Simultaneous determination of fifteen toxic alkaloids in meat dishes and vegetable dishes using double layer pipette tip magnetic dispersive solid phase extraction followed by UFLC-MS/MS

A novel double layer pipette tip magnetic dispersive solid phase extraction (DPT-MSPE) based on polyamidoamine-functionalized magnetic carbon nanotubes (PAMAM@Mag-CNTs) was developed for the purification of fifteen toxic alkaloids in meat dishes and vegetable dishes. PAMAM@Mag-CNTs were synthesized through direct reaction between the carboxy group on the surface of the Mag-CNTs and the peripheral amino group of the polyamidoamine (PAMAM) dendrimers. The magnetism of PAMAM@Mag-CNTs simplified the post-processing during preparation of the sorbent, and reinforced the interaction between the sorbents and the analytes during the cleanup procedure. An ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) coupled with DPT-MSPE method has been developed to determine fifteen alkaloids in meat dishes and vegetable dishes. Under the optimal conditions, satisfactory recoveries, i.e., 83.4–125% for meat dishes and 84.2–122% for vegetable dishes, were obtained due to the high cleanup efficiency of the DPT-MSPE. Furthermore, the method, which displays good linearity (r ≥ 0.9991), acceptable precision (RSD < 8%), and low limits of quantification (0.054–1.058 ng g−1), has been successfully applied to several food samples, and it was confirmed that PAMAM@Mag-CNTs DPT-MSPE was a highly effective extraction method for alkaloids in cooked food samples.