Agilent Technologies 1220 Infinity II LC User Manual page 132

8
Detector Description
Agilent 1220 Infinity II LC Diode Array Detector (DAD)
Figure 44
Ratio Qualifiers for Selective Detection of Compound Classes
Ratio qualifiers can be used where, in a complex sample, only one particular
class needs to be analyzed — a parent drug and its metabolites in a biological
sample, for example. Another example is the selective analysis of derivatives
after pre- or post-column derivatization. Specifying a signal ratio that is
typical for the sample class is one way of selectively plotting only those peaks
that are of interest. The signal output remains at zero so long as the ratio is out
of the user-specified ratio range. When the ratio falls within the range, the
signal output corresponds to the normal absorbance, giving single, clear peaks
on a flat baseline. An example is shown in
Figure 46
132
Peak Suppression Using Reference Wavelength
on page 133.
Figure 45 on page 133 and
1220 Infinity II LC System User Manual