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Gas chromatography methods and apparatus

  • US 4,923,486 A
  • Filed: 12/22/1988
  • Issued: 05/08/1990
  • Est. Priority Date: 12/22/1988
  • Status: Expired due to Term
First Claim
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1. In a 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, the improvement 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 selected locations of said column(b) providing a curvilinearly shaped negative temperature gradient along said column by said temperature control means, with the temperature at the elution port of said column being maintained lower than the temperature at the inlet port thereof at all times except for the end of said analysis so that the sample will continuously be subjected to a lower temperature as it travels in a downstream direction along said column, said column and said temperature control means being capable of transferring changes of at least about 0.5°

  • C. per second from said temperature control means to said column and(c) raising the temperature of the column at said elution port at the end of said analysis so that said sample will elute from the column.

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