absorption spectrophotometry. The test method used was as follows : a sample (1g) of a lipstick containing bismuth was ashed and the residue was extracted with 30 ml of dil hydrochloric acid. The extract was passed through a column (diam. 1.2cm) filled with strong base anion-exchange resin (AG 1-X8, 100-200 mesh, Cl- form, 8g) and lead was eluted with 70ml of 8N hydrochloric acid. The effluent was concentrated and lead was determined by the ordinary dithizone method. The analytical results from model lipstick (20% BiOCl) containing about 40 ppm of lead showed little variation and good reproducibility. The coefficient of variation was 3.3%. The lead content of commercial lipstick containing various quantities of BiOCl was less than 5 ppm in each by this method.
