Abstract
A simple and precise reversed-phase high-performance liquid chromatography method for the separation and trace determination of selected non-steroidal anti-inflammatory drugs (ketoprofen, naproxen, sodium diclofenac, and ibuprofen) was developed. The proposed method was based on the use of high temperatures with a C18 column and a low volume of acetonitrile as the mobile phase, and the analysis time is less than 8.0 min. The van't Hoff plots for the tested drugs were linear, suggesting no significant changes in the retention mechanism. The limits of detection for ketoprofen, naproxen, sodium diclofenac, and ibuprofen were found to be 0.00012, 0.00008, 0.00162, and 0.00127 µg L
−1
, respectively, and their limits of quantification were 0.0004, 0.00025, 0.00541, and 0.00424 µg L
−1
, respectively. Intraday analysis was performed yielding relative standard deviations (RSD) of less than ±1.5%, whereas the interday RSD was 1.01%. The proposed system was applied for the separation and determination of the drugs in water, urine, and pharmaceutical samples, and acceptable recoveries from 97.20% to 99.6% were obtained.