A magnetic MOF derivative with rich interactions formed under mild preparation conditions for the extraction of non-steroidal anti-inflammatory drugs from the Yellow River.

For sorbents, good magnetic properties and rich interactions with targets are important ways to improve the efficiency of magnetic solid-phase extraction (MSPE). The magnetic MOF-101 derivative (MD) was obtained by heat-treating MOF-101 at different temperatures. After a series of characterizations, it was found that MD-350 had the best magnetic properties and retained more functional groups of the original MOF-101, and had better extraction efficiency as compared to MD obtained under other treatment temperatures for the MSPE of four non-steroidal anti-inflammatory drugs (NSAIDs) in water samples, coupled with high-performance liquid chromatography (HPLC). The remaining functional groups of MD-350 can produce more interactions with NSAIDs, such as hydrogen bonding, π-π conjugation, and coordination interactions; good magnetic properties facilitate the separation of the sorbent and the solution. These advantages indicate that the established extraction method demonstrated satisfactory extraction performance: an excellent recovery rate (96.73-100.61%) with a short extraction time (15 min), a wide linear range (4-400 μg L-1) with a determination coefficient of 0.9975-0.9993, a low LOD of 0.2-0.5 μg L-1 and up to 12 times service-life without the loss of the recovery rate. Satisfactory results were also obtained in extracting NSAIDs from Yellow River. All these results indicate that MD-350 prepared under mild conditions has potential as an MSPE sorbent to detect and remove NSAIDs from environmental waters with high efficiency and long service life.