Chemometrics optimization of an anionic carrier-mediated hollow fiber liquid-phase microextraction combined with HPLC-PAD for fluconazole extraction from plasma samples

Abstract

In this research, we developed a method for fluconazole (FLU) quantification in plasma using carrier-mediated hollow fiber liquid-phase microextraction (HF-LPME). Briefly, the investigation of six solvents for fiber impregnation, two and three-phases modes of HF-LPME, and carrier-mediated HF-LPME were performed. A fractional factorial design 2(8–4) showed the influence of eight factors and it was followed by a central composite design with the most important three factors. Response surface and desirability test were also obtained. After optimization, the extraction condition consisted of the use of 500 µL of plasma samples containing FLU and 4.5 mL of NaOH solution (0.316 M) saturated with Na2SO4. Centrifugation was required for 15 min at 2200 g and 4 °C for sediment removal. A volume of 3.5 mL was transferred to extraction tubes and the fibers, already impregnated with 1-octanol and Adogen 464 (10 %), were placed in contact with the sample. Then, 60 µL of the acceptor phase were added inside the fiber, and stirring was performed at 1000 rpm for 40 min. Validation was performed in consonance with European Agency's Guideline on Bioanalytical Validation Methodology. The method showed linear range from 1.0 to 62.5 μg mL−1, recovery of 12 %, selectivity, no carryover effect, precision and accuracy within the recommended limits, and samples were stable in the stability studies performed. Finally, we confirmed the applicability of the obtained method at two samples obtained from a patient treated for neuromycosis with FLU. It is the first time that a microextraction technique is used for FLU analyses in plasma samples. The method showed good perspective of application in drug monitoring, without the need of large amounts of organic solvents that can be very harmful to health and environment.