schordinger
In mass spectrometer, the resolution required was defined as
M/(delta M), So, it means for two larger M.W. molecules, the resolution required was larger than small M.W. molecules even the delta M was was the same.....

But why ??!!
why the instrument should have better resolution to distinguish different larger molecules ??!!

Thx...[?]

Chemicalsuperfreak
Don't know much about mass spectroscopy.

But if I had to guess...

For small molecules, the empirical formula can be calculated from the MW. There's only one formula possible for the MW 130.1418, for example. Even mass spectrometers with low resolution can figure it out for small molecules. WIth large, particularly biological molecules there are more combinations and permutations that can give very similar MW's. So having a high resolution probably helps here. But I'm not sure. I don't handle many compounds more then several hundred daltons.

schordinger