GC-MS Analysis of Ambergris Extracts

Extracts were analysed using a Thermo Fisher Trace 1310 gas chromatograph coupled to a Thermo Fisher Quantum XLS Ultra mass spectrometer (ThermoFisher Scientific, Waltham, Massachusetts, USA). A ZB-5ms (Phenomenex, Torrance, USA), 30 m fused silica capillary column, 250 µm i.d. with a film thickness of 0.25 µm was used with helium (BIP^® ECD) as carrier gas at a constant flow of 1.5 mL min⁻¹. The ambergris extract was injected in split mode 20:1; all other samples were injected splitless. The injection volume was 1 µL. The injection port was raised from 80 °C to 300 °C at 14.5 °C s⁻¹. The column temperature was kept at 80 °C for 1 min, then increased to 310 °C at 5 °C min⁻¹ where it was kept for 20 min. Solvent delay for filament activation of the ion source was set at 20 min and electron ionization voltage was set at 70 eV. The scanning mass range was m/z 50–600. Steroids and ambrein were identified according to their TMS-mass spectra published in the literature^{3 (link),19 ,29 (link)}, the NIST 05 Mass Spectral Search Program and by comparing mass spectra and elution order with steroid analytical standards (from Sigma Aldrich (Germany) and Chiron (Norway)) for coprostanol, epicholestanol, epicoprostanol, 5α-cholestanol and cholesterol.