Hi,

I have question about calculation of resolution in Qual MassHunter B.07.00. I tried calculate mannualy value of resolution, next I compared it with value calculated by MassHunter but results were not comparable.

Could someone help me with this? Any idea what is the problem? What is the acceptable limit for resolution?

I will be very grateful for help.

Please see below calculation.

In mannualy calculation I used two above formulas (1) & (2).

Formula 1 (used for Pharmacopoeia USP)

** ****R** = (8.055 - 7.952)/0.5*(0.09 + 0.135) = **0.92**

MassHunter Qual **R = 1**

Formula 2 (used for Pharmacopoeia BP)

**R** = 1.18*[(8.055 – 7.953)/(0.039 + 0.041)] = **1.50**

MassHunter Qual **R = 2.2**

Kind regards,

Ewa

I added tags to this post to increase visibility.

I believe the difference in your calculated resolutions and the resolution values that are being reported in the peak table is due to the peak width values you are using in your calculations. If you take a look in the MassHunter Help contents it defines what peak width values are used for the different pharmacopoeia calculations:

For USP, Qual is going to be determining the peak width using the tangent method. This does not correspond with either the Width or the FWHM values that you see in your peak table. The Width values you are using are actually the Full Peak Width values and not the tangent peak width (illustrated as WB in the below figure):

Unfortunately, the tangent peak width is not stored as a variable in Qual so there is no way to display it in the software.