PEG modified column MIL-101(Cr)/PVA cryogel as a sorbent in stir bar solid phase extraction for determination of non-steroidal anti-inflammatory drugs in water samples

In this study, poly(ethylene glycol) (PEG) acted as the porogen to increase the adsorption capacity of the composite MOFs/PVA cryogel. The characterization results demonstrated that the BET surface area of PEG modified MIL-101(Cr)/PVA cryogel obviously increased. The factors influencing the extraction efficiency, such as the ratio of PVA/PEG, the amount of MIL-101(Cr), pH adjustment, effect of salt, extraction and elution time and elution solvent, were studied. MIL-101(Cr)/PVA/PEG cryogel was used as a SB-SPE sorbent for the extraction of five non-steroidal anti-inflammatory drugs (NSAIDs) in environmental water samples. A satisfactory result of methodology validation was obtained. Under the optimum condition, good sensitivity levels were achieved with the limit of detection between 0.011 and 0.035 mu g/L, and the analytical method showed good linearity in the range of 0.10-10 mu g/L for ketoprofen, naproxen, diclofenac and carprofen and 0.05-5 mu g/L for mefenamic acid (r(2) >= 0.9912). The relative recoveries of the target analytes were in the range from 77.41% to 102.3% with relative standard deviation (RSD) from 1.67% to 9.52%. The MIL-101(Cr)/PVA/PEG composite cryogel has an environmentally friendly fabrication process and higher adsorption capacity comparing with the previously fabricated MIL-101(Cr)/PVA cryogel.