George S. Moore

Accelerated Time-of-Flight Mass Spectrometry

We study a simple modification to the conventional time-of-flight mass spectrometry (TOFMS) where a variable and (pseudo)-random pulsing rate is used, which allows for traces from different pulses to overlap. This modification requires little alteration to the currently employed hardware. However, it requires a reconstruction method to recover the spectrum from highly aliased traces. We propose and demonstrate an efficient algorithm that can process massive TOFMS data using computational resources that can be considered modest by todays standards. This approach can be used to improve duty cycle, speed, and mass resolving power of TOFMS at the same time. We demonstrate the efficacy of our method by running an experiment using a conventional TOFMS instrument and simulating the output of the modified scheme using these observations. Our result shows that the new scheme can result in a ten fold speed up of the instrument. We expect this to extend the applicability of TOFMS to new domains. Moreover, we detailed how our work represents an example in the statistically sparse signal acquisition paradigm. In this regime, a (possibly dense) signal x can be observed only through noisy sparse measurements where all but a small, random, unknown fraction of the entries are set to zero in each observation. We argue that improving the acquisition efficiency through random linear measurements in this regime has many possible applications and represents a host of both practical and theoretical challenges.

Dithered multi-pulsing and non-parametric statistical inference algorithm for time-of-flight mass spectrometry

Time-of-flight mass spectrometers have classically been limited in the maximum ion pulser firing rate by the flight time of the slowest analyte ion present. This paper describes a new randomly dithered ion pulser firing scheme that operates in conjunction with a non- parametric iterated statistical inference algorithm, inspired by the Belief Propagation algorithm, to resolve the multiple time-of-flight aliases that result for firing rates above this classical limit. This algorithm readily exploits available a priori information and several acceleration techniques are applicable. Simulations of this method with a 10x firing rate increases show excellent fidelity with classically measured spectrums.

Accelerated time-of-flight mass spectrometry

We employ a simple modification to the conventional time of flight mass spectrometry (TOFMS)where a variable and (pseudo)-random pulsing rate is used which allows for traces from different pulses to overlap. This modification requires little alteration to the currently employed hardware. However, it requires a reconstruction method to recover the spectrum from highly aliased traces. We propose and demonstrate an efficient algorithm that can process massive TOFMS data using computational resources that can be considered modest with todays standards. Our approach can be used to improve duty cycle, throughput, and mass resolution of TOFMS at the same time. We expect this to extend the applicability of TOFMS to new domains.