Salting-out liquid–liquid microextraction to the determination of mycophenolic acid in plasma samples

This study aimed to develop a determination method of mycophenolic acid (MPA) in biological samples using salting-out liquid–liquid microextraction from human plasma samples based on the formation of a fluorescent complex with terbium ion and its application in quantification of the MPA in clinical samples. MPA extracted from plasma samples by salting-out liquid–liquid microextraction after protein precipitation by acetonitrile. Then, the fluorescence intensity was measured at 545 nm using an excitation wavelength of 347 nm after optimization of extraction parameters. Under the optimum conditions for the developed method, it provided a linear range between 0.5 and 5.0 µg/mL with a correlation coefficient (R2) of 0.998, and then, the validation was performed according to the FDA guideline and the developed method could quantify MPA concentration in real plasma samples. The results showed that linearity, accuracy, and precision of the developed analysis method were suitable for the determination of the MPA in plasma samples.