【分享】气相质谱连用仪的英文(基本工作原理）每日一贴！

Programmed Temperature Injectors: The programmed temperature injector is held near the boiling point of the solvent; after injection of the sample,it is temperature programmed rapidly until it reaches the desired maximum temperature, which is normally higher than that of an isothermal(constant temperature)injector.As the sample components vaporize ,they are transferred onto the head of the gc column.This technique is a variation of on-column injection ,but reduced the peak broadening frequently seen with on-column infections.

concentration decvices for Sample injection:Several concentrationg devices for organic chemical analyses are commercially available. These devices interface with the inlet system of the gas chromatograph and concentrate organics onto adsorbents such as charcoal an /or porous polymers.The sampleis thermally desorbed onto the head of a gc column by reverse fluhsing with the carrier gas. Concentration devices are also used for analyzing off-gases from such materials as polymers. Often, a simple cool stage is sufficient to trap volatiles that are subsequently desorbed by rapidly increasing the temperature of the trapping device.

GC Detectors:
Flame Ionization Detector: The anallyte in the effluent enters the flame ionization detector(FID) and passes through a hydrogen/air flame. ions and electrodes in the detector by decreasing the gap resistance .By amplifying this current flow a signal is produced. Flame.

Thermal Conductivity detector: In the thermal conductivity detector(TCD). the tempeature of a hot filament changes when the analyte dilutes the carrier gas. With a constant flow of helium carrier gas,ghe filament temperature will remain constant,but as compounds with different thermal conductivities elute, the different gas compositions cause heat tobe conducte d away from the filament at different rates,which in turn causes a change in the filament temperature and electrical resistance , The TCD is truly a universal detector and cna detect water ,air, hydrogen, carbon monoxide, nitrogen,sulfur diocide,and many other compounds . For most organic molecules ,the sensitivity of the TCD detector is low compared to that of the fid,but for the compounds for which the FID produces little or no signal ,the TCD detector is a good alternative.

Thermionic speciific detector: The thermionic specific detector (TSD)is similar to the FID with the addition of a small alkali salt bead, such as rubidium,which is placed on the burner jet.Nitrogen and phosphorus compounds increase the current in the plasma of vaporrized metal ions.The detector can be optimized for either nitrogen-containing compounds or phosphorus -containing compounds by careflly controlling of the bead temperature and hydrogen and air flow rates .The detector can be tuned using azobenzene for nitrogen and parathinon for phosphorus.

Flame photometric detector:with the flame photometric dectector ,sa with the FID, the samlple effluent is burned in a hydrogen/air flame. By using optical filters to select wavelengths specific to sulfur and phosphorus and a photomultiplier tube ,sulfur or phosphorus compounds can be selectively detected

都是基本工作原理，有学英语！！！

没人支持,自己来顶!!!!

学习,学习~~~

哈哈,我帮你顶.
不过请问一下,走空针对仪器有什么好处?
是不是每天都走一个空针话,对仪器有好处?
哪位能回答一下,我在这儿谢过了.

应助达人

走空针可以看看柱子干不干净，需不需要老化。

我帮忙顶下

能不能给个完整的啊