초록 ▼

Apparatus and method for injection of samples directly onto a column in a gas chromatograph with injection occurring in a temperature controlled zone outside the oven. The apparatus combines a guide means and valve assembly in alignment with an injection and thermal transfer assembly. In the guide m

Apparatus and method for injection of samples directly onto a column in a gas chromatograph with injection occurring in a temperature controlled zone outside the oven. The apparatus combines a guide means and valve assembly in alignment with an injection and thermal transfer assembly. In the guide means and valve assembly a radial seal engages the injection means to seal the injection volume, thereby eliminating back flash. In the injection and thermal transfer assembly the capillary column is centered and held in fixed position within a duct means. Means is provided to lower the temperature of the capillary column to a temperature below the vaporization temperature of the liquid sample prior to injection. After injection, means is further provided to raise the temperature of the capillary column to a temperature above the volatilization temperature of the liquid sample to vaporize it and pass it into the capillary column. The method of on-column injection of the present invention comprises inserting an injection means through a radial seal means to a point just above a valve, opening the valve, further inserting the injection means through the valve and into the end of that portion of the capillary column within the thermal transfer assembly and outside the oven of the gas chromatograph, injecting a liquid sample into the end of the capillary column while maintaining the column at temperature below the vaporization temperature of said liquid sample, withdrawing the injection means from the capillary column and the valve means, closing the valve means, withdrawing the injection means through the injector duct and the radial seal means, and heating said column within said temperature controlled zone to volatilize said sample and pass it into said column.

대표청구항 ▼

An injector for introduction of a liquid sample directly into a capillary gas chromatographic column, the point of injection within said column being enclosed within a temperature controlled zone, comprising: means for heating said column within said temperature controlled zone to at least the vapor

An injector for introduction of a liquid sample directly into a capillary gas chromatographic column, the point of injection within said column being enclosed within a temperature controlled zone, comprising: means for heating said column within said temperature controlled zone to at least the vaporization temperature of said sample during a portion of the injection cycle, said temperature controlled zone being located outside the oven of said gas chromatograph; means for maintaining said column within said temperature controlled zone at a temperature below the vaporization temperature of said liquid sample while said liquid sample is introduced through the end of said column directly to said point of injection; duct means for holding said end of said gas capillary column, said duct means serving to fix and stabilize said column to thereby permit liquid samples to be introduced directly into said column at said point of injection; and sealing means within said duct means for enabling introduction of said liquid sample without fluctuation in the carrier gas flow.