Self-correlation method for processing random phase signals in Fourier Transform Mass Spectrometry

Image current measurement followed by Fourier transform has been widely used for Fourier transform ion cyclotron resonance and Orbitrap mass spectrometers. It has also been explored as a non-destructive mass analysis method using quadrupole ion traps. The phase between the ion excitation and the image current measurement typically needs to be well controlled for obtaining high quality spectra. In this study, a data processing method based on self-correlation (SC) function has been explored for signal enhancement with image current data recorded at random phases. The simple algorithm of the SC method was introduced and a series of data used for demonstrations was simulated based on a previous study on non-destructive mass analysis using an ion trap. A significant improvement has been achieved in the signal-to-noise ratio (SNR) as well as in the accuracy of the peak ratio. The efficiency of using a mask data set for selected ion monitoring has also been demonstrated.

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► A simple algorithm based on self-correlation function has been developed for signal enhancement with data recorded at random phases during the image current measurements.
► The effectiveness of the method has been demonstrated with data of low signal-to-noise ratios (as poor as −40 dB).
► Various ways of implementing the SC method have been developed and demonstrated.