| 摘要 |
An apparatus for filtering ions comprises: a separation device for separating ions temporally according to a first physico-chemical property; a filtering device for filtering ions according to a second physico-chemical property and comprising a first filter, the filtering device being downstream of the separator; and a control system arranged and adapted during a single cycle of separation to: operate the filtering device in a first resolving mode of operation where ions of interest are selected by the first filter; and (ii) operate the filtering device in a second non-resolving or transmission mode of operation at separation times when substantially no ions of interest are present. Also disclosed is an apparatus as above, where the first filter is a first quadrupole rod set 1 for filtering ions according to their mass to charge ratio. Also disclosed is an apparatus as above, where the filtering device comprises a pre-filter quadrupole rod set 2 and an analytical quadrupole rod set 1. Further disclosed are methods of filtering ions as performed by the above apparatuses. The apparatus for filtering ions may form part of a mass spectrometer. The present invention reduces the quantity of ions entering the analytical quadrupole and therefore reduces the contamination of the quadrupole electrode rods by filtered-out ions to the rods. |
