Abstract: As a new two-dimensional graphene analogue, graphitic carbon nitride (g-C3N4) shows great potential for separation science and sample pretreatment techniques. g-C3N4 has excellent properties such as ultra-high hardness, low density, good biocompatibility, surface modifiability and strong adsorption affinity. The structure and surface physicochemical properties of g-C3N4, related to its absorption behavior, are mainly depended on the preparation and adsorption conditions. The N-rich functional groups and electronic delocalization properties endow g-C3N4 with a complex absorption mechanism involving complexion, hydrogen bonding, redox reaction, π–π conjugation, hydrophobic effect, acid-base reaction and electrostatic interaction. At present, g-C3N4 has been applied in sample pretreatment techniques including solid-phase extraction, magnetic solid-phase extraction, and solid-phase microextraction for food analysis. In order to improve the knowledge of its superior properties and facilitate its applications as a sorbent in sample pretreatment for food analysis, the structure, properties, and adsorption mechanism of g-C3N4 are reviewed in this article.

Key words: sample pretreatment;?graphitic carbon nitride; structure and properties; adsorption mechanism