Waters 2475, Operator'S Manual, Page: 33 / 228

Auto-optimize gain 1-19
setting for all peaks in the chromatogram and no segregated peak region
optimization.
Example of recommended method development approach
A method with two timed event changes optimizes the chromatogram shown
below.
Gain optimized chromatogram
The first gain setting change occurs at 1.5 minutes, just before the small peak
that is best detected at a gain of 1000. The next change, at 2.0 minutes, is the
required wavelength-pair change. Initial gain setting or conditions are not
critical. The only requirement for the first timed event is that some gain
setting takes place. An initial method table is shown below.
Example of method development
Time (min) Event
Initial (0.0) Excitation = 375 nm, Emission = 410 nm, Gain = 100
1.5 Gain = 1
Emission
Time
Region 1 Region 2 Region 3
Gain: 10
Ex: 375 nm
Em: 410 nm Gain: 1000
Ex: 375 nm
Em: 410 nm Gain: 5
Ex: 395 nm
Em: 440 nm