high resolution mass determination

[jiang295]

should I isolate compound or just use lc column. which one will give me more accurate mass. thanks.

[Don_Hilton]

I would expect the accuracy of the mass to depend on the instrument used, the mass calibration, the stability of a reference mass signal and the signal strength for your unknown. What are the differences between running the compound on the LC and isolating the compound?

[jiang295]

I know that my question probably is silly but I just want to know what is the "general rule" to do HRMS. but it seems there is no such a general rule.
as i understand, pure analyte with pump syring could well control signal strength and less interference, which will guarantee more mass accuracy. but it is also very time consuming.

I would expect the accuracy of the mass to depend on the instrument used, the mass calibration, the stability of a reference mass signal and the signal strength for your unknown. What are the differences between running the compound on the LC and isolating the compound?