Solid phase extraction based on a coral like structure conjugated microporous polymer for the detection of preservatives in milk and water.

In this study, a coral like structure conjugated microporous polymer with abundant N/O functional groups was synthesized using a one-step method. The synthesized material was assembled into a solid-phase extraction (SPE) column, and it showed efficient extraction performance for paraben-based preservatives. Under optimized SPE conditions, a high performance liquid chromatographic (HPLC) method with good linear (r≥0.998), low detection limit (0.07-0.19 ng/mL) and high precision (1.8-6.7%, n=6) was developed. The applicability of this method was evaluated by analyzing real samples (milk and water), with spiked recovery rates ranging from 82.8% to 106%, further confirming the accuracy and reliability of the method. The adsorption mechanism was also discussed by simulation calculations, and it was mainly dominated by hydrogen bonding, π-π interactions and van der Waals forces.