Empower Tip: Review Window and the Processing Method

Question: How do I calculate column void volume?

One way to determine the void volume time is to inject something that will not be retained on the column and use the retention time of the unretained component. There is a way to do this mathematically and have Empower do this for us.

STEP 1 The math is illustrated in ‘Help’ in the Columns Calculator v2.0..

Create Custom Sample Fields for Column Length, Column Diameter, and Porosity Factor. In this case, we use a column with a length of 15cm and an internal diameter of 0.46cm with a porosity factor of 0.66.

Create a Custom Result Field to calculate Column Volume.

Create a Custom Result Field to calculate Void Volume.

Empower calculates the Void Volume in ml and the value can be entered in to the Processing Method on the Suitability tab.

Now we have accurate calculations for K Prime and Selectivity.

It’s that easy!