Dwell volume is a critical concept in chromatography that can significantly impact the accuracy and reproducibility of your analytical results.
What is Dwell Volume
It refers to the volume between the pump and the column and plays a crucial role in the shape of the chromatogram, particularly for gradient methods.
Trying to understand the concept of dwell volume in HPLC? I like to compare chromatography concepts to stuff from everyday life. That makes it easier to understand and remember. Here is an analogy that i like to use to explain dwell volume.
When Dwell Volume Becomes A Problem
Imagine you’ve been using a validated method for the last ten years with a specific instrument. However, when you hand it over to someone with a newer, faster, and better instrument, you may notice significant differences in the chromatogram. This is likely due to the difference in dwell volume between the two instruments.
Isocratic vs Gradient Methods
While isocratic methods may not be affected by dwell volume, gradients are more likely to be impacted. Newer instruments often have lower dwell volumes, which can cause the gradient to appear scrunched up at the beginning of the chromatogram.
This can lead to incorrect peak identification, quantification, and even misinterpretation of the results.