求高人帮忙翻译一下,非常感谢
Injectors-After dissolution in mobile phaseor other suitable solution, compounds to be chromatographed are injected intothe mobile phase, either manually by syringe or loop injectors, orautomatically by autosamplers. The latter consist of a carousel or rack to holdsample vials with tops that have a pierceable septum or stopper and aninjection device to transfer sample from the vials to a calibrated, fixed-volumeloop from which it is loaded into the chromatograph. Some auto-samplers can beprogrammed to control sample volume, the number of injections and loop rinsecycles, the interval between injections, and other operating variables.
A syringe can be used for manual injectionof samples through a septum when column head pressures are less than 70atmospheres（about 1000psi）. At higher pressure an injection valve is essential.Some valve systems incorporate a calibrated loop thatis filled with test solution for transfer to the column in the mobile phase. Inother systems, test solution is transferred to a cavity by syringe and thenswitched into the mobile phase.