Blank Peaks

[Sunjay]

Dear All,

We are doing stability studies of developmental drug products.

Sometimes, we get some peaks appearing in blank having some area (say 1000). We get the peak at same RT in test but the area is high (say 2000).

Same thing happen with placebo and test solutions also.

In such cases what should be done? Shall we neglect the peak in test as blank peak?

Regards

[DR]

If it is reproducible and in your blank, one approach would be to label it a system peak and disregard it in your calculations.

A better approach would be to find the source of the peak. If you're running a gradient and it appears near the end of the gradient, there is a simple test to tell you if it's A-phase related. Setup for back to back blank injections. Let the system run under its initial conditions for ~20 minutes before starting the blank injections. If the system peak is significantly larger in the first of the injections, you may well have some water (A phase) issues. Search these forums for my posts containing the word "Empore" for the fix (Empore extraction disks).