Simultaneous determination of non-steroidal anti-inflammatory drugs in river water samples by liquid chromatography–tandem mass spectrometry using molecularly imprinted polymers as a pretreatment column

A restricted access media-molecularly imprinted polymer (RAM-MIP) for flufenamic acid has been developed for the simultaneous determination of non-steroidal anti-inflammatory drugs (NSAIDs) in river water samples. The RAM-MIP was prepared using 4-vinylpyridine and ethylene glycol dimethacrylate as a functional monomer and cross-linker, respectively, by a multi-step swelling and polymerization method followed by a surface modification technique. The RAM-MIP for flufenamic acid showed excellent molecular recognition abilities for flufenamic acid and mefenamic acid, and moderate molecular recognition abilities for indomethacin, etodolac and ketoprofen. The simultaneous determination of NSAIDs (mefenamic acid, indomethacin, etodolac and ketoprofen) in river water samples was carried out by LC–MS/MS using the RAM-MIP for flufenamic acid as a pretreatment column. The concentrations of mefenamic acid, indomethacin and etodolac in river water samples were determined to be 0.4, 0.7 and 0.3 ng/L, respectively, while ketoprofen was below the limit of quantitation.