| An ion-pair high performance liquid chromatographic method was established to simultaneous determination five dyes in oxidized hair dyes. The chromatographic conditions were as follows: Phenomenex kinetex C18 column ( 2.6 μm, 4.6 mm × 150 mm ) was selected, with 10 mmol/L Octanesulfonic acid sodium solution ( pH 2.5 ) methanol ( 60∶40, V/V) as the mobile phase, a diode array detector was used, detection wavelength at 280 nm, qualitative analysis by retention time and UV spectra characteristics, quantitative analysis by external standard method. Results showed good linearity for the 5 compounds ranging from 20.0 mg/L to 100 mg/L, lowest detective limits for Quinhydrone is 0.02%, Resorcinol is 0.03%, o-aminophenol is 0.02%, o-phenylenediamine is 0.04%, 4-amino-2-hydroxytoluene is 0.03%. Average spiked recoveries of matrices at lower level were between 82.5% and 106%,with RSD between 1.4% and 6.1%. Average spiked recoveries of matrices at middle level were between 82.0% and 105%,with RSD between 0.4% and 2.2%. Average spiked recoveries of matrices at high level were between 78.5% and 105%,with RSD between 1.7% and 4.5%. |
