Nonreactive inlet splitter for gas chromatography and method

Claim 2

In an inlet splitter for a gas chromatograph, a body having aligned injector and mixing chambers, means to heat said body and said chambers, elongate means forming an inert pathway between said injector and mixing chambers, said elongate means having an inlet in said injector chamber, and a baffled outlet opening to an expansion zone in said mixing chamber, means injecting an analysis sample into the inert pathway of said elongate means, means introducing a continuous flow of carrier gas to said inert pathway of said elongate means, said carrier gas serving to pick up, vaporize and convey injected sample through said electronic means and baffled outlet to said expansion zone, means forming a part of a gas chromatograph to withdraw a linear aliquot of intermixed sample and carrier gas from said expansion zone, and discharge means to effect removal of excess quantities of intermixed sample and carrier gas from said expansion zone and mixing chamber.

Claim 3

An inlet splitter as in claim 1 wherein at least a portion of said inert pathway within said elongate means is substantially filled with an inert subdivided packing.

Claim 4

An inlet splitter as in claim 2 wherein said inert subdivided packing is in the form of a very fine inert glass beads.

Claim 5

An inlet splitter as in claim 3 wherein said glass beads are of a particle size whereby 100% pass through a 100-mesh screen and 100% are retained on a 120-mesh screen, U.S. Standard Series.

Claim 6

An inlet splitter as in claim 2 including plug means formed of inert filaments to hold said inert packing in place within the inert pathway of said elongate means.

Claim 7

An inlet splitter as in claim 5 wherein said inert plugs are formed of glass wool.

Claim 8

An inlet splitter as in claim 1 wherein said elongate means and the injector and mixing chambers of the body are in substantially axial alignment with one another.

Claim 9

An inlet splitter as in claim 7 wherein said elongate means comprises an elongate glass tube with flow baffles at the end thereof.

Claim 10

An inlet splitter as in claim 8 including means to sealingly support said elongate glass tube in axial alignment within said injector and mixing chamber.

Claim 11

An inlet splitter as in claim 1 wherein the baffled outlet end of said elongate means includes an inner flow reversing cup means and an outer flow reversing cup means which cooperate to effect intermixing of the carrier and sample gases and discharge of the same into said expansion zone.

Claim 12

An inlet splitter as in claim 10 wherein all components of said elongate means are integrally constructed of glass.

Claim 13

An inlet splitter as in claim 1 wherein said means introducing a continuous flow of carrier gas includes flow control means regulating the pressure of the gas and conduit means extending through said body to said injector chamber.

Claim 14

An inlet splitter as in claim 1 wherein said means forming part of a gas chromatograph is the inlet end of a capillary chromatograph column extending into and positioned within said mixing chamber.

Claim 15

In an inlet splitter for a gas chromatograph, a body having aligned injector and mixing chambers, means to heat said body and said chambers, elongate means forming an inert pathway between said injector and mixing chambers, said elongate means having an inlet end in said injector chamber and a baffled outlet end forming an expansion zone in said mixing chamber, means lining said injector chamber and forming an inert annular pathway surrounding said elongate means, means injecting an analysis sample into one of said inert pathways of said injector chamber, means introducing a continuous flow of carrier gas to said pathways to flow through said inert annular pathway and into said inert elongate pathway, said carrier gas serving to pick up, vaporize and convey injected sample through said elongate means and baffled outlet to said expansion zone, means forming a part of a gas chromatograph to withdraw a linear aliquot of intermixed sample and carrier gas from said expansion zone, and discharge means to effect removal of excess quantities of intermixed sample and carrier gas from said expansion zone and mixing chamber.

Claim 16

In an inlet splitter for a gas chromatograph, a body having aligned injector and mixing chambers, means to heat said body and said chambers, elongate means forming an inert pathway between said injector and mixing chambers, said elongate means having an inlet end in said injector chamber and a baffled outlet end forming an expansion zone in said mixing chamber, means lining said injector chamber and forming an inert annular pathway surrounding said elongate means, means injecting an analysis sample into one of said inert pathways of said injector chamber, means introducing a continuous flow of carrier gas to said pathways to flow through said inert annular pathway and into said inert elongate pathway, said carrier gas serving to pick up, vaporize and convey injected sample through said elongate means and baffled outlet to said expansion zone, means forming a part of a gas chromatograph to withdraw a linear aliquot of intermixed sample and carrier gas from said expansion zone, and discharge means to effect removal of excess quantities of intermixed sample and carrier gas from said expansion zone and mixing chamber.

Claim 17

An inlet splitter as in claim 14 wherein said means lining the injector chamber includes an end wall having a small instrument opening therein for injection of said analysis sample.

Claim 18

An inlet splitter as in claim 14 wherein all components of said lining means are constructed of glass.

Claim 19

A substantially nonreactive linear inlet splitter for a gas chromatograph, comprising an elongate body, said body being provided with first and second substantially cylindrical interior passages, each having inlet and outlet ends, the outlet end of said first interior passage coinciding with the inlet end of said second interior passage, said second interior passage being of sufficient diameter to axially receive the inlet end of a chromatograph column, said body having a relatively small instrument opening adjacent the inlet end of said first interior passage, a self-sealing septum adjacent said instrument opening, removable closure means for the end of said interior passage, said closure means having a needle aperture therein in alignment with the instrument opening in said body to thereby facilitate introduction of an analysis sample, substantially inert tubular liner means extending from a position closely adjacent said instrument opening to a position within said second interior passage means, said inert tubular lining means being removably supported in axially aligned relation within said first and second interior passages by demountable sealing means associated with said body, said tubular lining means providing a substantially inert pathway within said tubular liner means, means for introducing carrier gas to said inert pathway within said tubular liner so that the same passes through and along the length of said pathway within said tubular liner means, the portion of the tubular liner means within said second interior passage of the body being provided with baffle means to effect simultaneous reversal of direction and mixing of carrier and analysis sample gases passing therethrough, removable closure means for the outlet end of second interior passage of the body, said last named means including means to axially receive and support the inlet end of said chromatograph column so that the latter extends into the interior of said interior passage of the body, and means for controllably withdrawing excess amounts of intermixed carrier and analysis sample gases from said second interior passage of the body, whereby a sample introduced through said needle aperture is introduced within said inert pathway within said tubular liner where it is immediately picked up by carrier gas, intermixed with the same and introduced directly as a linear aliquot to the inlet end of said chromatograph column with contact being had only with the inert surfaces of said tubular liner.

Claim 20

A substantially nonreactive linear inlet splitter for a gas chromatograph, comprising an elongate body, said body being provided with first and second substantially cylindrical interior passages, each having inlet and outlet ends, the outlet end of said first interior passage coinciding with the inlet end of said second interior passage, said second interior passage being of sufficient diameter to axially receive the inlet end of a chromatograph column, said body having a relatively small instrument opening adjacent the inlet end of said first interior passage, a self-sealing septum adjacent said instrument opening, removable closure means for the end of said interior passage, said closure means having a needle aperture therein in alignment with the instrument opening in said body to thereby facilitate introduction of an analysis sample, substantially inert tubular liner means extending from a position closely adjacent said instrument opening to a position within said second interior passage means, said inert tubular lining means being removably supported in axially aligned relation within said first and second interior passages by demountable sealing means associated with said body, said tubular lining means providing a substantially inert pathway within said tubular liner means, means for introducing carrier gas to said inert pathway within said tubular liner so that the same passes through and along the length of said pathway within said tubular liner means, the portion of the tubular liner means within said second interior passage of the body being provided with baffle means to effect simultaneous reversal of direction and mixing of carrier and analysis sample gases passing therethrough, removable closure means for the outlet end of second interior passage of the body, said last named means including means to axially receive and support the inlet end of said chromatograph column so that the latter extends into the interior of said interior passage of the body, and means for controllably withdrawing excess amounts of intermixed carrier and analysis sample gases from said second interior passage of the body, whereby a sample introduced through said needle aperture is introduced within said inert pathway within said tubular liner where it is immediately picked up by carrier gas, intermixed with the same and introduced directly as a linear aliquot to the inlet end of said chromatograph column with contact being had only with the inert surfaces of said tubular liner.

Claim 21

An inlet splitter as in claim 17 wherein said elongate body is provided with heating means to establish a temperature within said first and second interior passages which is optimum for sample vaporization and mixing with said carrier gas.

Claim 22

An inlet splitter as in claim 17 wherein said demountable sealing means comprises a compressible sealing ring and a cooperating threaded member for supporting said inert tubular liner means.

Claim 23

An inlet splitter as in claim 17 wherein said means for introducing carrier gas includes a radially extending conduit in said body and means for preheating the carrier gas introduced to said conduit means.

Claim 24

An inlet splitter as in claim 18 wherein said means for preheating the carrier gas comprises tubular conduit means encircling said body so as to be heated by said heating means for the body.

Claim 25

An inlet splitter as in claim 17 wherein said chromatographic column has a diameter substantially less than the diameter of said second substantially cylindrical interior passage, the ratio of said diameters serving to control the aliquot portion of intermixed sample and carrier gas introduced to said chromatograph column.

Claim 26

An inlet splitter as in claim 17 wherein said means for controllably withdrawing intermixed carrier and sample gas comprises a radial discharge conduit leading from said second interior passage to the exterior of said elongate body, and means cooperating therewith for controlling the proportion of intermixed carrier gas and sample discharged through said radial discharge conduit.

Claim 27

A substantially nonreactive linear inlet splitter for a gas chromatograph, comprising an elongate body, said body being provided with first and second substantially cylindrical interior passage, each having inlet and outlet ends, the outlet end of said first interior passage coinciding with the inlet end of said second interior passage, said second interior passage being of sufficient diameter to axially receive the inlet end of a chromatograph column, a substantially inert injector cap lining said first interior passage, said injector cap having an end wall with a relatively small instrument opening adjacent the inlet end of said first interior passage, a self-sealing septum adjacent the end wall of said inert injector cap, removable closure means for the end of said interior passage, said closure means having a needle aperture therein in alignment with the instrument opening in said inert injector cap to thereby facilitate introduction of an analysis sample within said injector cap, substantially inert tubular liner means extending from a position closely adjacent said instrument opening within said injector cap to a position within said second interior passage means, said inert tubular lining means being removably supported in axially aligned relation within said first and second interior passages, said injector cap and tubular lining means cooperating within said first interior passage means to provide a substantially inert annular pathway surrounding said tubular lining means and communicating with a substantially inert pathway within said tubular liner means, means for introducing carrier gas to said annular pathway between the injector cap and tubular liner so that the same passes through the pathway within said tubular liner means, the portion of the tubular liner means within said second interior passage of the body being provided with baffle means to effect simultaneous reversal of direction and mixing of carrier and analysis sample gases passing therethrough, removable closure means for the outlet end of second interior passage of the body, said last named means including means to axially receive and support the inlet end of said chromatograph column so that the latter extends into the interior of said interior passage of the body, and means for controllably withdrawing excess amounts of intermixed carrier and analysis sample gases from said second interior passage of the body, whereby a sample introduced through said needle aperture is immediately picked up by carrier gas, intermixed with the same and introduced directly as a linear aliquot to the inlet end of said chromatograph column with contact being had only with the inert surfaces of said injector cap and tubular liner.

Claim 28

A substantially nonreactive linear inlet splitter for a gas chromatograph, comprising an elongate body, said body being provided with first and second substantially cylindrical interior passage, each having inlet and outlet ends, the outlet end of said first interior passage coinciding with the inlet end of said second interior passage, said second interior passage being of sufficient diameter to axially receive the inlet end of a chromatograph column, a substantially inert injector cap lining said first interior passage, said injector cap having an end wall with a relatively small instrument opening adjacent the inlet end of said first interior passage, a self-sealing septum adjacent the end wall of said inert injector cap, removable closure means for the end of said interior passage, said closure means having a needle aperture therein in alignment with the instrument opening in said inert injector cap to thereby facilitate introduction of an analysis sample within said injector cap, substantially inert tubular liner means extending from a position closely adjacent said instrument opening within said injector cap to a position within said second interior passage means, said inert tubular lining means being removably supported in axially aligned relation within said first and second interior passages, said injector cap and tubular lining means cooperating within said first interior passage means to provide a substantially inert annular pathway surrounding said tubular lining means and communicating with a substantially inert pathway within said tubular liner means, means for introducing carrier gas to said annular pathway between the injector cap and tubular liner so that the same passes through the pathway within said tubular liner means, the portion of the tubular liner means within said second interior passage of the body being provided with baffle means to effect simultaneous reversal of direction and mixing of carrier and analysis sample gases passing therethrough, removable closure means for the outlet end of second interior passage of the body, said last named means including means to axially receive and support the inlet end of said chromatograph column so that the latter extends into the interior of said interior passage of the body, and means for controllably withdrawing excess amounts of intermixed carrier and analysis sample gases from said second interior passage of the body, whereby a sample introduced through said needle aperture is immediately picked up by carrier gas, intermixed with the same and introduced directly as a linear aliquot to the inlet end of said chromatograph column with contact being had only with the inert surfaces of said injector cap and tubular liner.

Claim 29

An inlet splitter as in claim 24 wherein said inert tubular liner means is provided with an outlet end positioned intermediate the ends of said second interior passage, first rearwardly extending inert cup means surrounding said outlet end, and second forwardly facing inert cup means surrounding said outlet end and said rearwardly facing cup means, said cup means providing mixing chambers for effecting reversal of direction and mixing of said carrier and sample gases passing through said inert tubular liner means.

Claim 30

An inlet splitter as in claim 25 wherein said second forwardly facing cup means has a forwardly extending cylindrical portion which forms an expansion and splitting chamber surrounding the inlet end of said chromatograph column.

Claim 31

An inlet splitter as in claim 24 wherein said injector cap and inert tubular liner means are fabricated of glass.

Claim 32

A glass inlet splitter for providing substantially linear sample fractionation for a capillary gas chromatograph, comprising an elongate body having at least two axially aligned substantially cylindrical interior passages, the first one of said interior passages having a sample receiving inlet end and a gas delivery outlet end, the second one of said interior passages having an inlet end coinciding with the outlet end of said first interior passage and an outlet end in substantially axial alignment with the inlet end of said capillary gas chromatograph, means for delivering an analysis sample to said first interior passage, said last named means including an apertured sample port and a self-sealing septum, means for introducing the carrier gas to said first interior passage including conduit means in said elongate body adjacent the outlet end of said first interior passage, means for mixing a sample with the carrier gas for delivery to said second interior passage, said mixing and delivery means including an elongate glass tube extending between said first and second interior passages and a glass injector cap lining the interior surfaces of said first interior passage, said injector cap having an end wall with a relatively small instrument opening in axial alignment with the aperture in said sample port, mounting and sealing means positioned in the coinciding outlet and inlet end of said first and second interior passages, said mounting and sealing means supporting said elongate glass tube in axial aligned relation within said first and second interior passages, mounting and sealing means closing the outlet end of said second interior passage, said last named means supporting said capillary chromatograph column so that the inlet end thereof is positioned within said second interior passage, glass baffle means supported within said second interior passage adjacent an outlet end of said elongate glass tube, said glass baffle means including an outer forwardly directed substantially cylindrical cup means and an inner rearwardly directed cup means, said rearwardly directed cup means surrounding an outlet end of said glass tube so as to effect mixing and reversal of direction of gases discharged by said elongate glass tube, said outer forwardly directed cup means surrounding said inner cup means so as to effect a mixing and reversal of gases discharged from said inner cup means, said outer cup means including a substantially cylindrical portion concentrically surrounding the inlet end of said capillary chromatograph column, and means for controllably withdrawing excess amounts of intermixed carrier gas and sample from said second interior passage, whereby sample introduced through said sample port is picked up by carrier gas adjacent the small instrument opening of said glass injector cap, intermixed with the same within said elongate glass baffle means and introduced directly as a linear aliquot to the inlet end of said capillary chromatograph with contact being had only with the inner surfaces of the injector cap, elongate tube and baffle means.

Claim 33

A glass inlet splitter for providing substantially linear sample fractionation for a capillary gas chromatograph, comprising an elongate body having at least two axially aligned substantially cylindrical interior passages, the first one of said interior passages having a sample receiving inlet end and a gas delivery outlet end, the second one of said interior passages having an inlet end coinciding with the outlet end of said first interior passage and an outlet end in substantially axial alignment with the inlet end of said capillary gas chromatograph, means for delivering an analysis sample to said first interior passage, said last named means including an apertured sample port and a self-sealing septum, means for introducing the carrier gas to said first interior passage including conduit means in said elongate body adjacent the outlet end of said first interior passage, means for mixing a sample with the carrier gas for delivery to said second interior passage, said mixing and delivery means including an elongate glass tube extending between said first and second interior passages and a glass injector cap lining the interior surfaces of said first interior passage, said injector cap having an end wall with a relatively small instrument opening in axial alignment with the aperture in said sample port, mounting and sealing means positioned in the coinciding outlet and inlet end of said first and second interior passages, said mounting and sealing means supporting said elongate glass tube in axial aligned relation within said first and second interior passages, mounting and sealing means closing the outlet end of said second interior passage, said last named means supporting said capillary chromatograph column so that the inlet end thereof is positioned within said second interior passage, glass baffle means supported within said second interior passage adjacent an outlet end of said elongate glass tube, said glass baffle means including an outer forwardly directed substantially cylindrical cup means and an inner rearwardly directed cup means, said rearwardly directed cup means surrounding an outlet end of said glass tube so as to effect mixing and reversal of direction of gases discharged by said elongate glass tube, said outer forwardly directed cup means surrounding said inner cup means so as to effect a mixing and reversal of gases discharged from said inner cup means, said outer cup means including a substantially cylindrical portion concentrically surrounding the inlet end of said capillary chromatograph column, and means for controllably withdrawing excess amounts of intermixed carrier gas and sample from said second interior passage, whereby sample introduced through said sample port is picked up by carrier gas adjacent the small instrument opening of said glass injector cap, intermixed with the same within said elongate glass baffle means and introduced directly as a linear aliquot to the inlet end of said capillary chromatograph with contact being had only with the inner surfaces of the injector cap, elongate tube and baffle means.

Claim 34

An inlet splitter as in claim 28 wherein said elongate glass tube and said glass baffle means are integrally constructed to insure an inert path of travel of said sample from said sample port to said capillary chromatograph column.

Claim 35

An inlet splitter as in claim 28 wherein said sample port and said respective sealing and mounting means are demountable to permit removal and cleaning of said glass injector cap, elongate glass tube and glass baffle means.

Claim 36

An inlet splitter as in claim 28 wherein said means for controllably withdrawing excess amounts of intermixed carrier gas and sample comprises a valved outlet port communicating through said elongate body with said second interior passage.

Claim 37

An inlet splitter as in claim 28 wherein said elongate glass tube is partially filled with an inert subdivided glass bead packing, said glass bead packing filling a zone within said elongate glass tube extending from a point within said first interior passage to a point within said second interior passage.

Claim 38

In a linear fractionation method for providing substantially pure sample aliquots for capillary gas chromatography, the steps of preheating a stream of carrier gas, introducing said stream of carrier gas to an inner inert core passage, heating said inner inert core passage to maintain a desired elevated temperature of said carrier gas, introducing an analysis sample to said stream of carrier gas within said inner inert core passage to flow with said stream of carrier gas through said core passage, said carrier gas serving to vaporize said sample and thereby form a mixed gaseous stream containing vaporized sample and carrier gas, introducing said mixed gaseous stream to an inert tortuous pathway wherein the direction of flow of said mixed gaseous stream is reversed in such fashion as to obtain a substantially complete turbulent mixing of said vaporized sample and carrier gases, and directing a predetermined volume of hot intermixed sample and carrier gases to the inlet of a capillary gas chromatograph to thereby cause separation of a desired aliquot of the same for capillary chromatographic analysis, the vaporization and intermixing of said sample and the separation of said desired aliquot of intermixed sample and carrier gases taking place wholly within the inert nonreactive environment of said inner inert core passages and said inert tortuous pathway.

Claim 39

In a linear fractionation method for providing substantially pure sample aliquots for capillary gas chromatography, the steps of preheating a stream of carrier gas, introducing said stream of carrier gas to an inner inert core passage, heating said inner inert core passage to maintain a desired elevated temperature of said carrier gas, introducing an analysis sample to said stream of carrier gas within said inner inert core passage to flow with said stream of carrier gas through said core passage, said carrier gas serving to vaporize said sample and thereby form a mixed gaseous stream containing vaporized sample and carrier gas, introducing said mixed gaseous stream to an inert tortuous pathway wherein the direction of flow of said mixed gaseous stream is reversed in such fashion as to obtain a substantially complete turbulent mixing of said vaporized sample and carrier gases, and directing a predetermined volume of hot intermixed sample and carrier gases to the inlet of a capillary gas chromatograph to thereby cause separation of a desired aliquot of the same for capillary chromatographic analysis, the vaporization and intermixing of said sample and the separation of said desired aliquot of intermixed sample and carrier gases taking place wholly within the inert nonreactive environment of said inner inert core passages and said inert tortuous pathway.

Claim 40

A method as in claim 33 wherein enhanced vaporization and intermixing of said sample gas within said carrier gas is obtained in the presence of an inert finely divided inert filler within said inner inert core passage.

Claim 41

A method as in claim 33 wherein the rate of flow of intermixed sample and carrier gases passing into and through said capillary gas chromatograph is within the range from 0.5 to 10 milliliters per minute whereas the rate of flow of said stream of carrier gas is within the range from 6 to 2000 milliliters per minute.

Claim 42

A method as in claim 35 wherein the rate of flow of said stream of intermixed sample and carrier gases within said capillary gas chromatograph is sufficient to attain an optimum average linear flow velocity of the order of 13 to 25 centimeters per second within the capillary column of said gas chromatograph.

Claim 43

A method as in claim 35 wherein the rate of flow of such stream of carrier gas is above about 70 milliliters per minute.

Claim 44

A method as in claim 33 wherein the analysis sample introduced to the chromatograph column is of the order of 0.01 microliters.

Claim 45

In a linear fractionation method for providing substantially pure sample aliquots for capillary gas chromatography, the steps of preheating a stream of carrier gas, introducing said stream of carrier gas to an outer inert annular passage, reversing the direction of said stream of carrier gas to pass inwardly of said outer passage through an inner inert core passage, heating said outer and inner passages to maintain a desired elevated temperature of said carrier gas, introducing an analysis sample to said stream of carrier gas at the point of reversal of direction of said stream so as to flow with said stream of carrier gas through said core passage, said carrier gas serving to vaporize said sample and thereby form a mixed gaseous stream containing vaporized sample and carrier gas, introducing said mixed gaseous stream to an inert tortuous pathway wherein the direction of flow of said mixed gaseous stream is reversed a sufficient number of times to obtain a substantially complete turbulent mixing of said vaporized sample and carrier gases, and directing a predetermined volume of hot intermixed sample and carrier gases to the inlet of a capillary gas chromatograph to thereby cause separation of a desired aliquot of the same for capillary chromatographic analysis, the vaporization and intermixing of said sample and the separation of said desired aliquot of intermixed sample and carrier gases taking place wholly within the inert nonreactive environment of said annular and core passages and said tortuous pathway.

Claim 46

In a linear fractionation method for providing substantially pure sample aliquots for capillary gas chromatography, the steps of preheating a stream of carrier gas, introducing said stream of carrier gas to an outer inert annular passage, reversing the direction of said stream of carrier gas to pass inwardly of said outer passage through an inner inert core passage, heating said outer and inner passages to maintain a desired elevated temperature of said carrier gas, introducing an analysis sample to said stream of carrier gas at the point of reversal of direction of said stream so as to flow with said stream of carrier gas through said core passage, said carrier gas serving to vaporize said sample and thereby form a mixed gaseous stream containing vaporized sample and carrier gas, introducing said mixed gaseous stream to an inert tortuous pathway wherein the direction of flow of said mixed gaseous stream is reversed a sufficient number of times to obtain a substantially complete turbulent mixing of said vaporized sample and carrier gases, and directing a predetermined volume of hot intermixed sample and carrier gases to the inlet of a capillary gas chromatograph to thereby cause separation of a desired aliquot of the same for capillary chromatographic analysis, the vaporization and intermixing of said sample and the separation of said desired aliquot of intermixed sample and carrier gases taking place wholly within the inert nonreactive environment of said annular and core passages and said tortuous pathway.

Claim 47

A method as in claim 39 wherein the inert nonreactive environment of said annular and core passages is maintained by the steps of periodically cleaning exposed surfaces of the same with solvent and thereafter subjecting said exposed surface to the action of a silylanizing reagent.