US5028243A — Gas chromatography methods and apparatus

Claim 1

Independent Claim 91 words

Method of performing gas chromatographic analysis wherein a sample is admitted to a chromatographic column and caused to travel in a direction from upstream to downstream from an inlet port of said column to an elution port, comprising the steps of (a) providing temperature control means in thermal transfer relation with said column, said temperature control means being adapted to heat or cool said column to a desired temperature, and (b) transferring desired temperature changes of at least about 0.5° C. per second from said temperature control means to said column.

Claim 2

Dependent Claim 91 words

Method of performing gas chromatographic analysis wherein a sample is admitted to a chromatographic column and caused to travel in a direction from upstream to downstream from an inlet port of said column to an elution port, comprising the steps of (a) providing temperature control means in thermal transfer relation with said column, said temperature control means being adapted to heat or cool said column to a desired temperature, and (b) transferring desired temperature changes of at least about 0.5° C. per second from said temperature control means to said column.

Claim 3

Dependent Claim 26 words

Method as recited in claim 1 further comprising transferring changes of at least about 30° C. per second from said temperature control means to said column.

Claim 4

Dependent Claim 20 words

Method as recited in claim 1 wherein said step (a) comprises contacting said column with a flow of cooling fluid.

Claim 5

Dependent Claim 19 words

Method as recited in claim 3 wherein the temperature of said cooling fluid is less than about -100° C.

Claim 6

Dependent Claim 31 words

Method as recited in claim 3 comprising providing flow of said cooling fluid along and in heat transfer relation with said column from a downstream to upstream portion of said column.

Claim 7

Dependent Claim 15 words

Method as recited in claim 1 further comprising regulating the pressure of said cooling fluid.

Claim 8

Dependent Claim 15 words

Method as recited in claim 6 further comprising programming variations in said pressure over time.

Claim 9

Dependent Claim 21 words

Method as recited in claim 1 wherein said step (a) comprises contacting said column with a flow of ambient temperature fluid.

Claim 10

Dependent Claim 12 words

Method as recited in claim 8 wherein said fluid is nitrogen gas.

Claim 11

Dependent Claim 32 words

Method as recited in claim 8 comprising providing flow of said ambient temperature fluid along and in heat transfer contact with said column from an upstream to downstream portion of said column.

Claim 12

Dependent Claim 16 words

Method as recited in claim 10 further comprising regulating the pressure of said ambient temperature fluid.

Claim 13

Dependent Claim 15 words

Method as recited in claim 11 further comprising programming variations in said pressure over time.

Claim 14

Dependent Claim 24 words

Method as recited in claim 1 wherein said step (a) comprises providing an electrical resistance heating means in heat exchange relationship with said column.

Claim 15

Dependent Claim 22 words

Method as recited in claim 13 further comprising surrounding both said resistance heating means and said column with an insulating sheath assembly.

Claim 16

Dependent Claim 23 words

Method as recited in claim 14 wherein said sheath assembly comprises a quartz conduit surrounding and coaxially disposed with respect to said column.

Claim 17

Dependent Claim 24 words

Method as recited in claim 15 wherein said sheath assembly further comprises a sleeve surrounding and coaxially disposed with respect to said quartz conduit.

Claim 18

Dependent Claim 19 words

Method as recited in claim 14 further comprising varying the temperature imparted by said resistance heating means over time.

Claim 19

Dependent Claim 28 words

Method as recited in claim 14 further comprising admitting a first heat exchange fluid to said sheath assembly to further regulate the heating or cooling of said column.

Claim 20

Dependent Claim 41 words

Method as recited in claim 18 wherein said fluid comprises a cryogenic fluid, said method further comprising causing said fluid to flow in said sheath and along said column in a direction from a downstream to upstream portion of said column.

Claim 21

Dependent Claim 17 words

Method as recited in claim 19 further comprising varying the pressure of said cryogenic fluid over time.

Claim 22

Dependent Claim 42 words

Method as recited in claim 19 further comprising admitting a second heat exchange fluid to said sheath assembly, and causing said second fluid to flow in a direction along said column that is opposite from the flow direction of said first fluid.

Claim 23

Dependent Claim 32 words

Method as recited in claim 21 wherein said first fluid is nitrogen having a temperature of about -100° C. or less and wherein said second fluid is nitrogen having an ambient temperature.

Claim 24

Dependent Claim 92 words

Gas chromatographic apparatus of the type adapted to perform sample separation analysis comprising (a) an open tubular chromatographic column having a sample inlet port located at an upstream portion of said column and a sample elution port at a downstream portion of said column, (b) temperature control means in thermal transfer relation with said column for imparting a desired temperature to said column, said column (a), and temperature control means (b) being capable of transferring changes of at least about 0.5° C. per second from said temperature control means to said column.

Claim 25

Dependent Claim 92 words

Gas chromatographic apparatus of the type adapted to perform sample separation analysis comprising (a) an open tubular chromatographic column having a sample inlet port located at an upstream portion of said column and a sample elution port at a downstream portion of said column, (b) temperature control means in thermal transfer relation with said column for imparting a desired temperature to said column, said column (a), and temperature control means (b) being capable of transferring changes of at least about 0.5° C. per second from said temperature control means to said column.

Claim 26

Dependent Claim 27 words

Apparatus as recited in claim 23 wherein said temperature control means comprises heater means and a temperature and time programmer in operative association with said heater means.

Claim 27

Dependent Claim 49 words

Apparatus as recited in claim 23 further comprising an insulating sheath means surrounding said column and wherein said temperature control means comprises a passage formed within said sheath, a source of a first heat transfer fluid being connected with said passage and in heat transfer relation with said column.

Claim 28

Dependent Claim 25 words

Apparatus as recited in claim 25 further comprising a programmer means for regulating pressure of said first heat transfer fluid being admitted to said passage.

Claim 29

Dependent Claim 29 words

Apparatus as recited in claim 23 further comprising a source of a second heat transfer fluid being connected with said passage and in heat transfer relation with said column.

Claim 30

Dependent Claim 26 words

Apparatus as recited in claim 27 further comprising a second programmer means for regulating pressure of said second heat transfer fluid being admitted to said passage.

Claim 31

Dependent Claim 40 words

Apparatus as recited in claim 23 further comprising an insulating sheath means surrounding said column with a passage formed in said sheath, said temperature control means comprising heater means disposed in said passage in heat exchange relation with said column.

Claim 32

Dependent Claim 31 words

Apparatus as recited in claim 29 further comprising a temperature programmer operatively connected to said heater means for varying the temperature of said heater means over a given period of time.

Claim 33

Dependent Claim 42 words

Apparatus as recited in claim 29 wherein said temperature control means also comprises a source of a first heat transfer fluid connected with said passage and means for regulating the pressure of said first heat transfer fluid being admitted to said passage.

Claim 34

Dependent Claim 41 words

Apparatus as recited in claim 31 wherein said temperature control means comprising a source of a second heat transfer fluid connected with said passage and means for regulating the pressure of said second heat transfer fluid being admitted to said passage.

Claim 35

Dependent Claim 75 words

Gas chromatographic apparatus comprising an open tubular chromatographic column having an upstream sample inlet port and a downstream sample elution port, a heater in thermal transfer relation with respect to said column, fluid regulating means for passing a heat exchange fluid into heat exchange relation with said column, said heater being operatively connected to a time and temperature control programmer and said fluid regulating means being operatively connected to a time and flow rate regulator.

Claim 36

Dependent Claim 75 words

Gas chromatographic apparatus comprising an open tubular chromatographic column having an upstream sample inlet port and a downstream sample elution port, a heater in thermal transfer relation with respect to said column, fluid regulating means for passing a heat exchange fluid into heat exchange relation with said column, said heater being operatively connected to a time and temperature control programmer and said fluid regulating means being operatively connected to a time and flow rate regulator.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1994-07-01	1994-12-31	1995-07-02	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1998-07-01	1998-12-31	1999-07-02	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2002-07-01	2002-12-31	2003-07-02	$7700.00	Window Closed / Lapsed

Gas chromatography methods and apparatus

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