Dear All,
I am developing a method for streptomycin in Xevo TQD LCMSMS using Hillic column.Mobile phase is 200mM Ammonium formate in water and acetonitrile.i am looking for a 1ppb detection.I am getting a hump in blank at the time of RT.When i change gradiant then also hump came at time of RT .Diluent is 2% formic Acid :ACN 80:20.Why this happens?any good method is there please share me