An in situ modification sorbent for magnetic dispersive micro solid-phase extraction of anti-inflammatory drugs in the human urine sample before their determination with high-performance liquid chromatography

Dispersive micro solid-phase extraction is a sample preparation procedure under the principles of green chemistry with the need for a small sample solution, little sorbent, low desorption solvent, and a proper extraction time. A selective and straightforward microextraction procedure based on dispersive micro solid-phase extraction was introduced to simultaneously separate and preconcentrate three nonsteroidal anti-inflammatory drugs such as naproxen, diclofenac, and paracetamol in human biological samples. The sorbent was prepared using Fe3O4/GO nanocomposite as a sorbent magnetic core, modified with a cationic surfactant (cetyl trimethyl ammonium bromide) through an in situ physical modification. In the procedure, the sorbent surface modification and analyte extraction were performed at one step in the sample solution, leading to a simple sorbent modification and reduced analyte determination. The Influential parameters on the extraction of the nonsteroidal anti-inflammatory drugs were optimized based on one factor at a time technique. The procedure showed proper linearity of 0.015-100.0, 0.015-150.0, and 0.12-150.0 mu g mL(-1) for the determination of paracetamol, naproxen, and diclofenac in water samples with an excellent R-2 (>= 0.9937) and suitable enrichment factors (>= 69.4), respectively. Besides, the detection limit and quantitation limit for the drug measurement were lower than 0.04 and 0.12 mu g mL(-1), respectively. Intra- and inter-day RSDs for five times determinations of naproxen, diclofenac, and paracetamol with three concentrations of 1.0, 10.0, and 50.0 mu g mL(-1) were determined and were in the ranges of 3.15-4.01% and 4.97-6.94%, respectively. Under the optimal conditions, the procedure was utilized to analyze human urine samples, indicating high recoveries in the range of 92.0-102.2% and appropriate relative standard deviations (<= 4.47%) to analyze the biological samples to determine NSAIDs.