Graphene/polydopamine-modified polytetrafluoroethylene microtube for the sensitive determination of three active...

Determination of bioactive compounds in traditional Chinese medicines and biological samples is usually interfered with by coexisting components in matrices. In this work, we prepared novel multilayer functional graphene/polydopamine-modified polytetrafluoroethylene microtube for selective solid-phase microextraction of three bioactive compounds in Fructus Psoraleae. Functional graphene/polydopamine-modified polytetrafluoroethylene microtube showed good extraction efficiency toward bavachin, isobavachalcone, and bavachinin; enrichment from 357- to 737-fold was obtained for these compounds. For qualitative analysis, an online solid-phase microextraction with high-performance liquid chromatography method was developed, which showed low limits of detection of 0.02 ng/mL by using UV detection, which is significantly more sensitive than previously reported methods. The proposed method has been used to determine bavachin, isobavachalcone, and bavachinin in Fructus Psoraleae, the contents of three compounds were quantified to be 64.0, 324.0, and 384.5 μg/g; recoveries were 93.4-101.1%. The proposed method has also been applied to determine bavachin, isobavachalcone, and bavachinin in rat plasma samples after oral administration of Fructus Psoraleae.