Chem. 231 – 1/28 Lecture
Introduction
Goals of Course
• Discussion of More Practical Aspects of
Separation Science
• Provide Specific Lab Training in Use of
Chromatography Instruments and Simple
Separations (e.g. Extractions)
• Facilitate Semi-Independent Student
Learning
• Improve Communication Skills
Syllabus
Class/Discussion Meeting Times
• Not exactly as in syllabus
• We typically have extended discussions and
instrument demonstrations in the beginning
• We will end discussion “lectures” about half the
way through the semester; Discussions will then
occur for 3rd lab oral presentations
• Some work can be performed outside of class
hours (once first lab is completed) provided
work doesn’t interfere with other classes and
follows department policy
Syllabus
Website + Discussion
• Additional Course Information on
Website
• Discussion Topics
– In past, I covered “practical” topics I
thought were important
– I expect topics to be divided between
general “practical” information and
information specific for the experiments
to be performed
Syllabus
Laboratory Experiments
• Set 1 Labs
– Relatively simple experiments to
demonstrate use of HPLC and GC
– Will need to do both laboratory
experiments
– One will include quantitative work that
will be reported while the other will just
be for competency
Syllabus
Laboratory Experiments
• Set 2 Labs
– Both labs use extraction methods as
would be typical for extraction of
compounds from complicated matrices
– HPLC lab will use solid phase extraction
to trap phenols from an aqueous matrix
– GC lab will use solid phase
microextraction to trap volatile
compounds from gas
Syllabus
Laboratory Experiments
• Set 3 Labs
– The focus of these experiments will be
to derivatize fatty acids and carbonyl
compounds for subsequent analysis by
GC and HPLC
– Students will provide additional samples
of interest
Syllabus
Laboratory Experiments
• Term Project Labs
– These are meant to be more
independent
– Students can isolate an ingredient from
a household product or
– Students can work on a separation using
equipment beyond that used in the first
3 experiments (e.g. use HPLC with
fluorescence detection)
Syllabus
- Notes on Grading
• Homework and Quizzes
– 10% of grade
– In discussion and on discussion materials
• Final Exam
– 15% of grade
– No date set yet because previously given after
discussion lectures end and after set 2 labs begin
– Good dates would be the Monday before or after
Spring Break
Syllabus
- Notes on Grading (2)
• Lab Reports
– 75% of grade
– Will submit 4 formal written reports (one for
each lab + for the term project) (65% of
grade)
– Will submit one ungraded report for the other
set 1 lab (e.g. formal for HPLC and informal
for GC)
– Will give one oral report on your particular
sample in the (Set 3) derivatization lab (10%
of grade)
Lab Safety
• Safety Equipment Required
– Goggles, gloves and lab coats needed
– Must wear long pants and shoes covering feet below
ankle
– Goggles and lab coats should be worn while running
instruments, but gloves only needed when handling
chemicals
– Gloves should not be worn outside of labs (people get
concerned that you are spreading toxic compounds)
– Gloves can both protect your hands from chemicals
(e.g. from dinitrophenylhydrozene) and protect your
samples from your hands (e.g. from fatty acids)
Other Lab Equipment Needed
• Lab Notebook (and pen)
• Lab Instructions (see e.g. Set 1 Lab
Instructions)
• Notes from Discussion
• Memory stick/floppy drive
Discussion Topics
• Practical Aspects of Separation Science
– example: demonstration and discussion of
how SPE cartridges work and are used
• Specific Tools Needed for Our Labs
– example: how to set up file folders to save
data using the Agilent HPLC
Today’s Discussion Topic:
Data Processing
•
•
•
•
How to Set Up Folders
Saving Raw and Processed Data
Excel Processing of Raw Data
External Standard Calibration Using Excel
Today in Lab
• Check in to lockers
Data Processing
How to Set Up Folders
• Whenever possible, use your own folders
• Advantages:
– All your stuff should go there
– Nobody else’s stuff should go there
– Easier to find data/methods and less likely to have data overwritten
• Disadvantages:
– it takes a little time to set up
Example: Chemstation
Data Processing
Saving Raw Data I
• Raw Chromatographic data consists of time and
response(s) (response for a single channel
instrument to responses for multichannel
instruments)
• Most software programs allow you to obtain raw
data
• For some instruments (Buck GC), data presented
using Excel looks nicer than software
chromatograms (with the exception of no
integration)
Data Processing
Saving Raw Data II
• Steps in Process:
– Open file (in ChemStation, you need to be in Data
Analysis mode)
Example: Chemstation
Data Processing
Saving Raw Data III
• Steps in Process:
– Look for way to “export” file or “save file as” with the
output being a “text” file (these usually have a .txt
extension)
In ChemStation, text
file made as “CSV”
file
Data Processing
Saving Raw Data IV
• Steps in Process:
– Once in text format, you can open using “notepad”,
but best to move to Excel
– Demonstrate opening Expfil using notepad and in
Excel
Data Processing
Saving Processed Data I
• For Lab Reports, you will want to incorporate
chromatograms
• Besides switching raw data to Excel, you also
can use instrument software plots
In ChemStation: use Graphics →
Copy to Clipboard
The Alternative (used
extensively for these
Powerpoint slides) is SHIFT
Print Screen:
This Copies the Screen
Demonstrate
Both of these methods allow you to
paste chromatograms into other
programs
Data Processing
Saving Processed Data II
• Besides the chromatogram, one often wants
other chromatographic data (e.g. retention time,
peak area, etc.)
• In ChemStation, this can be copied by using the
Control C key
Click and drag over data box
• Then in Excel, the data can be pasted
Data Processing
Data Smoothing in Excel
• Demonstrate using trendline for a running
average and also using average function with
Excel