Identification of reaction products of methamphetamine and hydrogen peroxide in hair dye and decolorant treatments by high‐performance liquid chromatography/mass spectrometry

The effect of hydrogen peroxide, a main component of hair dye and decolorant treatments, on methamphetamine (MA) was studied. Two analytical methods, thin‐layer chromatography (TLC) and high‐performance liquid chromatography/mass spectrometry (LC/MS), were used for the separation and identification of MA derivatives. Mixtures of MA solutions and hydrogen peroxide that had been incubated at 39°C for 24 h were shown to contain para‐hydroxy MA by TLC and para‐, meta‐ and ortho‐hydroxy MAs by LC/MS. In addition, MA N‐oxide and N‐hydroxy MA were found in MA/hydrogen peroxide mixtures immediately after mixing. Therefore, we concluded that MA changed to MA N‐oxide and N‐hydroxy MA before changing to para‐, meta‐ and ortho‐hydroxy MAs.