Column integrity test
The column integrity test must be performed before first use and is the recommended test when column damage is suspected. Column integrity is evaluated with a pulse-response test, which measures the detector response (UV, conductivity) of a non-binding tracer. The tracer is injected into the flow path of the system and eluted by an isocratic elution with a suitable mobile phase. The duration from tracer injection to elution is the retention time of the tracer and should conform to a defined criterion. To account for dead volume of the system, it is necessary to first perform a tracer injection without connecting the column. A pulse response test is therefore performed on the LC system without the column and with the column connected to the system. The peak shape and the retention time of the tracer give an indication of column integrity.