# US 2022/0285142 A1 · Desorption ion source with post-desorption ionization in transmission geometry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2022/0285142 A1 - Document ID: US20220285142A1 - Status: Published application - Kind: A1 - Application number: 17/684,056 - Filed: 2022-03-01 - Published: 2022-09-08 - Earliest claimed: 2021-03-05 - Assignees: Bruker Daltonics, Inc. - Applicants: Bruker Daltonics GmbH & Co. KG - Inventors: Andreas HAASE; Jens HÖHNDORF; Jens BOßMEYER - Web page: https://patentgrep.com/patent/US20220285142A1 ## CPC - H01J 49/0463: {Desorption by laser or particle beam, followed by ionisation as a separate step (sample holder per se H01J49/0418)} - H01J 49/164: {Laser desorption/ionisation, e.g. matrix-assisted laser desorption/ionisation [MALDI] (sample holders H01J49/0418)} - H01J 49/24: Vacuum systems, e.g. maintaining desired pressures - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract An apparatus to generate ions from sample material deposited on a substrate which is at least partially transparent to electromagnetic waves, comprises: —a support device having a holder for the substrate, —a desorption/ionization unit including a desorption device and an ionization device, said desorption device being configured to desorb deposited sample material from a desorption site on the substrate using at least one energy burst, and said ionization device being configured to irradiate the desorbed sample material above the substrate with electromagnetic waves after the at least one energy burst, wherein the electromagnetic waves pass through the substrate before encountering the desorbed sample material at a location which corresponds to the desorption site, and —an extraction device which is arranged and designed to extract ions from the desorbed sample material and transfer them into an analyzer. The invention also relates to a correspondingly arranged method. ## Claims ### Claim 1 An apparatus to generate ions from sample material deposited on a substrate which is at least partially transparent to electromagnetic waves, comprising: a support device which has a holder for the substrate, a desorption/ionization unit which contains a desorption device and an ionization device, said desorption device being arranged and designed to desorb deposited sample material from a desorption site on the substrate using at least one energy burst, and said ionization device being arranged and designed to irradiate the desorbed sample material above the substrate with electromagnetic waves after the at least one energy burst, wherein the electromagnetic waves pass through the substrate before encountering the desorbed sample material at a location which corresponds to the desorption site, and an extraction device which is arranged and designed to extract ions from the desorbed sample material and transfer them into an analyzer. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein the support device contains a chamber in which the holder for the substrate is located, and which is arranged and designed to create a conditioned environment for the substrate including the deposited sample material. ### Claim 3 (depends on 2) The apparatus according to claim 2, wherein the chamber is connected to a vacuum source to evacuate the environment of the deposited sample material. ### Claim 4 (depends on 2) The apparatus according to claim 2, wherein the chamber is connected to a gas feed device which is arranged and designed to feed an inert buffer gas, a reactive gas, a moist gas, and/or a dopant gas which is susceptible of absorbing electromagnetic waves, into the chamber. ### Claim 5 (depends on 1) The apparatus according to claim 1, wherein the desorption device is arranged and designed to direct an energetic beam onto the deposited sample material to trigger the at least one energy burst. ### Claim 6 (depends on 5) The apparatus according to claim 5, wherein the energetic beam is a laser beam to ablate the deposited sample material. ### Claim 7 (depends on 5) The apparatus according to claim 5, wherein the energetic beam passes through the substrate at the position which corresponds to the desorption site before encountering the deposited sample material. ### Claim 8 (depends on 1) The apparatus according to claim 1, wherein the ionization device contains a laser to generate coherent electromagnetic waves, a discharge lamp, or a light-emitting diode (LED). ### Claim 9 (depends on 8) The apparatus according to claim 8, wherein the laser operates in pulsed operation or continuous-wave operation in discontinuous mode, or the discharge lamp or LED has a flash-like or continuous emission characteristic. ### Claim 10 (depends on 1) The apparatus according to claim 1, wherein the ionization device is arranged and designed to irradiate the desorbed sample material with a pulse of electromagnetic waves which is temporally coordinated with the at least one energy burst. ### Claim 11 (depends on 1) The apparatus according to claim 1, wherein the desorption device and the ionization device use a same original beam of coherent electromagnetic waves, which is conditioned to different energies for desorption/ablation and ionization. ### Claim 12 (depends on 1) The apparatus according to claim 1, wherein the extraction device includes at least one deflection electrode, which is arranged and designed so that extracted ions change their direction of motion at least once. ### Claim 13 A method to generate ions from sample material, comprising: depositing the sample material on a substrate which is at least partially transparent to electromagnetic waves, desorbing the deposited sample material from a desorption site on the substrate using at least one energy burst, ionizing particles and/or molecules in the desorbed sample material above the substrate after the at least one energy burst by irradiating them with electromagnetic waves which pass through the substrate at a position which corresponds to the desorption site before they encounter the desorbed sample material, and extracting ions from the desorbed sample material and transferring them into an analyzer. ### Claim 14 (depends on 13) The method according to claim 13, wherein the sample material comprises a tissue section, a homogenate, or individual material deposits on the substrate.