A 3-step load-wash-elute solid-phase extraction tandem dedicated clean-up cartridge prior to UPLC-MS/MS for the simultaneous determination of bongkretic acid, isobongkretic acid and toxoflavin in edible mushrooms and rice noodles.

A 3-step load-wash-elute solid-phase extraction tandem dedicated clean-up cartridge prior to UPLC-MS/MS for the simultaneous determination of bongkretic acid, isobongkretic acid and toxoflavin in food is presented in this work. The 3-step load-wash-elute SPE strategy with PRiME HLB, eliminating conditioning and equilibration, and coupled with dedicated purification cartridge, PriboFast MFC 336, was used as a tandem cartridge for sample pretreatment. Various sample pretreatment conditions including sample extractant, the tandem cartridge, the optimizatioin of PRiME HLB SPE conditions and PriboFast MFC 336 purification conditions, as well as MS/MS conditions and HPLC conditions were systematically investigated. Under the optimal experimental conditions, high sensitivity (LODs: 0.030-0.040 μg kg, LOQs: 0.090-0.12 μg kg), acceptable recoveries (83 %-96 %) and good precisions (r < 6.0 %) were obtained. The method was successfully applied to 90 food samples, bongkretic acid and isobongkretic acid were detected simultaneously in a dried black fungus, whereas toxoflavin was not detected in any of the samples.