Identification of Illegal Coal Tar Dyes Constituents in Mucous Cosmetics by HPLC Method
KUN-SHAN WU1,2, AN-BANG WU1, MING-CHUAN HUANG2 AND CHAU-YANG CHEN1*
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Graduate Institute of Pharmaceutical Science, Taipei Medical College, 250 Wu -Hsing Street, Taipei, Taiwan 110, R.O.C
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National Laboratories of Foods and Drugs, Department of Health, Executive Yuan, Taiwan 115, R.O.C.
ABSTRACT
Illegal coal tar dyes are reported to possess strong toxicity and carcinogenecity when added in mucous cosmetics. According to CNS, current methods in analyzing organic coloring materials (dyes) are mainly filter paper chromatography and thin-layer chromatography. In this study, we adopted a refined HPLC procedure reaching optimal conditions for the separation and identification of the coloring constituents allegedly added in mucous cosmetics. Ultimately, the analytical efficiency and precision are greatly improved. The optimal conditions for the HPLC method were found with a column of Cosmosil 5C18-AR-II; with the first mobile phase using 0.07 M ammonium acetate solution in 0.01 M tetrabutylammonium bromide (CH3COONH4) : CH3CN : CH3OH = 55:35:10 for analyzing 16 hydrophilic coal tar dyes, while the second mobile phase uses CH3OH : H2O = 95:5 for analyzing 6 hydrophobic dyes and a photodiode array detector within UV-VIS wavelength. By applying this HPLC method, a total of 22 banned coal tar dye constituents can be satisfactorily separated. It is also found that the detection limit can be improved to 0.05 μg/mL.
Key words: high performance liquid chromatography (HPLC), illegal coal tar dyes, mucous cosmetics