Question about resolution.

[victorio008]

Hi all,

Can somebody explain me what means resolution 1amu in mass spectrometry.
I ask because I want to compare two different mass systems. First has 1 amu resolution, the second has 2M (FWHM). Which is better?
Sorry for my bad english.

Thank you in advance!

[Jetjamnong]

Mass Spectrometry have 2 definition about mass resolution. First with 10% valley and second with FWHM (Full Width at Haft Maximum). For 1 amu resolution (10% valley) is measured between 2 ion normally structural ion (A) and it isotope (A+1).
For example,
Resolving power with 10% valley (Measured at 10% Intensity) = M1/M2-M1
Resolving power measured with FWHM (Measured at 50% Intensity) = M1/peak width

Which is better?
Instrument 1; M1 = 234.567, peak width (FWHM) = 0.1 amu.
Resolving power/Resolution = 234.567/0.1 = 2346

Instrument 2 ; M1 = 234.567, peak width = 0.07 amu.
Resolving power/Resolution = 234.567/0.07 = 3351

m/z resolution 3351 is better than 2346.

Is this help?

[victorio008]

Thank you