Covalent organic frameworks-based paper solid phase microextraction combined with paper spray mass spectrometry for highly enhanced analysis of tetrabromobisphenol A

Abstract

How to further improve the sensitivity of paper spray mass spectrometry (PS-MS) is very important for its application in low content substance detection. Covalent organic frameworks (COFs) are a kind of novel crystalline materials that exhibit tremendous potential for multifarious applications. Nevertheless, the applications of COFs in PS-MS are still unexplored. Herein, for the first time, a method that used COFs nanoparticles as a coated matrix of PS-MS coupled with solid phase microextraction (SPME) was developed, and as a proof of concept, it was applied for highly sensitive analysis of pollutant tetrabromobisphenol A (TBBPA) in environmental samples. In order to prepare the COFs-coated papers, a variety of factors, such as starch type and amount, loaded COFs amount and spray solvent, have been explored in detail. Compared with the naked paper substrates, a lower limit of quantitation of 1 nmol L⁻¹ with 50-fold enhancement was achieved using COFs-based paper composites, which indicated that papers decorated with COFs might be a promising candidate for paper spray with high sensitivity in the analysis of environmental samples.