Mass spectrometer including multiple mass analysis stages and method of operation, to give improved resolution

A method of operating a spectrometer apparatus including a first Wien filter stage and a second Wien filter stage, the method comprising:

• (1) applying electric fields and magnetic fields in the first and second stages, to scan the first and second Wien filter stages, whereby both the first and second spectrometer stages operate in a resolving mode for ions with the same mass to charge ratio;
• (2) generating a stream of ions and passing the stream of ions through the first Wien filter stage and subsequently the second Wien filter stage, and detecting ions exiting the second Wien filter stage;
• (3) obtaining a peak shape from the ions exiting the second Wien filter stage, the peak shape having at least one of higher resolution than the resolution of either one of the first and second Wien filter stages sets and less peak tailing than either one of the first and second Wien filter stages.

A method of operating a spectrometer apparatus including a first spectrometer stage and a second spectrometer stage, the method comprising:

• (1) applying at least one of electric fields and magnetic fields in the first and second spectrometer stages, to scan the first and second spectrometer stages;
• (2) generating a stream of ions and passing the stream of ions through the first spectrometer stage and subsequently through the second spectrometer stage, and detecting ions exiting the second spectrometer stage;
• (3) obtaining a peak shape from the ions exiting the second spectrometer stage, wherein the first and second spectrometer stages are operated in a resolving mode for a selected mass, wherein a mass shift is provided between the selected masses of the first and second spectrometer stages and an overlap is provided between the peak shapes of the first and second spectrometer stages, whereby the peak shape obtained at the exit of the second spectrometer stage has at least one of higher resolution than the resolution of either one of the first and second spectrometer stage sets and less peak tailing than either one of the first and second spectrometer stages.