Covalent organic framework-graphene oxide composite: a superior adsorption material for solid phase microextraction of bisphenol A

Abstract Novel materials with high adsorption and desorption efficiencies are significant for studying compounds at ultra-trace level. Herein, covalent organic framework-graphene oxide (COF-GO) composite materials are synthesized, and tested for solid phase microextraction (SPME) of bisphenol A (BPA) at ultra-trace level. With GO modified successively by 3-aminopropyltriethoxysilane, 1,3,5-triformylphloroglucinol (Tp), and different ratios of COF monomers (Tp and benzidine (BD)), the composites of TpBD-GO-n (n = 1∼4) are synthesized. By coating the composites on a glass fiber, the extraction performances of the composites for BPA are tested with constant flow desorption ionization mass spectrometry (CFDI-MS). The extraction efficiency of the composite TpBD-GO-2 is 2.2 and 4.7 times higher than those of TpBD and GO, respectively. The chromatographic separation becomes a non-essential step for detection of BPA, the analysis time for each sample is reduced to 8 min. The limits of detection and quantification of MS for BPA analysis are improved to be 22.2 and 73.9 ng L–1. The linear range is extended to be 10.0 μg L–1 (R2=0.9990), and the relative standard deviations of one fiber (n = 11) and fiber-to-fiber (n = 8) are 4.3 % and 5.6 % (1 μg L–1), respectively. With this method, ultra-trace levels of BPA present in river water and sea water samples can be successfully detected and quantified. The results indicate that the TpBD-GO-n composites possess superior extraction performance, and their various applications could be expected.