Development of a novel second-generation polyester dendritic functionalized graphene oxide for efficient pipette tip micro solid-phase extraction and detection of venlafaxine and desvenlafaxine in urine

A novel adsorbent, second-generation polyester dendritic functionalized graphene oxide (PDG-2), was developed for pipette tip micro solid-phase extraction of venlafaxine and desvenlafaxine from urine. Leveraging the facile modification properties of graphene oxide and the controlled synthesis capabilities of dendritic materials, PDG-2 exhibited a rough surface and numerous active groups with adsorption capacities of desvenlafaxine and venlafaxine up to 187 mg g(-1) and 230 mg g(-1) . Method validation confirmed excellent linearity, low detection limits, high precision, and accurate recovery. Compared with commercial adsorbents, PDG-2 outperformed HLB and MCX and matched the performance of C 18 with a much smaller amount.