pump program to 90/10 water/ACN to flush the column for 15 min at 1.5 mL/min c. Flush the column with 10/90 water/ACN for 5 min at 1.5 mL/min d. Change the pump program back to 50/50 water/ACN to re-equilibrate the system e. Stop the pump and shut down software “HPL1(online)” f. Remove sample vials from the auto-sampler tray g.