Assessment of semi-permanent hair dyes in wash water from beauty salons by liquid chromatography-tandem mass spectrometry reaction monitoring (LC-MS/MS-SRM)
Herein, we present an approach for the analytical determination and quantification of semi-permanent hair dyes in wash water samples released during washing of dyed hair employing liquid chromatography-tandem mass spectrometry-selected reaction monitoring (LC-MS/MS-SRM) method with electrospray ionization detection. Specifically, Basic Blue 99 (BB 99), Basic Brown 16 (BB 16), Basic Red 76 (BR 76), Basic Yellow 57 (BY 57) and Acid Violet 43 (AV 43) are hair dyes with known harmful properties to human and environment health. They are usually present in the commercial formulations and discharged without restrict legislation. The detection and quantification by LC-MS/MS technique show linear relationship for each studied hair dye in the concentration range from 1 to 200 ng mL-1 in aqueous solution. The limits of detection and quantification were found from 0.66 to 20 ng mL-1 and from 2.0 to 63 ng mL-1, respectively, values that are compatible with the level required in wash water analysis. The method was applied in the samples collected from 5 successive washings of the dyed hair with a commercial formulation using the established procedure. BB 99 and BY 57 dyes have lower fixation on the scalp and hair showing 866 ng mL-1 and 145 ng mL-1 releasing on the first day of washing, respectively. The accumulation of dye and low release after washing can lead to future problems for both environment and living organisms.