Agilent Technologies InfinityLab LC Series User Manual page 106

5
Optimizing the Detector
Method Development
Previously, only diode array detectors and mass spectrometric detectors could
deliver spectral information on-line to confirm peak identity as assigned by
retention time.
Now, fluorescence detectors provide an additional tool for automated peak
confirmation and purity control. No additional run is necessary after the
quantitative analysis.
During method development, fluorescence excitation and emission spectra are
collected from reference standards and entered into a library-at the choice of
the method developer. All spectral data from unknown samples can then be
compared automatically with library data.
this principle using a PNA analysis. The match factor given in the report for
each peak indicates the degree of similarity between the reference spectrum
and the spectra from a peak. A match factor of 1,000 means identical spectra.
In addition, the purity of a peak can be investigated by comparing spectra
obtained within a single peak. When a peak is calculated to be within the
user-defined purity limits, the purity factor is the mean purity value of all
spectra that are within the purity limits.
The reliability of the purity and the match factor depends on the quality of
spectra recorded. Because of the lower number of data points available with
the fluorescence detector in general, the match factors and purity data
obtained show stronger deviations compared to data from the diode array
detector, even if the compounds are identical.
Table 13
emission spectra from a PNA reference sample.
106
on page 107 shows an automated library search based on the
Agilent InfinityLab LC Series 1260 Infinity II FLD User Manual
Table 13 on page 107 illustrates