| abstract |
Abstract: An ion mobility mass analyzer (300) includes an ion source region (32) connected to an ion mobility analyzer having an ion outlet connected to a quadrupole mass filter (304). The outlet of the filter is connected to a collision cell (304) having an ion outlet connected to an ion acceleration region of a mass analyzer (36), such as a time-of-flight mass analyzer. Apparatus (300) is well suited for technol- ogy for sequencing analysis in which a three-dimensional ion spectrum (ion mobility versus ion intensity versus ion mass) is generated as the sample is ionized. If the spectrum does not show ion overlap at multiple mobility values, the collision cell (304) is filled with buffer gas (306) and the device (300) is reactivated, thereby causing the parent and daughter ions to be recharged. A complete three-dimensional spectrum results. However, if the initial spectrum indicates that two or more ions overlap at multiple mobility values, the collision cell (304) is filled with buffer gas (306) and the quadrupole mass filter ( 302) is controlled so as to selectively filter out all ions other than one type of ion having a value of the mobility which overlaps. The device (300) is reactivated and the quadrupole mass filter (302) is selectively controlled as many times as the mobility overlaps, thereby providing a complete three-dimensional spectrum of the parent and daughter ions produced by the subdivision. give. Various arrangements of the mass filter (302), ion trap (32) and collision cell (304) for the ion mobility (34) and mass analyzer (36) are possible. |