Determination of 4-amino-m-cresol and 5-amino-o-cresol by high performance liquid chromatography and fluorescence derivatization using fluorescamine.
For the determination of two oxidation hair dyes, 4-amino-m-cresol (4-AC) and 5-amino-o-cresol (5-AC), a sensitive isocratic high performance liquid chromatography (HPLC) method using the reversed phase mode was developed. The hair dyes were pre-column derivatized with fluorescamine prior to injection. Sensitivity could be improved 10-fold for 4-AC and 50-fold for 5-AC by fluorescence detection compared to UV detection. The limit of detection was 1 ng/injection for 4-AC and 100 pg/injection for 5-AC, respectively. For the determination of both compounds in aqueous biological matrices in order to simulate conditions for penetration studies with pig skin, a solid phase extraction procedure using C18 cartridges and acetonitrile (ACN) for elution could be developed. Average recovery was 83.4% with a coefficient of variation (CV) of 2.64% for intra-day assay and 3.20% for inter-day assay for 5-AC and 2.89% and 3.41% for 4-AC, respectively.
Eggenreich
K
K
Institute of Pharmaceutical Chemistry and Pharmaceutical Technology, Karl-Franzens-University, Schubertstrasse 1, A-8010 Graz, Austria.
Zach
E
E
Beck
H
H
Wintersteiger
R
R
D000818:Animals; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003408:Cresols / Q000032:analysis* / Q000493:pharmacokinetics*; D006202:Hair Dyes / Q000032:analysis* / Q000493:pharmacokinetics*; D008657:Metabolic Clearance Rate; D012867:Skin / Q000378:metabolism*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013552:Swine
D003408:Cresols; D006202:Hair Dyes