Abstract
The variation of the standard deviation of the molecular weights determined by electrospray with the average charge number of multiply charged ions is investigated for peptides and proteins with molecular weights ranging from 1000 to 20000. This result shows the tendency that the standard deviation of experimentally determined molecular weights increases with the average charge number of multiply charged ions. It is found that the molecular weight determination by electrospray accompanies the error of at least the product of 0.06 and the average charge number in the experiment.
