A new microextraction approach termed forced vortex assisted liquid phase microextraction (FVA-LPME) has been developed and optimized for spectrophotometric determination of mefenamic acid (MFA) as a model compound. FVA-LPME is based on the formation of a rotational vortex of organic phase within aqueous phase and subsequent partition of target analyte between two phases. Rotation of fine layer of organic phase as a solid body within aqueous phase accelerates the mass transfer and improves the extraction efficiency. MFA is extracted into organic phase by FVA-LPME procedure and subsequently derivaitized by iodine to form a charge transfer complex for spectrophotometric detection. A response surface methodology (RSM) based on central composite chemometrics design was used for multivariate optimization of the effects of three different parameters influencing the extraction efficiency. Under the optimal conditions, the calibration curve was linear in the range of 10–900 ng mL-1 of MFA with a R2 of 0.998. The repeatability and reproducibility (RSD%) for 200 ng mL-1 MFA were 2.6% and 3.3%, respectively and limit of detection limit (S/N = 3) was estimated to be 3.1 ng mL-1. The results demonstrated that the developed method is an accurate, inexpensive, rapid and reliable sample pretreatment method that gives very good enrichment factor and detection limit for extracting and determining MFA in biological samples.
