An Improved Method for Analysis of Oxidation Dyes in Human Hair

An improved method for selected ion monitoring analysis of oxidation hair dyes in human hair is described. Ten centimeter of hair specimen, stained with oxidation hair dye which was left for three months, was dissolved in 0.3 ml of 3N-NaOH solution containing 50 mg of sodium hydrosulfite. Then, the diamines (p-phenylenediamine [PPDA], toluene-2,5-diamine [T-2,5-DA]) were directly extractd with diethyl ether from the degraded hair solution. Aminophenols (o-aminophenol [OAP], m-aminophenol [MAP], p-aminophenol [PAP]) were extracted with diethyl ether from the aqueous layer neutralized with 3N-acetic acid. Both extracts were devivatized with pentaflourobenzaldehyde and analyzed by GC/MS. Though PPDA, T-2,5-DA, OAP, MAP and PAP were not separated by previously repoted method, these five main components of oxidation hair dyes were separated from each other and identified. By this method, MAP could be clearly separated from PAP.