Abstract
Studies on the ion-paired extraction method for various dyes in cosmetics with quaternary amine are described.
Sulfonic and carboxylic groups in dye molecule contained in cosmetics, reacted stoichmet-rically with tetra-n-octyl ammonnium hydroxide to form dye-amine complex, and then which was easily able to extract with organic solvent.
Free dyes were reextracted from dye-amine complex in organic layer to waterr layer by using sodium tetraphenyl borate.
The determination of dye in water layer was developed by use of high-performance liquid chromatography.
By this method recoveries of dyes from lip stick were not less than 80%.
