Synthesis of N‑doped carbon nano‑onion‑zirconium‑based metal–organic framework composite and its application in dispersive micro‑solid‑phase extraction of patulin from apple juice followed by HPLC analysis

Synthesis of N-doped carbon nano-onion-zirconium-based metal–organic framework composite and its application in dispersive micro-solid-phase extraction of patulin from apple juice followed by HPLC analysis