Mass spectrometer having parallel precursor ion isolation

The method of any preceding claim, wherein the voltages that are applied to the mass filter are selected such that, for at least one of the mass transmission windows and at any given time, the mass transmission window is configured to cause ions having a mass to charge ratio located at the centre of the window to transmitted by the mass filter with a relatively high transmission efficiency, and to cause ions having a mass to charge ratio that is located within the window and closer to an edge of the window to be transmitted by the mass filter with a lower transmission efficiency;

• and wherein the method comprises:
• selecting a mass to charge ratio corresponding to that of one of said precursor ion species to be transmitted by the mass filter;
• and
• applying said voltages to the mass filter such that said selected mass to charge ratio is located in the mass transmission window at a position that is off-centre or proximate an edge of the mass transmission window.

The method of any preceding claim, comprising:

• selecting a set of multiple precursor ion species as being precursor ion species of interest that are to be analysed during a period in which precursor ion species are substantially continually supplied to the mass filter;
• determining that the mass filter is to be provided with a first mass transmission window during said period for transmitting a first of the multiple precursor ion species of interest;
• determining a second of the multiple precursor ion species of interest that has the closest mass to charge ratio to the first precursor ion species of interest, whilst also having an elution time from the IMS device that differs from the elution time from the IMS device of the first precursor ion species of interest by more than a pre-selected threshold value;
• determining that the mass filter is to be provided with a second mass transmission window so as to be capable of transmitting the second precursor ion species of interest;
• and
• simultaneously providing the mass filter with the first and second mass transmission windows.

A method of mass spectrometry comprising:

• providing a mass spectrometer comprising a mass filter, a mass to charge ratio separator device, a fragmentation or reaction device, and a mass analyser;
• applying voltages to the mass filter such that it simultaneously has multiple mass transmission windows that simultaneously transmit multiple respective precursor ion species to the separator device whilst filtering out other precursor ion species;
• separating, in the separator device, the precursor ion species that are simultaneously transmitted by the mass filter so as to provide different ones of the precursor ion species to the fragmentation or reaction device at different times;
• sequentially fragmenting or reacting the different precursor ion species in the fragmentation or reaction device so as to form fragment or product ions;
• detecting the fragment or product ions in the mass analyser;
• and
• associating detected fragment or product ions with their respective precursor ion species based on the times of detection of the fragment or product ions in the mass analyser.

A mass spectrometer comprising:

• a mass filter;
• a separator device, such as an ion mobility separator (IMS) device;
• a fragmentation or reaction device;
• a mass analyser;
• and
• a processor and control circuitry configured to control the spectrometer to:
• apply voltages to the mass filter such that it simultaneously has multiple mass transmission windows for simultaneously transmitting multiple respective precursor ion species to the separator device whilst filtering out other precursor ion species;
• separate, in the separator device, the precursor ion species that are simultaneously transmitted by the mass filter so as to provide different ones of the precursor ion species to the fragmentation or reaction device at different times;
• sequentially fragment or react the different precursor ion species in the fragmentation or reaction device so as to form fragment or product ions;
• detect the fragment or product ions in the mass analyser;
• and
• associate detected fragment or product ions with their respective precursor ion species based on the times of detection of the fragment or product ions in the mass analyser.

A method of mass spectrometry comprising:

• providing a mass spectrometer comprising a mass filter, a separator device, a fragmentation or reaction device, and a mass analyser;
• applying voltages to the mass filter such that it simultaneously transmits precursor ions having mass to charge ratios in a first set of mass transmission windows, whilst also simultaneously attenuating and transmitting precursor ions having mass to charge ratios in a second set of mass transmission windows;
• separating, in the separator device, precursor ion species that are simultaneously transmitted by the mass filter so as to provide different ones of the precursor ion species to the fragmentation or reaction device at different times;
• sequentially fragmenting or reacting the different precursor ion species in the fragmentation or reaction device so as to form fragment or product ions;
• detecting the fragment or product ions in the mass analyser;
• and
• associating detected fragment or product ions with their respective precursor ion species based on the times of detection of the fragment or product ions in the mass analyser.