METHOD OF MASS SELECTION OF IONS IN TANDEM LINEAR QUADRUPOLE MASS SPECTROMETERS Russian patent published in 2025 - IPC H01J49/32 

FIELD: electricity.

SUBSTANCE: invention relates to tandem quadrupole mass spectrometry and can be used for mass analysis of isotopes with high mass numbers. Method of mass selection of ions in tandem linear quadrupole mass spectrometers consists in successive action of variable high-frequency quadrupole fields in planes of XOY on ions moving orthogonal to these planes with their pre-filtration during passage of the first quadrupole and their registration at the output of the second quadrupole. Alternating high-frequency field of the second quadrupole is generated with phase modulation of the type cos(ωt+εsin[ω_mt]), where ε is amplitude coefficient of phase modulation, ω is frequency of alternating voltage, ω_m is modulation frequency at deviation of modulation frequency not exceeding 20 % of frequency of action on ions. Value of the voltage of the second quadrupole forming the constant field lies in range from 0.157 to 0.176 of the amplitude of the alternating voltage.

EFFECT: limiting the width of the pass band of ions.

1 cl, 2 dwg