US 11,908,672 B2
Precursor accumulation in a single charge state in mass spectrometry
Takashi Baba, Richmond Hill (CA); Pavel Ryumin, Toronto (CA); and Igor Chemushevich, Toronto (CA)
Assigned to DH Technologies Development Pte.Ltd., Singapore (SG)
Appl. No. 17/255,597
Filed by DH TECHNOLOGIES DEVELOPMENT PTE. LTD., Singapore (SG)
PCT Filed Aug. 15, 2019, PCT No. PCT/IB2019/056935
§ 371(c)(1), (2) Date Dec. 23, 2020,
PCT Pub. No. WO2020/044159, PCT Pub. Date Mar. 5, 2020.
Claims priority of provisional application 62/724,495, filed on Aug. 29, 2018.
Prior Publication US 2021/0272787 A1, Sep. 2, 2021
Int. Cl. H01J 49/00 (2006.01); H01J 49/06 (2006.01); H01J 49/16 (2006.01); H01J 49/42 (2006.01)
CPC H01J 49/0077 (2013.01) [H01J 49/0031 (2013.01); H01J 49/063 (2013.01); H01J 49/165 (2013.01); H01J 49/4215 (2013.01)] 15 Claims
OG exemplary drawing
 
1. Apparatus for reducing the charge of precursor ions of the same compound that have different mass-to-charge ratio (m/z) values in order to continuously accumulate and transmit the precursor ions at a single m/z value, comprising:
an ion source device for ionizing a compound of a sample, producing two or more precursor ions of the compound with different m/z values;
a reagent source device that supplies charge reducing reagent;
a mass filter device; and
an ion guide device positioned between the mass filter device and both the ion source device and the reagent source device that receives the two or more precursor ions from the ion source device and the charge reducing reagent from the reagent source device, applies an alternating current (AC) voltage and a direct current (DC) voltage to one or more electrodes of the ion guide device that creates a pseudopotential to trap the received two or more precursor ions with m/z values below a threshold m/z in the ion guide device and to, in turn, cause the trapped two or more precursor ions to be charge reduced by the received charge reducing reagent so that m/z values of the two or more precursor ions increase to a single m/z value above the threshold m/z, and applies the DC voltage to the one or more electrodes relative to a DC voltage applied to electrodes of the mass filter device that causes the two or more precursor ions with m/z values increased to the single m/z value to be continuously transmitted to the mass filter device.