Tag Archives: gas chromatography
The figure below provides a block diagram of a typical gas chromatography-mass spectrometer (GC–MS) instrument. As illustrated here, a three component mixture enters the GC. When component A elutes from the column, it enters the MS ion source and ionizes to form … Continue reading
The schematic diagram below shows a flame ionization detector for gas chromatography. The eluent from the column mixes with H2 and is burned in the presence of excess air. Combustion of organic analytes produces a flame containing electrons and organic … Continue reading
One of the earliest gas chromatography detectors takes advantage of the mobile phase’s thermal conductivity. As the mobile phase exits the column it passes over a tungsten-rhenium wire filament (see figure below). The filament’s electrical resistance depends on its temperature, … Continue reading
Shown here is a schematic diagram of a heated GC injector port for use with packed columns. The needle from the syringe pierces a rubber septum and enters into the top of the column, which is located within a heater … Continue reading
Shown here is an example of a syringe for injecting samples into a gas chromatograph. This syringe has a maximum capacity of 10 μL with graduations every 0.1 μL.
Solid-phase microextraction (SPME) is an attractive method for isolating an analyte prior to injecting it into a gas chromatograph. In one approach, which is illustrated here, a fused-silica fiber is placed inside a syringe needle. The fiber, which is coated with … Continue reading