Gas Chromatography and GC/Mass Spectrometry

GC:
Click below for a movie on how to use the Gas Chromatograph. The movie is best viewed with sound.

GC/MS:
Although students will not not use the GC/MS machine, they will frequently have to use GC/MS data to analyze chemical compounds.

To retrieve GC/MS data from SCI 230:
Room 230 should be open 7 days a week/24 hours a day.
Use any of the computers in the front row. Look for these directions…they should be next to the computers that have the appropriate software for your GC/MS analysis.

Log in to the Windows desktop using your Windows Domain Name and Password.

Use the left mouse button unless otherwise instructed.

1. Double-click on the desktop icon with the name, "Data on 'Hpgcms5890'(z)".

2. Type in guest for the User name and password. (You have now mapped the GC/MS computer to your computer!)

3. In the START menu, go to All Programs and find GC_MS Instrument #1 [OR…find the GC_MS Instrument #1 Icon on the Desktop.] Open the Data Analysis #1 program.

4. Under File, select Load....


5. In the Drives: window, select z: Hpgcms5890\DATA.

6. Open the 211(semester & year) folder by double-clicking on it.

7. Open the folder for your lab day and then, your experiment, e.g. Fri & Dehyd.

8. Select (Don't open) your own data folder, e.g. wendy.d and click OK. This will bring your GC to the screen.

9. From the menu bar, select Chromatogram and then select Percent Report.
[Copy and paste your percent report into your e-lab by clicking on the Screen box and deselecting the Printer box.  Then, select OK.  Highlight the area of the percent report that you wish to copy and under Edit, select Copy.  Open the document you want to paste your percent report in and under Edit, select Paste.]

10. To obtain a mass spectrum of any compound in your GC, put the cursor directly over the middle of the GC peak and double click with the right mouse button. [I recommend that you follow the instructions below for enlarging each GC peak before obtaining it’s mass spectrum.]

11. You will need to remove the masses in your mass spectrum that come from the compounds which make up the baseline in your GC.
To do this, generate the mass spectrum for the GC peak you are interested in. Then, generate the mass spectrum of the baseline to the left or right of the GC peak. Make sure the area you select is completely flat and isn't part of any GC peak. Under Spectrum, in the menu bar at the top of the screen, highlight Subtract. This will generate the mass spectrum for your compound only. It will remove any masses in your spectrum created by the baseline compounds, such as the solvent that you dissolved your sample in.

12.  Only print or copy the peaks and mass spectra that are of interest to you.  To print: go to File and select Print.  To copy either your GC or MS for your e-lab: find Options in the menu bar and select Copy Window….  In the Input window, type 2 for your GC on the screen or type 1 for your MS on the screen.  Open the document you want to paste your GC or MS in and under Edit, select Paste.
For the Dehydration lab, you should print out 3 mass spectra in all.  2 of the 3 spectra will be of your 2 expected products. The third mass spectrum should come from a peak that is from an unexpected product and not from unreacted starting material.

13. Once the printing or copying are finished, go to File and select Exit.

14. Remember to log off of your computer.