Columns | Column: GC Connections

A gas chromatography laboratory with equipment in operation. Generated by AI. | Image Credit: © Nim - stock.adobe.com.

In Part II of our exploration of splitless injection, we will see that it is a surprisingly complex process, and that it is difficult to understand because we cannot see what is happening during the injection process. For this discussion, we will think of the injection process as beginning with the syringe plunger being depressed and ending with the start of a temperature program in the column oven. In most splitless injections, this process requires 30 s to 1 min. There are several band broadening and focusing mechanisms that affect the peak shapes, widths, and heights resulting from splitless injection.

Top view of vials are arranged in the auto sampler for GC chromatography in laboratory with microscope testing background | Image Credit: © Anchalee - stock.adobe.com.

In this installment, we examine several of the common parameters that can affect automated peak integration and the resulting peak areas. We will consider how the data system detects the beginning and end of the peak, how it determines the peak maximum, how real peaks are differentiated from noise, and how signals at individual time intervals are summed to generate the peak area.