Some sources try to provide an approximation of true simultaneous acquisition by switching back and forth between ESI and APCI modes. After subtraction out the switching dead time, a switching source spends less than 50% of its time in each ionization mode. The inevitable result is a loss of sensitivity. This is especially serious when doing fast chromatography with narrow peaks.
The Agilent multimode source makes no such compromises. It is can acquire data in both ionization modes 100% of the time. Sensitivity in mixed (simultaneous acquisition) mode is nearly identical to the sensitivity provided by Agilent's state-of-the-art, individual ESI and APCI sources.  |