John, thank you for your reply. What I'm trying to do here is to increase my MRM sensitivity, by changing the resolution settings of Q1 and Q3. In Analyst software there is an "open" resolution setting available, aside the low, unit and high. Now let's say, I set Q1 to high resolution (0.5 Da FWHH) and Q3 to high resolution; then Q1 set to low(>1 Da FWHH ?- not sure) and Q3 to low, etc. until all combinations are exhausted. Then, I want to compare all these modes. For example, if the pre ion is 300 and Q1 high resolution is selected, only ions with 300 + -0.25 will pass, correct? What happens with the sensitivity (decreases?) and peak shape (becomes wider?) when both Q1 and Q3 are set to open resolution? Do I make any sense here? :)

This is what the tutorial says: "The software uses pre-defined unit, high, low, and open resolution values for quadrupole mode. For quadrupole scans, there is a balance between resolution and sensitivity. The wider the peak the more intense the peak will be. The following offsets for low and open resolution are typical, but they can be changed according to standard operating procedures. • Low resolution (voltage decrease from unit resolution): 0.03 • Open resolution (voltage decrease from unit resolution): 0.30. The value of the voltage decrease from the unit resolution field may vary from instrument to instrument, but for small molecule applications this value should be set to 0.03 for low and 0.3 for open. The software has four resolution parameters for the quadrupoles: unit, high, low, and open. The peak widths are set at 0.7 (±0.1 Da FWHH) for unit and 0.5 (±0.1) for high resolution. This is done by adjusting the resolution offsets. The software calculates the low and open resolution parameters from the unit resolution parameter."