Column Switching Techniques

The use of column switching techniques is not exclusive to capillary column systems, but the procedures lend themselves more readily to open tubular columns than packed columns, and, consequently, are extensively employed for certain types of analyses. Switching procedures are particularly useful in 'back flushing' techniques and in 'heart cutting' specific samples from a partially resolved mixture.

Figure 20. Sample Injection in the Back Flushing Procedure