Method and apparatus for data independent combined ion mobility and mass spectroscopy analysis

A method of data independent combined ion mobility and mass spectroscopy analysis, comprising the following steps:

• introducing precursor ions into an ion mobility separator (IMS), sequentially releasing precursor ions from said IMS according to their ion mobility,
• introducing said released precursor ions into a mass filter which selectively transmits precursor ions having m/z values falling within a controllable mass window,
• fragmenting the precursor ions transmitted through said mass filter to generate fragment ions,
• carrying out a mass spectroscopy measurement on said fragment ions, wherein each fragment ion is associated with a mass window and an ion mobility (IM) range, and associating detected fragments with its corresponding precursor ion,
• wherein said IMS and said mass filter are controlled in a synchronized manner such as to carry out a plurality of IM scans, during which precursor ions of increasing or decreasing IM are successively released from said IMS, and during which the mass window of said mass filter is shifted continuously or stepwisely towards lower or higher m/z values, respectively, wherein in said IM scans, adjacent mass windows that are associated with consecutive mass spectroscopy measurements of fragment ions overlap, such that the precursor ions transmitted through said mass filter during one IM scan are located in at least one continuous scan region in an m/z-IM plane which extends in a generally diagonal direction in said m/z-IM plane,
• wherein adjacent scan regions associated with different IM scans overlap in the m/z-direction,
• and wherein said step of associating a detected fragment with its corresponding precursor ion is based on determining or utilizing the corresponding mass windows and IM ranges associated with various occurrences of said fragment in said mass spectrometry measurement.