US 11,705,317 B2
Optimised targeted analysis
Martin Raymond Green, Bowdon (GB); Jason Lee Wildgoose, Stockport (GB); and Keith Richardson, High Peak (GB)
Assigned to Micromass UK Limited, Wilmslow (GB)
Filed by Micromass UK Limited, Wilmslow (GB)
Filed on Nov. 5, 2021, as Appl. No. 17/519,747.
Application 17/519,747 is a continuation of application No. 16/604,538, granted, now 11,201,043, previously published as PCT/GB2018/050968, filed on Apr. 11, 2018.
Claims priority of application No. 1705908 (GB), filed on Apr. 12, 2017.
Prior Publication US 2022/0059330 A1, Feb. 24, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H01J 49/00 (2006.01); G01N 30/72 (2006.01)
CPC H01J 49/0031 (2013.01) [G01N 30/7233 (2013.01); H01J 49/0045 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method of mass spectrometry comprising:
a) using a separator device to chromatographically separate compounds in an analytical sample and ionising the eluting sample and/or separating precursor ions, so as to provide temporally separated precursor ions;
b) repeatedly alternating between first and second modes as analyte elutes from the separator device, wherein in the first mode the precursor ions are subjected to fragmentation or reaction conditions such that a relatively low proportion or no precursor ions dissociate, and in the second mode the precursor ions are subjected to fragmentation or reaction conditions such that a relatively high proportion or all precursor ions dissociate to form product ions;
c) mass analysing the precursor ions in the first mode;
d) in the second mode, mass analyzing each of the product ions with a time of flight mass analyser during a plurality of sequential acquisition periods so as to obtain mass spectral data, wherein value(s) of one or more operational parameters of the time of flight mass analyser is/are varied such that the one or more operational parameters has/have different values during the different acquisition periods, and wherein the mass spectral data obtained for a given product ion varies depending on the value(s) of said one or more operational parameters;
e) storing the mass spectral data obtained in each acquisition period along with its respective value(s) of said one or more operational parameters used in obtaining the mass spectral data;
f) interrogating the stored mass spectral data for at least one of the product ions, and determining which of the mass spectral data for that product ion meets a predetermined criterion, and determining the value of each of said one or more operational parameters that provides this mass spectral data as a target operational parameter value; and
g) in the second mode, mass analyzing again said at least one of the product ions, wherein during this analysis the value(s) of said one or more operational parameter is/are set to its respective target operational parameter value(s) for said at least one of the product ions.