3 mL of each solvent phase was added to the vials containing compounds. The samples were vortexed for 30 minutes and then allowed to settle for 60 minutes. Once the solutions reached equilibrium, they were checked for any particulate in both the top and bottom phases to ensure that the drug was in solution. If particulate was still observed in the phases, the vials would be vortexed for an additional 30 minutes, then allowed to reach equilibrium. 500 µL of solution was drawn from the upper and lower phases of the 8 mL vials (Figure ) by way of a 22 gauge syringe needle attached to the Unchained Labs CM3 platform. This narrow-gauge needle is beneficial to reducing potential error due to the low surface area of the exposed needle, the positive air gap inside the needle capillary, and the presence of a septum on the vial cap which wipes away any errant solvent when the needle is withdrawn from the vial. The aliquots of solution were then individually transferred into separate 1 mL vials on the 96-well plate for HPLC analysis using the Agilent 1290 auto-sampler. The sampling height was optimized so that the needle withdraws the liquid at the mid-height position for each of the phases to avoid cross contamination due to liquid eddies that may potentially form due to the sampling needle creating turbulence at the solution interface. This ensured consistent and reproducible sampling conditions for every sample analyzed. The aqueous phase used in the above experiments involved the use of Britton-Robinson buffers.