Magnetic deep eutectic solvent-based microextraction for determination of organophosphorus flame retardants in aqueous samples: One step closer to green chemistry

A ferrofluidic hydrophobic deep eutectic solvent-based on dispersive liquid–liquid microextraction combined with gas chromatography-flame ionization detection was developed for preconcentration, separation, and quantification of organophosphorus flame retardants in aqueous samples. The magnetic deep eutectic solvent was prepared by sonicating silica-coated magnetic particles and benzyltriphenylphosphonium bromide-1-undecanol as the carrier liquid. A multivariate strategy containing central composition design and a univariate methodology were employed for optimization of the independent variables effective in the efficiency of sorption and desorption steps, respectively. Method validation study performed under optimal conditions, demonstrates the proper linear range for the analytes calibration curves with the limit of detection the range of 3.0 to 23.0 ng/L and the limit of detection lower than 50.0 ng/L. Intra- and inter-day precision measured at three concentrations for the goal analytes were lower than 5.9 and 8.5 %, respectively. The method intra-day accuracy (96.8–102.0 %) and inter-day accuracy (96.5–103.1 %) illustrate the satisfactory applicability of the proposed method for the analysis of the goal analytes in aqueous samples.