A multicapillary inlet jet disruption electrodynamic ion funnel interface for improved sensitivity using atmospheric pressure ion sources

A new multicapillary inlet and ion funnel interface for electrospray ioniza tion-mass spectrometry has been developed and demonstrated to achieve highe r ion transmission efficiency compared to a single-capillary inlet and ion funnel interface. Even though the distance between the end of the ESI inlet capillary and the exit of the ion funnel (10 cm) is significantly longer t han that of the conventional interface (typically a few millimeters), a sig nificant part of the directed inlet gas flow persists into the first stage of pumping and results in an increased gas load to the second chamber. A je t disrupter made of a circular metal disk placed on axis in the ion funnel enhanced the dispersion of the directed gas flow from a multicapillary inle t and was also found to improve the ion transmission. The ion funnel with t he jet disrupter demonstrated a 15% improvement in ion transmission (compar ed to that without the jet disrupter) and simultaneously reduced the pumpin g speed required for the first or second stage by a factor of 2-3. Compared to the sensitivity with the standard mass spectrometer interface (an API 3 000, Sciex, Concord, ON, Canada) in MS/MS operation using an interface equi pped with the jet disrupter and ion funnel, a 5.3-10.7-fold enhancement in signal was observed for samples with concentrations of 100-500 pg/muL and 1 0.2 to 14.1-fold enhancement for concentrations of 10 to 50 pg/muL. The dec reased enhancement at higher concentrations is attributed to space charge e ffects and detector saturation.