Simultaneous enantiomeric analysis of chiral non-steroidal anti-inflammatory drugs in water, river sediment, and sludge using chiral liquid chromatography-tandem mass spectrometry

A sensitive and reliable analytical method for the simultaneous enantiomeric analysis of chiral non-steroidal anti-inflammatory drugs (ibuprofen, ketoprofen, and flurbiprofen) in water, river sediment, and sludge was established. Enantioseparation of the analytes was performed on a Chiralpak IG column using a mobile phase of 0.1% aqueous formic acid and acetonitrile. Magnetic solid-phase extraction, based on dummy-template molecularly imprinted polymer-coated magnetic multi-walled carbon nanotubes combined with dispersive liquid-liquid microextraction, was employed to pretreat complex environmental samples. Parameters affecting the extraction efficiency of the pretreatment processes were systematically optimized. Under the optimized conditions, recoveries of all enantiomers from environmental matrices were in the range 75.8-92.1% with relative standard deviations no higher than 12.4%. The quantification limits for enantiomers ranged from 6.17 to 11.94 ng L-1 in water samples and from 1.16 to 2.54 ng g(-1) in river sediment and sludge samples. This method was successfully used to analyze the enantiomeric composition of three chiral non-steroidal anti-inflammatory drugs in real environmental samples, which will improve understanding of their degradation processes and aid evaluation of their ecological toxicity.