Solid-phase analytical derivatization of alkylphenols in fish bile for gas chromatography–mass spectrometry analysis

Solid-phase analytical derivatization (SPAD) with bis(trimethylsilyl)trifluoroacetamide (BSTFA) has successfully been used as a sample preparation method for determination of (APs) in fish bile treated with β-glucuronidase and sulfatase. Derivatized APs were analysed by gas chromatography–mass spectrometry in the electron ionization mode (GC–EI-MS). Overall limits of detection (LODs) ranged from 5 to 18 ng/g bile for 19 out of 21 investigated compounds. LODs were not determined for 4-methylphenol and 4-tert-octylphenol due to high background levels in control bile. Recoveries ranged from 83 to 109%. The analysed APs vary in degree of alkylation from methyl (C1) to nonyl (C9), and represent various pollution sources, including produced water (PW) discharge from the offshore oil industry. The applicability and sensitivity of the method has been demonstrated by analysis of bile taken from Atlantic cod (Gadus morhua L.) exposed to two dilutions of PW (1:500 and 1:1500) in a continuous flow system.