HPLC Determination of 11 Dyes in Oxidative Hair Colorants

HPLC was applied to the determination of 11 dyes in oxidative hair colorants. The sample was extracted with mixture of methanol and H2O (1+1). The extract was separated on Capcell Pak C18 MG S5 column (250 mm×4.6 mm,5 μm) by gradient elution with mixture of acetonitrile and triethylamine (adjusted to pH 7.7 with phosphoric acid) mixed in the ratio of 3 to 97, and determined with photodiode array detector at the wavelength of 280 nm. Linearity ranges for 11 dyes were found between 20-500 mg·L-1. Using blank sample of hair colorants as matrix, test for recovery was made by standard addition method, values of recovery found were in the range of 70%-110% with RSD′s (n=6) less than 10%.