Method for calibrating a Fourier transform ion cyclotron resonance mass spectrometer

A method for improving the calibration of a Fourier transform ion cyclotron resonance mass spectrometer wherein the frequency spectrum of a sample has been measured and the frequency (f) and intensity (I) of at least three species having known mass to charge (m/z) ratios and one specie having an unknown (m/z) ratio have been identified, comprising the steps of:

• a) using the known (m/z) ratios, frequencies, and intensities of the at least three species, calculating coefficients A, B, and C, wherein the mass to charge ratio of a least one of the three species (m/z)i is equal to A f i + B f i 2 + C · ( I i ) f i 2
• wherein fi is the detected frequency of the specie, Ii is the intensity of the specie, and
• b) using the calculated values for A, B, and C, calculating the mass to charge ratio of the unknown specie (m/z)ii as the sum of A f ii + B f ii 2 + C · ( I ii ) f ii 2
• wherein fii is the measured frequency of the unknown specie, and (Iii) is the measured intensity of the unknown specie.

A method for improving the calibration of a Fourier transform ion cyclotron resonance mass spectrometer wherein the frequency spectrum of a sample has been measured and the frequency (f) and intensity (I) of at least three species having known mass to charge (m/z) ratios and one specie having an unknown (m/z) ratio have been identified, comprising the steps of:

• a) using the known (m/z) ratios, frequencies, and intensities of the at least three species, calculating coefficients A, B, and C, wherein the mass to charge ratio of a least one of the three species (m/z)i is equal to A f i + B f i 2 + C · ln ⁡ ( I i ) f i 3
• wherein fi is the detected frequency of the specie, Ii is the intensity of the specie, and
• b) using the calculated values for A, B, and C, calculating the mass to charge ratio of the unknown specie (m/z)ii as the sum of A f ii + B f ii 2 + C · ln ⁡ ( I ii ) f ii 3
• wherein fii is the measured frequency of the unknown specie, and (Iii) is the measured intensity of the unknown specie.