Technical data

108 Understanding Your Agilent ChemStation
4 Integration
Integration Events
Timed Events
You can use timed events to customize signal baseline construction when
default construction is not appropriate. These events can be useful for
summing final peak areas and for correcting short- and long-term baseline
aberrations. For further information about integration events see “Initial
Events” on page 105.
Autointegrate
The Autointegrate function provides a starting point for setting initial events.
This is particularly useful when you are implementing a new method. You start
with a default integration events table that contains no timed events; you can
then optimize the parameters proposed by the Autointegrate function for
general use.
Principles of Operation
The Autointegrate function reads the chromatogram data and calculates the
optimal values for the initial integration parameters for each signal in the
chromatogram object.
The algorithm examines 1% at the start and end of the chromatogram and
determines the noise and slope for this part. Noise is determined as 3 times
the standard deviation of the linear regression divided by the square root of
the percent number of points used in the regression. These values are used to
assign appropriate values to the height reject & slope sensitivity for the
integration. The algorithm then assigns a temporary value for the peak width,
depending on the length of the chromatogram, using 0.5% for LC and 0.3% to
Table 1 1 Height and Area Reject Values
Integration Parameter Peak 1 Peak 2 Peak 3 Peak 4 Peak 5 Peak 7
Height reject Above Above Above Below Above Above
Area reject Above Below Above Below Below Above
Peak integrated Yes No Yes No No Yes