Shimadzu 2014 Gas Chromatograph
The Shimadzu GC-2014 gas chromatograph is equipped with FID (with methanizer), ECD (Ni63), and TCD detectors, and is set up for analysis of N2O, CH4, CO2, CO, O2, and N2. The detection/quantitation limits of the instrument are as follows:
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N20: 50ppb to 100ppm by ECD
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CO2, CO: 1ppm to 1% by methanizer and FID, 10ppm to 10% by TCD
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CH4: 0.1ppm to 1% by FID
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O2, N2: 100ppm to 20% by TCD
The Shimadzu 2014 is supported by GCSolutions software running on a Dell computer.
B. Theory of Gas Chromatography
In gas chromatography a gas sample is swept by a carrier gas through a stainless steel tube called a column that is packed with a material (Haysep Q or N) that the different gases in the sample have a different affinity for. For example, consider a sample of air containing 78% N2, 20.95% 02, 0.95% Ar, 0.035% CO2, and 1.8ppm CH4. If injected into a carrier gas and swept through a column of Haysep N, then the N2/O2/Ar goes through the column first closely followed by CH4 and then CO2. Haysep N has very little affinity for N2/O2/Ar, some affinity for CH4 and a great affinity for CO2. By varying column packing it is possible to separate different mixtures of gases.
C. Theory of Operation (ECD, FID, TCD)
The instrument utilizes three valves (two 10-ports, and a four port) in order to separate a single sample injection into three separate slugs which are routed to the TCD, FID, and ECD, respectively. actually two gas chromatograph systems sharing the main oven: an electron capture detector (ECD) for N20 analysis and a flame ionization detector (FID) for CH4 and CO2 analysis.
For further information regarding operation of this instrument, please refer to the Users page.