IGCSE Coordinated Science Y1
Topic: Methods of
Separation & Purification
Monday, August 27th
Lesson 1
IN:
• Return to your lab station with your
partner(s) and wrap up your separation
lab.
• When you have obtained all 4 mixture
components in plastic cups, clean up the
rest of your lab materials and get checked
off by Miss James.
– Wash beakers, spoons, etc.
THROUGH:
C2 Vocabulary
• Before we talk about another method of
separation, please get out your C2
vocabulary for Miss James to check off!
Chromatography
• Today’s method for separation is
chromatography!
• Let’s go through the To “Dye” For Lab and
discuss some background and technique
information you’ll need to do your lab
today!
To “Dye” For Lab
Separating Mixtures Using
Chromatography
The Problem
• A lawsuit is pending between crayon and
marker giant Crayola™ and the overhead
pen/marker industry which includes
Staedtler™, Monami, and Vis-a-Vis™.
The various pen makers are claiming that
Crayola™ has stolen their proprietary dye
mixtures to use in their markers.
Your Challenge...
• You have been hired by the court as an
independent consultant to use separation
techniques that will analyze the
components in the dye mixtures found in
the pens and markers from each maker.
Your findings should help clarify for the
court whether or not a lawsuit is
warranted.
The Science Behind Chromatography
• Chromatography means “Color Writing”
• Chromatography uses the properties of
Solubility and Polarity to separate mixtures.
• There is a stationary phase (filter paper) and
a mobile phase (water).
• Pigments that are more attracted to the
mobile phase will travel farther across the
medium than those attracted to the stationary
phase.
Real Life Uses of Chromatography
• Observation of mixtures and solvents
• To determine the identity of unknown
substances
• To determine what is in a solid or liquid
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–
–
–
Finding the presence of cocaine in urine
Detecting alcohol in blood
Finding toxins in fish
Detecting lead in water
• Chromatography is used in crime solving!
Procedure
1. Fold your filter paper so that you have 4 equal
wedges (each wedge will contain a different color
ink).
2. Fold your paper opposite the first folds so that the
filter paper lays flat.
3. Using a PENCIL, trace a 500 won piece in the center
of your filter—there will be NO marks here!
4. In one wedge, tap each marker of one color to the
filter paper and label each dot near the outer edge of
the filter paper. The smaller the dot the better!
5. Rest your paper on top of a large (250mL) beaker.
6. Use a pipet to tap small drops of water to the center
of the filter paper.
7. Observe!
OUT/Conclusion:
• Answer the following question:
– Do Visa-Vis™, Monami, and Staedtler™ have
a case against Crayola™?
– Use observational “data” from your
experiment to support your conclusion.
Appropriate data means detailed observations
or drawings/sketches of your chromatograms.