Читать книгу Process Gas Chromatographs - Tony Waters - Страница 50

Notice that the propane molecules do not all spend the same time in the column, even though they are identical to each other. They enter the detector at different times.

The variable arrival time of identical molecules at the detector is the root cause of chromatogram peak shape.

Clearly, some of the propane molecules are delayed longer in the liquid phase than others are. It's a crap shoot in there, a totally random process where some get left behind and others don't. As a result, the peak shape follows the standard bell‐shaped curve that is found in many random processes. You saw this happen in Figures 2.5–2.8.