The principles of compound separation are illustrated in these figures. In figure (a), the mixture of compounds is introduced to the column. This is typically accomplished by injecting the sample mixture through a septum with a syringe. Figure (b) illustrates how a compound (represented by triangles) resides on the stationary phase while another compound (represented by circles) resides in the mobile phase (carrier gas) and is swept through the column at a faster rate. Figure (c) illustrates continuing separation of the two analytes. Figure (d) illustrates total separation, also referred to as complete resolution, of the two compounds. As the compounds elute from the column and are analyzed by the detector, a chromatogram with two completely resolved peaks will be generated.