Response surface methodology for optimization and determination of Riluzole by microfunnel magnetic stirring-assisted liquid–liquid microextraction coupled with high-performance liquid chromatography

A rapid, simple, and highly sensitive microfunnel magnetic stirring-assisted liquid–liquid microextraction coupled with HPLC was developed for determination of Riluzole (RLZ). The main extraction parameters were screened using the Plackett–Burman design and optimized by central composite design. Under optimum conditions, the calibration curve was linear over the range of 0.2–400 ng mL−1, and RSD of 3.21% (n = 14, 20 ng mL−1) proved to have good reproducibility. The detection limit was 0.023 ng mL−1 and 1.5 ng mL−1 for aqueous and biological samples, respectively. The tap water, human plasma, and urine samples showed excellent recoveries for RLZ (97.09–101.92%) via this method.