Method and device for vaporization injection of a liquid sample for gas chromatographic analysis
AssigneeCarlo Erba Strumentazione S.p.A.
InventorsGiorgio Sisti, Mario Galli, Sorin Trestianu
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Abstract
This invention relates to a method and a device for vaporization injection of a liquid sample in a gas chromatographic column housed in an oven comprising a direct on column injector suitable for injecting a liquid sample into the initial zone of a capillary column and capable of pneumatically sealing the injection port at the end of injection. Between the injector and the gas chromatographic column itself an uncoated capillary column length is provided in which vaporization of the injected sample occurs using heat from an oven housing said capillary column length, said oven being the same or separate from the oven containing said gas chromatographic column.
Claims10
A device for effecting controlled vaporization injection of a liquid sample for gas chromatographic analysis, comprising:
- a vaporization tube provided with temperature control means for maintaining an injected sample in the liquid state until injection is complete and then effecting controlled heating and vaporization of the sample, said tube being adapted to communicate at its upstream end, through a closable valve, with injection means, and at its downstream end, through sample splitting means, with a chromatographic column containing a stationary liquid phase for gas chromatographic separation of the vaporized sample exiting the vaporization tube;
- injection means communicating through said valve with the upstream end of said vaporization tube, for direct injection of a liquid sample into an initial zone of said tube, and provided with valve means for closing off said injection means following injection of said sample into said tube;
- and
- sample splitting means communicating with the downstream end of said vaporization tube and with the upstream end of said chromatographic column, for splitting said vaporized sample and diverting a portion thereof from said column, said splitting means being provided with valve means for controlling the splitting ratio.
A method for effecting controlled vaporization injection of a liquid sample for gas chromatographic analysis, comprising the steps of:
- injecting a liquid sample into the initial zone of a sample vaporization tube which does not contain stationary liquid phase, the sample being maintained in the liquid phase during substantially the entire injection process;
- heating the vaporization tube to vaporize the sample, and passing a carrier gas therethrough to entrain the vaporized sample;
- and
- diverting a portion of the resultant mixture of vaporized sample and carrier gas by means of a sample splitter, and conducting the remainder to a chromatographic column containing a stationary liquid phase for chromatographic separation, while maintaining a substantially constant splitting ratio, being the ratio of said remainder which is sent to the chromatographic column compared to the total mixture, by controlling the amount of diverted mixture as a function of the temperature of the heated vaporization tube.
Dependencies are inferred from the claim text.