Shimadzu GC-2014 Instruction Manual

153
13.1
13.13.
GC-2014
13 Detector
13.1Hydrogen Flame Ionization Detector (FID)
13.1.1 Principle of FID operation
In the hydrogen flame ionization detector (FID), hydrogen gas is mixed with the column
outlet gas at a certain ratio as shown in Fig. 13.1.1.The gas mixture combusts in the air
atmosphere. An electrode exists at each end of the FID jet, and DC voltage is applied
between the electrodes.
If only pure carrier gas (nitrogen, helium or argon) and hydrogen gas are mixed, little current
is produced between the electrodes. When an organic compound is mixed with the carrier
gas, current is produced proportionally to the amount of organic compound present.
This is because ions (mainly carbon ions) are generated when an organic compound
combusts within the hydrogen flame, and the generated ions are captured by the collector.
For isomers, the ion quantity generated is almost proportional to the number of carbons
contained in the compound. However, carbon atoms in a “C=O” form do not create a signal.
The presence o halogens in the compound decreases sensitivity.
Because the ion current obtained by the FID is very low, it is amplified into a proper voltage,
then output to a Chromatopac or personal computer.
Fig. 13.1.1

Shimadzu GC-2014 Specifications

General

Type	Gas Chromatograph
Display	LCD
Maximum Heating Rate	120°C/min
Data Acquisition	Digital
Maximum Number of Detectors	4
Weight	Approx. 45 kg
Carrier Gas	Helium, Nitrogen, Hydrogen
Detector Options	FID, TCD, ECD, FPD
Injection Port	Split/Splitless, On-column
Gas Control	Electronic Flow Control (EFC)
Temperature Programming Rate	0.1 to 120 °C/min
Power Requirements	230 V AC, 50/60 Hz
Detector Temperature Range	Up to 400°C (depending on detector type)