Microextraction of Furosemide from Human Serum and Its Fluorimetric Determination

Background: A new, fast and sensitive spectrofluorimetric method was proposed for the determination of furosemide in serum samples based on a dispersive liquid-liquid microextraction. Methods: The optimum conditions for quantification of furosemide were studied considering the effects of types and amounts of dispersive and extraction solvents, salt addition, pH value, rate and duration of centrifugation. The method was validated with respect to the linearity, recovery and limit of detection. Results: Under the optimal conditions, the fluorescence intensities at 406 nm (with the excitation wavelength of 342 nm) were linear with the concentration of furosemide in the range of 0.3 to 20 μg mL^-1, with a detection limit of 0.12 μg mL^-1 and a relative standard deviation of 3.4–9.4%. Conclusion: Careful examination of the obtained validation results reveal that the proposed method is suitable for determination of furosemide in serum samples.