Friday, 11/19/2010
• Objective: Chromatography Lab!
Get your folder and get ready
to start the
TIMED BELLRINGER QUESTION.
BELL RINGER
5 MINUTES
1. How do plants get energy?
2. Why do leaves change
colors in the fall?
BELL RINGER
4 MINUTES
1. How do plants get energy?
2. Why do leaves change
colors in the fall?
BELL RINGER
3 MINUTES
1. How do plants get energy?
2. Why do leaves change
colors in the fall?
BELL RINGER
2 MINUTES
1. How do plants get energy?
2. Why do leaves change
colors in the fall?
BELL RINGER
1 MINUTE
1. How do plants get energy?
2. Why do leaves change
colors in the fall?
TIME’S UP!!!!!
Paper
Chromatography
Lab
What is Chromatography?
Chromatography is a technique for
separating mixtures into their
components in order to analyze,
identify, purify, and/or quantify the
mixture or components.
• Analyze
Separate
• Identify
• Purify
Mixture
Components
• Quantify
Uses for Chromatography
Chromatography is used by scientists to:
•
Analyze – examine a mixture, its components,
and their relations to one another
• Identify – determine the identity of a mixture or
components based on known components
• Purify – separate components in order to isolate
one of interest for further study
• Quantify – determine the amount of the a mixture
and/or the components present in the sample
Illustration of Chromatography
Separation
Mixture
Components
Uses for Chromatography
Real-life examples of uses for chromatography:
•
Pharmaceutical Company – determine amount of
each chemical found in new product
• Hospital – detect blood or alcohol levels in a
patient’s blood stream
• Law Enforcement – to compare a sample found at
a crime scene to samples from suspects
• Environmental Agency – determine the level of
pollutants in the water supply
• Manufacturing Plant – to purify a chemical
needed to make a product
Overview of the Experiment
Purpose:
• To explain the relationship between pigments
and photosynthesis.
• To predict which pigment colors would be best
for photosynthesis.
Materials List
• 100 mL beaker
• Isopropyl Alcohol (10 mL)
• Chromatography paper
strip
• Spinach leaf solution
– Red leaf lettuce solution
•
•
•
•
•
Disposable Pipette
Pencil
Ruler
Scissors
Tape
Preparing the Chromatography Strips
1. Draw a line 1.5 cm above
the bottom edge of the strip
with the pencil
2. Starting at the line, taper
the bottom of the paper with
scissors.
3. Place 1-2 drops of the
spinach leaf solution on the
starting line and allow to dry
Developing the Chromatograms
• Place the strip in the beaker
• Make sure the solution does
not come above the drop on
your start line
• Fold the top of the strip over
your beaker and tape to keep
in place
• Let strips develop for
approximately 15 minutes
• Remove the strips and let
them dry
RESULTS
• Use the table on your lab handout to analyze your
chromatography strip
• Answer the analysis questions in your lab notebook
Debrief/Wrap Up
Knowledge of Inquiry
*Scientific investigation begin with a
problem but don’t necessarily test a
hypothesis
*There is no single scientific method
*Inquiry procedures are guided by a
question
*All scientists performing the same
procedures may not get the same
results
*Inquiry procedures can influence results
*Conclusions must be consistent with the
data
*Scientific data is not the same as scientific
evidence
*Explanations are developed from the data
and what is known
NOS
*Tentativeness
*Creativity
*Observation vs. Inference
*Subjectivity
*Theory and law
*Socially/culturally embedded
*Empircally based
Suggestions/Comments: