1200 Series DAD and MWD User Manual 85
How to optimize the Detector 5
In a four-component mixture, only biphenyl was recorded. The other three
peaks were suppressed because they did not meet the ratio-qualifier criterion
and therefore the output was set to zero. The characteristic wavelengths
249 nm (λ
1
) and 224 nm (λ
2
) were found from the spectra shown in Figure 35.
Figure 35 Wavelength Selection for Ratio Qualifiers
Figure 36 Selectivity by Ratio Qualifiers
Select 2 characteristic
wavelengths
Signal = WL1/WL2 20%
o-Terphenyl
Biphenyl
Wavelength (nm)
WL1
WL2
Scaled
Signals at 250 nm
No selectivity
With ratio qualifier
250/222 nm = 3.5 20%
Biphenyl
o-Terphenyl
Time (min)