In figure 5b, [M+Na-H2O]+ ion peak at m/z 475 was observed. The peak is hidden by back ground. How do you define the limit of detection?
(1) From the reviewer's point, you should explain why the Low response in the Mass Spectrum?(2) Optimize the Mass Spectrum of product ion: adjust the CID little by little, do not need to change the energy of cone voltage. low down the gas flow rate of CID, wait 10 min until equilibrium, increase the collision energy at Q2.
(3) If the Professor only care the Low response in the Mass Spectrum, here I have one "non-professional" shortcut: Inject twice in one time ( do not use the syringe pump), one could use low CID, other use high CID for about 2-5 min. Then use the second one as background to extract the First one. you definitely get high abundance on your mass spectrum. ( actually they are the same, but you could hide the response value in the Y axis, only put the abundance.)
Do not abuse the tip a lots, some reviewer hates that so much.
Good Luck...
