# US 9,005,526 B2 · Narrow bore porous layer open tube capillary column and uses thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,005,526 B2 - Document ID: US9005526B2 - Status: Granted - Kind: B2 - Application number: 14/048,378 - Filed: 2013-10-08 - Published: 2014-02-06 - Granted: 2015-04-14 - Earliest claimed: 2006-06-21 - Assignees: Northeastern University - Applicants: Northeastern University - Inventors: Barry L. Karger; Jian Zhang - Web page: https://patentgrep.com/patent/US9005526B2 ## CPC - G01N 30/60: Construction of the column - B01J 20/28085: {being more than 50 nm, i.e. macropores} - B01J 20/285: based on polymers - B01J 20/289: bonded via a spacer - B01J 20/327: {Polymers obtained by reactions involving only carbon to carbon unsaturated bonds} - B01J 20/3282: {Crosslinked polymers} - G01N 30/6073: {in open tubular form} - B01J 2220/54: Sorbents specially adapted for analytical or investigative chromatography - B01J 2220/84: Capillaries - B01J 2220/86: Sorbents applied to inner surfaces of columns or capillaries - G01N 30/7266: {by electric field, e.g. electrospray} - G01N 2030/528: {Monolithic sorbent material} - Y10T 436/11: Automated chemical analysis - Y10T 436/117497: with a continuously flowing sample or carrier stream - 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) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A polymer-based PLOT capillary column prepared by in situ copolymerization of a functional monomer and a crosslinking monomer, which enhances the strength of the polymer matrix, is disclosed. Also disclosed is a system comprising the polymer-based PLOT column coupled to a mass flow or concentration sensitive detector, for carrying out a chemical analysis method on samples separated by liquid chromatography using the column, and a process for using the system. Columns of the invention can be prepared in a robust fashion with a very narrow i.d., e.g., 5-15 μm. Thus, they are suitable for commercial use in ultratrace LC/MS proteomic analysis. Columns according to the invention are characterized by high resolving power and high column-to-column reproducibility. When these columns are coupled on-line with, e.g., ESI-MS detection, the resulting systems are capable of detecting the component parts of complex proteomic samples down to the low attomole to sub-attomole level. ## Claims ### Claim 1 A porous layer open tube (PLOT) capillary column or channel in a microfabricated device for carrying out a chemical analysis of a sample, said column or channel comprising: a rigid porous layer separation medium comprising a crosslinked, macroporous, organic polymeric stationary phase layer covalently attached to an inner wall surface of said column or channel, wherein said organic polymeric stationary phase layer is from 0.5-3 μm in thickness; an open unfilled bore inside said rigid porous layer, wherein said open bore is disposed around a central axis of said column or channel and extends the length of said column or channel; wherein said column or channel has an inner diameter of 15 μm or less. ### Claim 2 (depends on 1) The column or channel of claim 1, wherein the retention time of an analyte for a plurality of said columns or channels varies less than 10% during use in high performance liquid chromatography. ### Claim 3 (depends on 2) The column or channel of claim 2, wherein the retention time of an analyte for a plurality of said columns or channels varies less than 5% during use in high performance liquid chromatography. ### Claim 4 (depends on 1) The column or channel of claim 1 that has a length of one meter or more. ### Claim 5 (depends on 4) The column or channel of claim 4 that has a length of three meters or more. ### Claim 6 (depends on 1) The column or channel of claim 1, wherein said organic polymeric stationary phase layer attached to the inner wall surface of said column or channel comprises styrenic, methacrylic or acrylic monomeric units, or combinations thereof. ### Claim 7 (depends on 6) The column or channel of claim 6, wherein said organic polymeric stationary phase layer attached to the inner wall surface of said column or channel comprises styrene and divinylbenzene monomer units. ### Claim 8 (depends on 7) The column or channel of claim 7, wherein said organic polymeric stationary phase layer is poly(styrene-divinylbenzene). ### Claim 9 (depends on 6) The column or channel of claim 6, wherein said organic polymeric stationary phase layer comprises (C4-C18) alkyl methacrylate monomer units. ### Claim 10 (depends on 6) The column or channel of claim 6, wherein said organic polymeric stationary phase layer is devoid of charged functional groups. ### Claim 11 (depends on 1) The column or channel of claim 1, wherein said organic polymeric stationary phase layer is thermally stable to 250° C. ### Claim 12 (depends on 1) The column or channel of claim 1, that has an inner diameter of 10 μm or less. ### Claim 13 (depends on 1) The column or channel of claim 1, that is capable of a flow rate of 5-50 nL/min at 6000 psi or less during high performance liquid chromatography. ### Claim 14 (depends on 1) The column or channel of claim 1 made by a process comprising: adding to a column or channel a mixture comprising: a functional monomer selected from the group consisting of styrenic monomers, methacrylic monomers, acrylic monomers, and combinations thereof; a crosslinker compatible with said functional monomer; a polar porogenic solvent; and an initiator for thermal or UV induced polymerization; and polymerizing the mixture in the column or channel to form said macroporous, organic polymeric stationary phase layer as said porous layer open tube separation medium attached to the inner surface of the column or channel. ### Claim 15 A system for carrying out a chemical analysis of a sample, the system comprising: a porous layer open tube (PLOT) capillary column or channel in a microfabricated device, the column or channel comprising: a rigid porous layer separation medium comprising a crosslinked, macroporous, organic polymeric stationary phase layer covalently attached to an inner wall surface of said column or channel, wherein said organic polymeric stationary phase layer is from 0.5-3 μm in thickness; an open unfilled bore inside said rigid porous layer, wherein said open bore is disposed around a central axis of said column or channel and extends the length of said column or channel; wherein said column or channel has an inner diameter of 15 μm or less; and a mass-flow or concentration sensitive detector coupled with an interface to an exit end of said column or channel, wherein said interface is an electrospray ionization (ESI) interface or a matrix assisted laser desorption ionization (MALDI) interface. ### Claim 16 (depends on 15) The system of claim 15, wherein said detector is a mass spectrometer, a fluorescence detector, an electro-chemiluminescence detector or a nuclear magnetic resonance detector. ### Claim 17 (depends on 15) The system of claim 15, wherein said interface is an electrospray ionization (ESI) interface and said detector is a mass spectrometer. ### Claim 18 (depends on 15) The system of claim 15, wherein said interface is a matrix assisted laser desorption ionization (MALDI) interface and said detector is a mass spectrometer. ### Claim 19 (depends on 15) The system of claim 15, further comprising a preparatory pre-column coupled to an entrance end of said PLOT column or channel. ### Claim 20 (depends on 15) The system of claim 15, wherein said organic polymeric stationary phase layer attached to the inner wall surface of said column or channel comprises styrenic, methacrylic or acrylic monomeric units, or combinations thereof. ### Claim 21 (depends on 20) The system of claim 20, wherein said organic polymeric stationary phase layer attached to the inner wall surface of said column or channel comprises styrene and divinylbenzene monomer units. ### Claim 22 (depends on 21) The system of claim 21, wherein said organic polymeric stationary phase layer is poly(styrene-divinylbenzene). ### Claim 23 (depends on 20) The system of claim 20, wherein said organic polymeric stationary phase layer comprises (C4-C18) alkyl methacrylate monomer units. ### Claim 24 (depends on 20) The system of claim 20, wherein said organic polymeric stationary phase layer is devoid of charged functional groups. ### Claim 25 (depends on 15) The system of claim 15, wherein said organic polymeric stationary phase layer is thermally stable to 250° C. ### Claim 26 (depends on 15) The system of claim 15, wherein the inner diameter of said column or channel is 10 μm or less. ### Claim 27 (depends on 15) The system of claim 15, wherein said column is capable of a flow rate of 5-50 nL/min at 6000 psi or less during high performance liquid chromatography. ### Claim 28 (depends on 1) The column or channel of claim 1, wherein the stationary phase layer is formed by copolymerization of a first monomer and a second monomer. ### Claim 29 (depends on 28) The column or channel of claim 28, wherein the first monomer has retentive properties. ### Claim 30 (depends on 28) The column or channel of claim 28, wherein the second monomer forms crosslinks during copolymerization.