Can someone please explain the basic differences in these two? A little detail please?

Thanks a lot

Sean

Sean,
In headspace GC, you're extracting volatile components out of your sample matrix and transferring it to your GC. Onnly those volatile components will enter your GC, unlike with "regular" GC. In "regular" GC, you're usually injecting a sample solution into your inlet and flash vaporizing your sample. In this case, volatile components will travel through the column to your detector. Those compounds that are not so volatile will most likely be deposited on your liner or the front end of the column.