| 摘要 |
<p>An improved method and apparatus are described for carrying out SPME onto the inner surface of a syringe needle at least partially coated with a stationary phase followed by desorption of analytes from a sample into a gas chromatograph injector for analysis. The SPME apparatus comprises a syringe having a syringe barrel and a plunger slidable within one end of the barrel, a hollow needle extending from the other end of the barrel and having its inner surface coated with the stationary phase, and fluid communication means for transferring a fluid into contact with the coated inner surface of said hollow needle. During the analysis phase, a carrier gas is transferred into contact with the coated inner surface. A valve means can be used to switch the flow of sample from a container containing the sample during the microextraction phase to the carrier gas during the analysis phase. In a preferred embodiment of the present invention, the carrier gas is preheated before passing into the syringe during the analysis phase.</p> |
