| 摘要 |
An injector for use with a capillary supercritical fluid chromatography (SFC) apparatus includes an operable four-port switching valve having a body portion and a rotor rotatably mounted within the body portion. The rotor has a hole therethrough which will selectively register with pairs of aligned ports. Thus, the rotor is rotatable between a loading position, wherein a first and third port are in communication, and a chromatographic position, wherein a second and fourth port are in communication. A first tubular member extends from the third port and is connected to a retention gap, which is in turn connected to an end of a capillary SFC column. A bypass tube connects the fourth port to the first tubular member. The loading position of the rotor and the first tubular member form a straight pathway to permit a needle to be inserted therethrough into the retention gap to inject a sample. A method is also disclosed whereby said injector permits the venting of a sample solvent from the injector by cycling the rotor, between the chromatographic and loading positions for predetermined time intervals.
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