Magnetic metal–organic framework nanocomposites for enrichment and direct detection of small molecules by negative-ion matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Fe₃O₄@ZIF-8 MNCs were proposed as an absorbent and a new matrix for negative ion MALDI-TOF MS, which exhibited interference-free background, good reproducibility and sensitivity for analysis of small molecules.