Mass spectrometer

摘要

A mass spectrometer is disclosed comprising a mass selective ion trap or mass analyzer arranged upstream of an ion guide. Ions are scanned out of the mass selective ion trap or mass analyzer and are received in one or more axial potential wells created or formed within the ion guide. One or more transient DC voltages or potentials are preferably applied to the ion guide in order to create a plurality of axial potential wells which are translated along the length of the ion guide. Ions are released in packets from the exit of the ion guide and are orthogonally acceleration into a drift or flight region of an orthogonal acceleration Time of Flight mass analyzer with a relatively high duty cycle.

主权项

1. A mass spectrometer comprising:
a mass selective ion trap or mass analyser for separating ions exclusively according to mass or mass to charge ratio; a first ion guide arranged downstream of said mass selective ion trap or mass analyser, said first ion guide being arranged to receive ions from said mass selective ion trap or mass analyser, and wherein said first ion guide comprises a plurality of electrodes; a first voltage supply arranged and adapted to apply one or more voltages or one or more voltage waveforms to said plurality of electrodes so that in a first mode of operation ions received from said mass selective ion trap or mass analyser are retained or confined or transported or translated in separate regions or portions of said first ion guide; a mass analyser arranged downstream of said first ion guide; and a control system arranged and adapted to switch or repeatedly switch, at least once every 10 seconds, the potential difference through which ions pass prior to entering said first ion guide between a high fragmentation mode of operation wherein ions are substantially fragmented upon entering said first ion guide and a low fragmentation mode of operation wherein substantially fewer ions are fragmented or wherein substantially no ions are fragmented upon entering said first ion guide.