Evaluation of sample preparation and chromatographic separation for the parallel determination of taurine and edaravone in rat tissues using HILIC-MS/MS.

The quantitative analysis of taurine and edaravone in biological sample is critical in pharmaceutical studies. Although each of them can be individually analyzed by different approaches, concurrent quantification is still a highly challenging task with respect to their great polarity variation and the complex composition of tissue sample. In the present study, to simultaneously determine taurine and edaravone in rat tissue, the sample preparation and chromatographic separation conditions were evaluated and discussed in detail. As for the sample preparation, four kinds of solvent and the volume ratio of the optimal solvent to biological sample were both tested and evaluated based on the chromatographic profile, extraction recovery, and matrix effect (ME). The chromatographic separation was performed in a reverse phase (RP) and two hydrophilic interaction liquid chromatography (HILIC) modes, and the corresponding separation efficiencies were assessed using chromatographic parameters like half-width (W 1/2 ), tailing factor (f t), theoretical plates number (N), and ME. Furthermore, adopted composition of two mobile phase systems and the concentrations of the additives in the optimum buffer system were also investigated on an Atlantis HILIC silica column according to the resultant chromatographic profiles and peak areas of the analytes. The optimal results were obtained when the biological samples were deproteined by 4-fold volume of methanol/acetonitrile (1:3, v/v) and separated on a HILIC column with a gradient elution of acetonitrile/water containing 0.2 % formic acid and 10 mM ammonium formate. The proposed approach was validated and successfully applied to the parallel determination of the tissue distribution of edaravone and taurine in rat tissues.