Model independent peak fitting and uncertainty assignment for high-precision time-of-flight mass spectrometry.

A procedure is introduced to extract the time-of-flight probability density distribution for ions of one type using an accumulated ion peak as a template for use in the fitting of time-of-flight peaks of co-accumulated ions. We demonstrate the use of logarithmic splines and discuss the statistical criteria for the selection of the spline smoothing parameter to obtain a smooth function for approximating such an ion peak. Furthermore, a "Bootstrap" method is proposed to determine the uncertainty of the fitted time-of-flight values, which is calculated using the extracted peak shape via a repeated statistical experiment.