The amenability of different solvents to electrospray ionization mass spectrometry

Electrospray ionization mass spectrometry is capable of transferring ions from solution to the gas phase across a broad range of solvents. A systematic investigation of the relative performance of different solvents has not been previously conducted, and we sought to remedy this situation. Fourteen solvents across a wide range of polarities were investigated for their ability to provide strong signals for four permanently charged ions. We found the best solvents to be acetone, acetonitrile, dichloromethane, tetrahydrofuran, and the previously unused (in an ESI-MS context) trifluorotoluene.