Abstract: A method using a new online purifying pretreatment system and high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the determination of ergosterol and ergotsterone in food flavors and spices. The pretreatment method in combination with matrix solid-phase dispersion and column chromatography was used for sample extraction and purification, followed by concentration and analysis by HPLC-MS/MS. The analysis was performed on a C18 column with gradient elution with a mobile phase consisting of water and methanol at a flow rate of 0.4 mL/min. The mass spectrometer with an?atmospheric pressure chemical ionization (APCI) source in the positive ion mode was operated using multiple reaction monitoring (MRM) and an internal standard method was used for quantification. The results showed that the pretreatment method was simple and stable with solvent recycle, integrating extraction, purification and concentration. The two analytes could be separated in 5 min with good linearity in the concentration range of 1.5–250 μg/mL with correlation coefficients larger than 0.999. The limits of detection (LODs) were 0.32 μg/mL for ergosterol and 0.35 μg/mL for ergotsterone. The mean recoveries of the target compounds at three different spiked levels were 86%–96% with relative deviations (RSDs) of 3.1%–3.6%. This method is suitable for the analysis of ergosterol and ergotsterone in food flavors and spices.

Key words: ergosterol, ergotsteron, online purification pretreatment, HPLC-MS/MS, flavors and spices