Optimizing Splitless Injections in Gas Chromatography, Part II: Band Broadening and Focusing Mechanisms

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.