Estimation of ion cyclotron resonance parameters in fourier transform mass spectrometry

A method of accurately estimating the mass of an ion comprising:

• estimating the Fourier Transform mass spectrometer parameters consisting of initial magnitude, frequency, initial phase, and decay constant from the transient voltage signal obtained by mass spectroscopy;
• and
• converting the estimated parameters into a mass-to-charge ratio by mass calibration,
• wherein the mass spectrometer is ion cyclotron resonance mass spectrometer or a machine that measures the frequency of oscillation induced by a potential that varies harmonically in one direction.

A method for identifying human cryptic peptides from mass spectroscopy data comprising

• estimating ion cyclotron parameters,
• calibrating mass using the Fourier Transform mass spectrometer parameters,
• determining exact mass based upon the calibration and determining chemical formulae based upon the mass, and
• interpreting the chemical formulae based upon a comparison of the chemical formulae obtained with data from the human proteome,
• wherein the mass spectrometer is ion cyclotron resonance mass spectrometer or a machine that measures the frequency of oscillation induced by a potential that varies harmonically in one direction.

A computer readable medium having computer executable components for estimating Fourier Transform mass spectrometry parameters comprising

• obtaining a voltage signal produced by one or more ions in a mass spectrometer wherein the measured component of the ion trajectory is a sinusoid with fixed frequency and exponentially decaying amplitude characterized by a decay time constant, and the voltage is proportional to the measured component of the ion position plus additive white Gaussian noise;
• and
• finding the point where the partial derivatives of the data likelihood of the parameters consisting of initial magnitude, frequency, initial phase, and decay constant are all equal to zero from the voltage signal by using an iterative algorithm;
• wherein the parameter values obtained maximize the data likelihood,
• wherein the mass spectrometer is ion cyclotron resonance mass spectrometer or a machine that measures the frequency of oscillation induced by a potential that varies harmonically in one direction.

A FTMS machine comprising computer readable media having computer executable instructions for estimating Fourier Transform mass spectrometry parameters wherein the computer readable medium having computer executable instructions for estimating Fourier Transform mass spectrometry parameters on the FTMS machine comprises

• obtaining a voltage signal produced by one or more ions in a mass spectrometer wherein the detected spatial component of the ion trajectory is a sinusoid with fixed frequency and exponentially decaying amplitude characterized by a decay time constant, and the voltage is proportional to the measured component of the ion position plus additive white Gaussian noise;
• and
• finding the point where the partial derivatives of the data likelihood of the parameters consisting of initial magnitude, frequency, initial phase, and decay constant are all equal to zero from the voltage signal by using an iterative algorithm, and wherein the parameter values obtained maximize the data likelihood,
• wherein the mass spectrometer is ion cyclotron resonance mass spectrometer or a machine that measures the frequency of oscillation induced by a potential that varies harmonically in one direction.