An efficient and rapid thin-layer chromatography method for the identification of 32 dye substances in hair dye products

Objective: The use of dye substances in hair dye products has led to controversial public and scientific discussions about their impact on human health. This study aimed to explore a rapid method for identification of dye substances in hair dye products.

Methods: Thin layer chromatography (TLC) method was conducted in this study. We developed basic data of 32 dye substances by 4 developing solvents and 2 indicator sprays. The dye substances were identified by comparing the Rf values and colors between samples and reference substances.

Results: Thirty samples were identified by the established method. 22 hair dye substances were detected in 16 formula known samples, 15 hair dye substances were detected in 14 formula unknown samples. Four laboratories participated in the validation and the results showed good interlaboratory reproducibility.

Conclusion: The developed TLC method is simple, rapid, reliable and can be finely used for identification of dye substances in hair dye products.