Acquity uplc ms sqd system

The aqueous kinetic solubility was determined from a 10 mM DMSO stock solution of test compound in Phosphate Buffered Saline (PBS) at pH 7.4. The study was performed by incubation of an aliquot of 10 mM DMSO stock solution in PBS (pH 7.4) at a target concentration of 250 µM resulting in a final concentration of 2.5% DMSO. The incubation was carried out under shaking at 25 °C for 24 h followed by centrifugation at 21.100 g for 30 min. The supernatant was analyzed by UPLC/MS for the quantification of dissolved compound by UV at a specific wavelength (215 nm). The analyses were performed on a Waters ACQUITY UPLC/MS SQD system consisting of a SQD (Single Quadrupole Detector) Mass Spectrometer equipped with Electrospray Ionization interface. The analyses were run on an ACQUITY UPLC BEH C18 column (50 × 2.1mmID, particle size 1.7 µm) with a VanGuard BEH C18 pre-column (5 × 2.1mmID, particle size 1.7 µm), using 10 mM NH₄OAc in H₂O at pH 5 adjusted with AcOH (A) and 10 mM NH₄OAc in CH₃CN-H₂O (95:5) at pH 5 (B) as mobile phase.