Application of response surface methodology to optimise vortex-assisted dispersive liquid-liquid microextraction combined with HPLC for determination of naproxen in Chabahar Bay

A simple, fast and efficient technique for the enrichment and determination of naproxen (NAP) in seawater and tablet samples was developed utilising vortex-assisted dispersive liquid-liquid microextraction (VADLLME) followed with high-performance liquid chromatography combined with fluorescent detection. The microextraction protocol is based on the fast injection of extracting and dispersing solvent into the aqueous solution, followed by stirring with a magnetic stirrer, to form a cloudy ternary component (water sample:extracting solvent:dispersive solvent) system. The different factors affecting extraction were investigated with one-variable-at-a-time and response surface methodology. Four independent variables, such as pH, volume of disperser, volume of the extraction solvent and amount of KCl were coded as A, B, C and D at three different levels. Linearity was achieved in the range of 1-200 mu g/L with limits of detection of 0.17 mu g/L for the analyte under the optimum conditions. Finally, the VADLLME procedure was successfully utilised for preconcentration of NAP in seawater of Chabahar Bay and tablet samples.