# US 10,121,645 B2 · Sheathless interface for capillary electrophoresis/electrospray ionization-mass spectrometry > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,121,645 B2 - Document ID: US10121645B2 - Status: Granted - Kind: B2 - Application number: 15/832,016 - Filed: 2017-12-05 - Published: 2018-06-07 - Granted: 2018-11-06 - Earliest claimed: 2016-12-05 - Assignees: National Institutes of Health (NIH) U.S. Department of Health and Human Services (DHHS), U.S. Government NIH Division of Extramural Inventions and Technology Resources (DEITR) - Applicants: The University of Kansas - Inventors: Craig E. Lunte; Ryan Tyler Johnson; Nhan To; Susan M. Lunte; Damon Osbourn - Web page: https://patentgrep.com/patent/US10121645B2 ## CPC - H01J 49/167: {Capillaries and nozzles specially adapted therefor; (electrostatic spraying per se B05B5/00)} - G01N 27/44713: {Particularly adapted electric power supply} - G01N 27/4473: {by electric means} - G01N 30/7233: {interfaced to liquid or supercritical fluid chromatograph (interfaces in general for introducing or extracting samples to be analysed with specially adapted mass spectrometer, see H01J49/04)} - H01J 49/0431: {for liquid samples (interfaces to liquid chromatographs G01N30/7233)} - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Provided herein are capillaries for use in an electrophoretic separations. The capillaries can comprise an elongated tubular wall defining a path for fluid flow from an inlet to a tapered outlet; and a decoupler junction positioned within the elongated tubular wall upstream of the tapered outlet. The decoupler junction can comprise a plurality of microchannels penetrating through the elongated tubular wall and an ion-permeable polymer coating the plurality of microchannels. Also provided are sheathless interfaces for coupling capillary electrophoresis (CE) with mass spectrometry that employ these capillaries. ## Claims ### Claim 1 A capillary for use in an electrophoretic separation, the capillary comprising: (a) an elongated tubular wall defining a path for fluid flow from an inlet to a tapered outlet; and (b) a decoupler junction positioned within the elongated tubular wall upstream of the tapered outlet; wherein decoupler junction comprises a plurality of microchannels penetrating through the elongated tubular wall and an ion-permeable polymer coating the plurality of microchannels. ### Claim 2 (depends on 1) The capillary of claim 1, wherein the ion-permeable polymer comprises a non-ionic polymer. ### Claim 3 (depends on 1) The capillary of claim 1, wherein the ion-permeable polymer comprises a hydrophilic polymer. ### Claim 4 (depends on 1) The capillary of claim 1, wherein the ion-permeable polymer comprises an ion-exchange polymer. ### Claim 5 (depends on 1) The capillary of claim 1, wherein the ion-permeable polymer comprises cellulose acetate, nafion, or a combination thereof. ### Claim 6 (depends on 1) The capillary of claim 1, wherein the ion-permeable polymer coating the plurality of microchannels has a thickness of 100 microns or less. ### Claim 7 (depends on 6) The capillary of claim 6, wherein the ion-permeable polymer coating the plurality of microchannels has a thickness of from 25 microns to 100 microns. ### Claim 8 (depends on 1) The capillary of claim 1, wherein the plurality of microchannels comprises 5 or more microchannels. ### Claim 9 (depends on 8) The capillary of claim 8, wherein the plurality of microchannels comprises from 5 to 30 microchannels. ### Claim 10 (depends on 1) The capillary of claim 1, wherein each of the plurality of microchannels are spaced apart by a distance of from 10 microns to 50 microns. ### Claim 11 (depends on 1) The capillary of claim 1, wherein the plurality of microchannels comprises at least three microchannels, and wherein each of the plurality of microchannels are spaced apart by substantially equal distances. ### Claim 12 (depends on 1) The capillary of claim 1, wherein the plurality of microchannels provide a surface area of from 2500 μm2 to 15000 μm2. ### Claim 13 (depends on 1) The capillary of claim 1, wherein the plurality of microchannels are axially spaced apart along the elongated tubular wall. ### Claim 14 (depends on 1) The capillary of claim 1, wherein the plurality of microchannels are aligned along the elongated tubular wall. ### Claim 15 (depends on 1) The capillary of claim 1, wherein each of the plurality of microchannels has a characteristic cross-sectional dimension of from 5 microns to 50 microns. ### Claim 16 (depends on 1) The capillary of claim 1, wherein the decoupler junction is positioned from 0.1 cm to 10 cm upstream of the tapered outlet. ### Claim 17 (depends on 1) A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry, the interface comprising: (a) the capillary of claim 1; (b) a buffer reservoir in liquid contact with the decoupler junction of the capillary and filed with a reservoir liquid; and (c) an electrode in contact with the reservoir liquid. ### Claim 18 (depends on 1) A method of characterizing a sample, the method comprising: (a) providing a sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry, the interface comprising: (i) the capillary of claim 1; (ii) a buffer reservoir in liquid contact with the decoupler junction of the capillary and filed with a reservoir liquid; (iii) an electrode in contact with the reservoir liquid; (iv) a mass spectrometer comprising an entrance and a detector, wherein the tapered outlet of the capillary is directed towards the entrance of a mass spectrometer; and (v) a power supply electrically connected to the electrode, wherein the power supply is configured to apply a potential across the capillary; (b) injecting the sample into the inlet of the capillary; (c) electrophoretically separating the sample; (d) directing the separated sample into the entrance of the mass spectrometer. ### Claim 19 A method of forming a capillary for use in an electrophoretic separation, the method comprising: (a) providing an electrophoretic capillary comprising an elongated tubular wall defining a path for fluid flow from a capillary inlet to a capillary outlet; (b) modifying the capillary outlet to form a tapered outlet; (c) laser ablating a plurality of microchannels penetrating through the elongated tubular wall; and (d) coating the plurality of microchannels with an ion-permeable polymer. ### Claim 20 (depends on 19) The method of claim 19, wherein modifying the capillary outlet comprises sharpening the capillary outlet to form the tapered outlet.