Setting the STORI Straight: Improved Signal Processing for Charge Detection Mass Spectrometry

Charge detection mass spectrometry depends on the accurate measurement of both the m/z and charge of individual ions. While the selective temporal overview of resonant ions (STORI) approach is a powerful tool for determining ion charges, its original implementation lacked the ability to account for errors or shifts in an ion’s frequency during measurement. The misSTORI algorithm was developed as an extension of STORI, providing significant improvements to charge determination in a variety of scenarios. The algorithm of misSTORI is presented here in more detail, demonstrating how small chunks of the frequency domain around a signal of interest can be utilized to extract a given ion’s charge and any relevant information about its appearance, disappearance or mass shifting during its acquisition. Various examples are provided which demonstrate the power of misSTORI in both improving the accuracy of charge measurements and revealing interesting properties of ion behavior inside the mass spectrometer.