J&w Scientific Incorporated

Norman W Wohlers

Rand G Jenkins

Walter G Jennings

Robert H Wohleb

Precision bore fused silica tubing with tapered section

An apparatus and method for injecting samples into capillary-type gas chromatographic columns allows a portion of the column to be withdrawn from the chromatograph oven prior to injection. The sample is injected into the withdrawn portion of the column which is then inserted back into the oven to initiate volatilization. The apparatus includes a syringe holder which is attached to the inlet end of the column and a collapsible support mechanism for extending the syringe holder away from the chromatograph oven. The sample is injected into the column while the support is extended away from the oven. After the injection is completed, the support is collapsed causing the portion of the column carrying the sample to be abruptly introduced into the oven.

On-column injector

Fused silica syringe needle

Chromatographic on-column injector

Cage for a chromatography fused-silica capillary column

The numerous advantages of a Soxhlet apparatus are combined with the nice pressure and temperature controls afforded by a pressure vessel to enlarge the scope and efficacy of both pieces of equipment. A judicious selection of solvent, such as CO.sub.2, provides a solvent-free extract which is ideal for gas chromatographic studies and can advantageously be used in an ever-widening spectrum of analyses including research, food and flavor, pheremone analysis and essence extraction. The extraction of oil from coal and oil shale, in comminuted form, is also facilitated by the use of the apparatus operated under reflux conditions, controlled pressure-temperature relations and appropriate choice of extractant.

High pressure Soxhlet extractor

High pressure soxhlet extractor

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Davis, CA, United States of America

Norman W Wohlers