Hello, I am trying to perform MS1 scan of Dimetridazole (positive ESI mode), which is solved in MeOH, in mass range of 50-200amu. I am getting inverse/negative peaks. Besides, whenever I try an MRM transition 142>96(based on literature), I don't get a peak whatsoever. I have tried capillary voltages of 5, 3, 3.5 kV but nothing has increased my signal intensity significantly. What possibly can lay behind all of this? Should I try cleaning the ion source? I use water and MeOH as mobile phases. I would really appreciate your opinions!

Thank you!