GC Determination of 13 Dyes and Impurities in Hair Colorants

A method of GC for simultaneous determination of 13 dyes, including phenol, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, o-dihydroxybenzene, m-dihydroxybenzene, p-dihydroxybenzene, m-aminophenol, p-aminophenol, 2,6-diamino-pyridine, 2-methylresorcinol, 5-amino-2-methylphenol and 3,4-diamino-methylbenzene in hair colorants was proposed. The 13 dyes in sample were ultrasonically extracted with ethyl acetate, separated on HP-5 capillary chromatographic column (30 m×0.32 mm, 0.25 μm) and detected by flame ionization detector (FID). Linearity ranges for the 13 dyes were found in the same range of 10-500 mg·L-1, with detection limits (3S/N) less than 1 mg·L-1. Tests for recovery were carried out at three concentration levels of 50, 100 and 200 mg·L-1, giving values of recovery in the range from 85.4% to 103.5% and RSD′s (n=6) in the range from 1.2% to 5.2%.