Mechanochemically synthesized zeolitic imidazolate framework-8 as sorbent for dispersive solid-phase extraction of benzophenone-type ultraviolet filters in aqueous samples.

Benzophenone-type ultraviolet filters (BP-UVFs) are a group of emerging contaminants, which found in various environmental aqueous samples raising potential risks for public health concern and could bioaccumulate in the food chain. This study describes a simple and "green" method to rapidly analyze five BP-UVFs that are frequently found in surface water and in seawater samples. Dispersive solid-phase extraction (DSPE) using a zeolitic imidazolate framework‑8 (ZIF-8) as the sorbent was applied to efficiently extract the BP-UVFs from aqueous samples, and they were then detected and quantified by UHPLC-electrospray ionization (+)-quadrupole time-of-flight mass spectrometry (UHPLC-ESI (+)-QTOF-MS). The ZIF-8 sorbent was synthesized by a green one-step mechanochemical process using water-assisted grinding and a stoichiometric reaction. The Box-Behnken Design coupled with the response surface method was applied to optimize the main DSPE extraction factors. The developed method was fully validated, showing low limits of quantification (LOQs; 0.3-20 ng L), satisfactory mean spiked recoveries (72-105%), and a high level of precision (3-9%). A preliminary analysis of the surface water and seawater samples revealed that 2-hydroxy-4-methoxybenzophenone (BP-3) was the most common BP-UVF present in our aquatic environment, likely due to its widespread applications and slow rate of degradation.