Canadian chemists have used ionic liquids to broaden the range of compounds that can be studied with mass spectrometry.

Scott McIndoe of University of Victoria, Canada, used the analytical technique electrospray ionisation mass spectrometry (ESI-MS) to provide structural information on samples in non-polar solvents. Until now, only polar solvents could be used for recording ESI-MS spectra, which restricted the potential for this widely used technique.

'There are numerous examples of compounds that are attractive targets for ESI-MS analysis, but which decompose in polar solvents,' said McIndoe. 'We sought a solution to this problem by taking advantage of the ready availability of ionic liquids.' McIndoe said that they tackled the lack of conductivity in non-polar solvents by adding an ionic liquid electrolyte to a range of non-polar solvents.

This development is welcomed by Michael Gross of Washington University, US. 'The use of ionic liquids in electrospray ionization is a clever idea that is thoughtfully motivated. There are early indications of broad applicability to many non-polar analytes that up until now haven't worked well by electrospray ionization,' he said.

Rebecca Gillan