Magnetic graphene oxide nanocomposite materials for magnetic dispersive solid-phase extraction and determination of pyrrolizidine alkaloids in tea beverages

Pyrrolizidine alkaloids (PAs) and their N -oxides (PANOs) are plant-derived toxins, and tea beverages represent one of the most important exposure pathways of PAs/PANOs for human being. Therefore, establishing a method for the sensitive determination of PAs/PANOs is of great significance. In this study, magnetic graphene oxide (MGO) nanocomposite materials were used as an adsorbent in magnetic dispersive solid-phase extraction (d-MSPE) for quantifying PAs/PANOs in tea beverages. MGO exhibited high adsorption efficiency of PAs/PANOs from 83 % to 99 %, with rapid adsorption occurring within 20 min and desorption taking only 6 min. Under optimized conditions, the method showed excellent linearity (1–500 μg/L), low detection limits (0.01–0.6 μg/L), and good precision (RSD < 9.4 %). These results demonstrate the d-MSPE is a simple, efficient, and rapid method for the sample pretreatment and determination of PAs/PANOs in tea beverages.