INSTRUMENTAL ANALYSIS OF PROCESS PRODUCTS, CHFEN 5503
Spring Semester, 2004
Introduction to Gas and Liquid Chromatography
March 24,25, 2004 (same early and late team sequence as the first FTIR lab)
March 31 and April 1,7,8, 2004 (2 weeks, full time or as needed)
OBJECTIVES FOR THIS SET OF CHROMATOGRAPHY LABS:
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Learn to make manual injections of gases and liquids for GC analysis
Learn to control the GC data output in strip chart recorder and computer format
Learn to troubleshoot GC analysis problems
Learn to safely startup and shut down a GC with an FID detector
Gain experience using packed and capillary GC columns, temperature programs, TCD and
FID detectors
Gain experience establishing optimum GC operating conditions
Perform a quantitative GC analysis of unknown liquids and/or gases
Establish a method for determining retention times and response factors for GC and HPLC
Learn to make manual injections of liquids for HPLC analysis
Perform a quantitative HPLC analysis for sugars in a juice drink
If possible, compare the response of two different Auniversal@ HPLC detectors
ASSIGNMENTS AND PROBLEMS:
12.
March 24/25: Two teams with 3 and/or 4 members meet for basic instruction and practice gas
and liquid analysis using GC=s and the HPLC. Two or more GC instruments will be used to
perform a gas and liquid analysis. Data will be taken by recorder and by computer. Different GC
columns can be evaluated for separation of gases. Only one HPLC column will be used for sugar
analysis.
2.
Using each of the gas analysis GC=s, each student must individually produce your personal
best chromatograms of:
a. hydrocarbon standards provided
b. an Aunknown@ gas mixture
3.
Try to identify all of the peaks on the GC gas chromatograms above. In your report estimate the
relative volume (or weight) of the components in the unknown gas based on peak area only.
When you report this, be sure to explain your methods and rational.
4.
Liquid analysis on the GOW-MAC GC is for practice this week but you may want to record
retention times, areas, and amount injected for future reference.
5.
For the HPLC develop a table of sugar knowns, their retention times, and their peak areas per
unit mass of sugar injected. Develop a brief written team plan for the analysis of sugars in a
juice drink (see #11 below). Sugar standards will be provided.
GC lab, page 2
6.
March 31/April 1: Receive instruction on the use of the HP GC with FID for liquids or gas
analysis. Complete any gas analysis above not completed last week.
7.
As a team, use the available GC=s and the installed columns to determine the retention times and
peak areas (for equal volumes injected) of as many liquids below as time allows: Teams will get
1.0 hours for their first use of each of the liquid analysis GC=s.
acetone
methanol
2-propanol
3-pentanone
ethyl acetate
carbon tetrachloride
2-butanone
ethanol
8.
As a team, develop a brief written experimental plan (see #11 below) for the quantitative GC
analysis of an unknown liquid (suspected of containing one or more of the compounds in 5
above) using the apparatus and data determined in 7 above. Be sure to address which separations
appear to be impractical with the installed columns.
9.
Chromperfect software should be used for your GC liquid analysis.
10.
Using the HPLC and the sugar column, as a team, determine the concentration of the individual
sugars in three different juice or soda drinks. Report your results in mg/ml and units consistent
with the can or bottle label (e.g. g/can). You may have to dilute the juice, but you should report
both diluted and undiluted results.
11.
The team written experimental plans are due on or before April 7/8 and should be submitted as a
separate document to J.V. Fletcher. Since they are brief, they may be done in lab and will be
read and OK=d as received. They will not be graded.
12.
You will be given an unknown liquid to analyze using your plan (#8 above) after its review and
approval. The liquid can be analyzed as time permits over the remaining weeks of lab. A brief
Memo report on the quantitative contents of your GC liquid unknown is due by the last Friday of
the regular semester (April 30, 2004).
13.
Complete 1-9 by April 7/8. A Team Memo Report is due Tuesday, April 20, 2004, with at least
the original chromatograms and the revised (i.e. as used) GC and HPLC team plans attached.
Some suggestions for the gas and liquid analysis using the GOW-MAC GC=s (also see sample
chromatograms in the lab):
a. Do the gas analysis at less than 100C and inject 0.5ml or less. Keep attenuation low.
b. Run the chart recorder as slow as possible to keep peaks from being too broad. Too slow will
not give a readable separation, however.
c. When you do liquids on the GOW-MAC 580, use column B. The oven should be at 40-80C
or less and He flow at about 25 ml/min. Limit the filament amps to 200 mA.
d. Inject the same volume for each known liquid (Try 0.2 microliters at an attenuation of 1 if the
computer is used on the GOW-MAC 580)
e. If you have time you should prepare a synthetic mixture of two liquids from #7 above and try a
separation.
f. Best conditions for the HP GC=s will be available at the instrument.