Development of an in-syringe gas-assisted density tunable solidification of floating organic droplet-based dispersive liquid phase microextraction method coupled with HPLC-MS/MS for monitoring amikacin in biological fluids.

A new sample preparation method named in-syringe gas-assisted density tunable dispersive liquid phase microextraction based on solidification of floating organic droplet has been introduced. This method was coupled with high-performance liquid chromatography-tandem mass spectrometry and used for the extraction and quantification of amikacin in plasma and exhaled breath condensate (EBC) samples of the patients receiving amikacin. In the proposed approach, an inert gas is bubbled into a syringe barrel containing aqueous solution of the analyte and a mixture of low density extraction solvent and volatile density modifier. Consequently, the density modifier is evaporated and the analyte is migrated into the released extractant droplets. Basic parameters affecting efficiency of the developed method were optimized. Under optimum conditions, the method limits of detection were 0.06 and 0.29 ng/mL in EBC and plasma, respectively. The extraction recoveries were 90% and 87% in EBC and plasma, respectively. Also, the obtained relative standard deviations were below 9.5% and 9.8% for EBC and plasma, respectively. Considering these results, the developed method provides a quick and efficient way to determine amikacin in patients' biological fluids and can be used widely in drug monitoring and clinical studies.