Determination of the food carcinogen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in human hair by solid-phase extraction and gas chromatography-mass spectrometry

A method for the determination of the food mutagen 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in human hair has been developed and validated. Hair samples (200 mg) were dissolved in NaOH (1 M) and PhIP was isolated by successive solid-phase extraction on a polystyrene - divinylbenzene column and on a silica-based mixed-mode column with C-8 and - SO3- functional groups. Quantification was performed by gas chromatography - electron-impact ionization high-resolution mass spectrometry in selected-ion-monitoring mode. The method was validated for determination of PhIP in the concentration range 0.5-2.5 ng g(-1) hair with [H-2(3)]PhIP as internal standard. The limit of quantification was 0.26 ng g(-1) hair. Within-day and between-day precision were in the ranges 1 - 27% and 2 - 15% relative Standard deviation, respectively. The hair sample used for method validation was found to contain 0.26 ng PhIP g(-1) hair.