A Covalent Organic Framework-Derived Hydrophilic Magnetic Graphene Composite as a Unique Platform for Detection of Phthalate Esters from Packaged Milk Samples

The development of functional nanocomposites based on covalent organic framework (COF) is still highly important. In this work, a novel COF-functionalized hydrophilic magnetic graphene (magG@PDA@TbBd) was prepared through a facile and efficient route and applied as a unique magnetic solid-phase extraction matrix for phthalate esters analysis. The obtained magG@PDA@TbBd exhibited excellent water dispersibility, large surface area, strong magnetic response, regular mesoporous structure and strong - electron system. Based on these properties, the newly prepared composite displayed outstanding reusability and potential performances on phthalates analysis with good linearity (50-8000ngmL(-1)) and reliable recoveries (91.4-105.2%). Limit of detection (LOD) varied from 0.004ngmL(-1) to 0.02ngmL(-1), and relative standard deviation (RSD) for intra-day and inter-day were less than 4.4% and 6.7%, respectively. More interestingly, the newly obtained magG@PDA@TbBd was utilized to analyze 9 PAEs in packaged milk samples. This work may open-up a direction in design and construction of functionalized COF-derived composites.