Gas Chromatography (GC)

Part 1: Characterizations
Part 2: Data Analysis

Part 3: Maintenances

Part 1: Characterization

(1) Ramp up the equipment to working conditions . You may choose either (a) CO2 Experiment (Standard) or (b) CO2 Experiment (Trace)

(2) Key in the characterization details "Sample Name" and "Result Name". Change the “Proc. method” accordingly with the “Acq. method”, i.e., Method 1 or Method 2.

(3) Ensure the Status bar is green, which means it is idle for injection. Click the Green Button “Run” on the panel. Run Queue will show “Acquiring”. The status bar will show “Waiting for injection…”


(4) Use Syringe to withdraw your gas product from the outlet of CO2 flow cell. You should flush the syringe with your product gases for 5 times before slowly extracting your gas products for 1 mL. Inject the gas into the GC hardware and click the run button on the GC hardware panel.

Remarks

Method 1: “CO2 Experiment (Standard). amx”

Method 1 is programmed to quantify a series of by-products, specifically, the CO with a HIGH concentration ( > 1000 ppm).
TCD (Thermal Conductivity Detector) is a universal detector for organic gases (C-H or C=H bonds) and inorganic gases (N2, SO2, CO2, CO) because these gases have different thermal conductivity from the carrier gas (e.g., Hydrogen or Helium). However, the TCD cannot effectively quantify low-concentration CO due to the limit of sensitivity.



Method 2: “CO2 Experiment (Trace CO). amx”
Method 2 is programmed to quantify a series of by-products, specifically, the CO with a LOW concentration ( < 1000 ppm) .The trace amount of CO is converted into CH4 using the jetcanizer (Ni catalyst) and measured by FID (flame ionization detector). The FID can quantify the carbon-hydrogen bond effectively by flaming it. The amount of CO can be quantified via a CO and CH4 correlation. Avoid using Method 2 for high-concentration CO experiments because the Ni catalyst in the jetcanizer will die soon.

".amx" = acquisiotn method


Part 2: Data Analysis

(1) Control panel >> Select your Project "Ling Ning" under “Projects” >> “Start Data Analysis”. Under “Data Selection” select your data folder. Go to the “Injection List”, and select the data you want to analyze.

(2) Pin the results you want to do quantitative analysis, they will be overlapped on the chromatograms. If the data does not present, click “Reprocess All” to update them. You should be able to see the quantitative results (ppm) in the “Injection Results”.


There is an in-built calibration reference for qualitative and quantitative analyses of the following gases:

  • H2 (hydrogen)

  • CO (carbon monoxide)

  • CH4 (methane)

  • CH2=CH2 (ethylene)

  • CH3-CH3 (ethane)

  • CO2 (carbon dioxide)

Generally speaking, the peaks sequences based on the retention times on the chromatograms are as follows:

H2---O2---N2---CO---CH4---CO2---CH2=CH2---CH3CH3


Part 3: Maintenances: Restart the PC & GC hardware

In the case that the software and hardware have problems, e.g., hanging for a long time or cannot communicate with each other, you may need to consider restarting both the PC and GC hardware.


Load the “Cooling Method” and wait for the equipment cool down to 40oC. When the temperature reaches 40oC, turn off the GC hardware button and the PC.


Note: Directly turn off the GC hardware at 220oC (which also turns off the gas supply) to make the Ni catalyst of jetcanizer stands a chance to react with the air and be oxidized.