High-surface β-Ketoenamine linked covalent organic framework driving broad-spectrum solid phase microextraction on multi-polar aromatic esters

Aromatic esters have been widely used in daily life with non-ignorable dangers, such as plasticizer, flavor, and preservative. Their wide applications and corresponding hazards caused by overuse have promoted the rapid development of sensitively analytical method for effective regulation. However, the variety makes it challenging for broad-spectrum and simultaneous extraction of diverse aromatic esters from the highly complex cosmetic samples. To our delight, a covalent organic framework, named DaTp (1, 3, 5-triformylphloroglucinol-2, 6-diaminoanthracene), possessing high specific surface, excellently thermochemical stability, and abundant electron-rich heteroatoms, has been synthesized and fabricated as a competitive solid phase microextraction coating for extracting the trace analytes with diverse polarity, through the hydrophobic interaction, π-π conjugation and hydrogen bond. Herein, this self-made SPME fiber has been further coupled with gas chromatography-tandem mass spectrometry (GC-MS) to determine the multi-polar aromatic esters in cosmetics packaged with plastic. This developed analytical method showed wide liner ranges, low limits of detection, good repeatability and reproducibility. Finally, the aromatic esters in four cosmetic samples were quantified precisely with satisfactory recoveries (80.7%-118%).