Abstract
A new simple method for the determination of dyes (erythrosine, rhodamine B, tetrachloromofluorescein, deep maroon, eosine YS, permanent orange, lake red CBA) in lip sticks was studied.
The lip stick was dissolved in a few milliliter of chloroform and filled up with ethanol (erythrosine, rhodamine B, eosine YS, tetrachlorotetrabromofluorescein), acidic ethanol (lake red CBA, deep maroon) or 1, 1, 2-trichloroethane (permanent orange). The coloring materials were separated by thin-layer chromatography. Ethanol, mixed solvents of petroleum ether: toluene: chloroform (1:2:3) or n-buthanol: ethanol: 0.5N acetic acid (6:2:3) were used for the chromatog raphy. After the thin-layer chromatographic separation, each spot on the thin-layer chromatogram was scanned dy a dual wave length densitometer under visible ray.
The coefficients of variation of dual wave length densitometer were 0.85-1.74%. The recoveries of dyes added into lip stick were 90.9-102.4%.
