One-step in-syringe ionic liquid-based dispersive liquid–liquid microextraction

Dispersive liquid–liquid microextraction (DLLME) has been proved to be a powerful tool for the rapid sample treatment of liquid samples providing at the same time high enrichment factors and extraction recoveries. A new, simple and easy to handle one step in-syringe set-up for DLLME is presented and critically discussed in this paper. The novel approach avoids the centrifugation step, typically off-line and time consuming, opening-up a new horizon on DLLME automation. The suitability of the proposal is evaluated by means of the determination of non-steroidal anti-inflammatory drugs in urine by liquid chromatography/ultraviolet detection. In the presented approach an ionic liquid is used as extractant. The target drugs can be determined in urine within the concentration range 0.02–10 μg mL−1, allowing their determination at therapeutic and toxic levels. Limits of detection were in the range from 8.3 ng mL−1 (indomethacin) to 32 ng mL−1 (ketoprofen). The repeatability of the proposed method expressed as RSD (n = 5) varied between 2.5% (for ketoprofen) and 8.6% (for indomethacin).