Molecular weight determination of proteins from multiply charged ions using thermospray ionization mass spectrometry

Abstract

AbstractData are presented showing the use of thermospray ionization to generate multiply charged ions for a number of proteins over the molecular weight range 5000–30000. These measurements were carried out on an unmodified, commercially available thermospray ion source. Between +3 and +19 charges were observed for a series of model proteins. Data can be obtained on as little as 100 pmol of sample. The accuracy and precision of the molecular weight determinations for these proteins is similar to those previously reported for these samples using electrospray or ionspray ionization. The formation of multiply charged ions from proteins via thermospray ionization occurs over a wide range of aqueous/organic solvent compositions, facilitating its interfacing with high‐performance liquid chromatography using conventional diameter columns.