No abstract

This study investigates to which extent the design of electrospray ion sources influences the susceptibility to matrix effects (MEs) in liquid chromatography–tandem mass spectrometry (LC–MS/MS). For this purpose, MEs were measured under comparable conditions (identical sample extracts, identical LC column, same chromatographic method and always positive ion mode) on four LC–MS/MS instrument platforms. The instruments were combined with five electrospray ion sources, viz. Turbo Ion Spray, Turbo VTM Source, Standard ESI, Jet Stream ESI and Standard Z‐Spray Source. The comparison of MEs could be made at all retention times because the method of permanent postcolumn infusion was applied. The MEs ascertained for 45 pesticides showed for each electrospray ion source the same pattern, i.e. the same number of characteristic signal suppressions at equivalent retention times in the chromatogram. The Turbo Ion Spray (off‐axis geometry), Turbo VTM Source (orthogonal geometry) and the Standard Z‐Spray Source (double orthogonal geometry) did not differ much in their susceptibility to MEs. The Jet Stream ESI (orthogonal geometry) reaches a higher sensitivity by an additional heated sheath gas, but suffers at the same time from significantly stronger signal suppressions than the comparable Standard ESI (orthogonal geometry) without sheath gas. No relation between source geometry and extent of signal suppression was found in this study. Copyright © 2012 John Wiley & Sons, Ltd.

No abstract

More than 20 years and a Nobel prize since its introduction there is still a lot to learn about the mechanism ofelectrospray ionization. For example, certain compounds when present in solution can enhance or suppress ionization of a targeted species. In this month's Special Feature Stahnke and co‐workers examine whether or not ion source geometry infl uences whether or not sample matrix impacts the measured ion signal of targeted compounds.