Page 110 - Illustrated Pocket Dictionary of Chromatography

INTEGRATION 107

tions from the injector to the column and on to the detector, small-ID
stainless steel is used, often in the range of 0.005in. This minimizes
extra-column volume and the peak broadening associated with it. For
injectors, the volume contained is crucial and so the appropriate ID
must be used in order for the proper volume to be contained for injec-
tion (see table).

integration The process of determining the area under a peak.
Integration is composed of two distinct events: Integration is started
and then terminated. These events are often linked to the change
detector signal (i.e., the slope). This becomes very difficult when

The top profile shows a good integration where the entire peak is included and the
integration points (i.e., the vertical lines) are near the start and end of the peak. In
the bottom left example, there is a rising baseline to the peak. The integration trig-
gers too early, giving an area that is larger than the true peak area. In the bottom
right example, the triggers occur too late and not all of the peak is integrated,
leading to an underestimated peak area.