Collision-induced signal enhancement (CISE): The use of boundary activation to effect non-resonant CISE

An alternative to resonant excitation collision-induced signal enhancement (CISE) is presented. This alternative utilizes boundary activation instead of resonant excitation to effect CISE and is called boundary activated collision induced signal enhancement (BA-CISE). There are three ways to effect BA-CISE to enhance the signal for an MSn+1 experiment. Each technique utilizes the beta(z) = 0 boundary, which ions encounter from high to low mass/charge ratio. BA-CISE is shown to produce an almost 900% increase in the C-2 ion of [maltohexaose + Li](+). The use of a heavy collision gas in addition to the helium bath gas generally produced a signal enhancement inferior to the same experiment without the heavy gas. (J Am Soc Mass Spectrom 2002, 13, 650-658) (C) 2002 American Society for Mass Spectrometry.