Detectors 091
Detectors 091 : Particle Detectors: (4.4) Chromatography Detector: A chromatography detector is a device used in gas chromatography (GC) or liquid chromatography (LC) to visualize components of the mixture being eluted off the chromatography column. There are two general types of detectors: destructive and non-destructive. The destructive detectors perform continuous transformation of the column effluent (burning, evaporation or mixing with reagents) with subsequent measurement of some physical property of the resulting material (plasma, aerosol or reaction mixture). The non-destructive detectors are directly measuring some property of the column effluent (for example UV absorption) and thus affords for the further analyte recovery. Destructive detectors: (a) Flame ionization detector. The column effluent is injected into hydrogen flame and the flame conductivity is measured. Only used in GC. (b) Aerosol-based detector[NQAD]. The column effluent is nebulized, the mobile phase evaporated, a water shell condensed on it and then it is detected. Very sensitive detection for reverse phase applications. (c) Flame photometric detector, (FPD). Column eluate is burned in hydrogen flame. The light of the flame is filtered through an optical filter. Allows the detection of sulfur and phosphorus. (d) Atomic-emission detector (AED). The column effluent is injected into plasma and the plasma spectrum is recorded. This detector allows for immediate determination of the elements present in the analyte. (e) MS detector. The column effluent is continuously injected into mass spectrometer. This detector allows for immediate determination of the molecular weight of analyte and/or fragmentation pattern thus providing a significant amount of information about analyte. (f) Nitrogen Phosphorus Detector, used only in GC
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