The effect of ruthenium(III) chloride on the formation of protonated parent ions in electrospray mass spectrometry

We report the use of RuCl3 as an alkali metal sponge. This is a general and highly efficient method for generating protonated parent ions for a variety of compounds that usually do not show this ion in electrospray mass spectrometry. This technique is demonstrated to be highly useful in "cleaning up " spectra from multiply metallated ions, thereby substantially improving the signal-to-noise ratio