Maram Alfi, Salma Omar, & Kayla Phillips
January, 26, 2010
General Chemistry 110 lab
Yumi Matsumura
Using Paper Chromatography in different solvents to know the Types of Dyes that are used in
Food
Abstract
Paper Chromatography is used to know the different types of dyes that are used in food. A lot
of companies use dyes to make food colorful. In order to separate the dyes in food, solvents
can be used. With the variety of solvents- alcohol, water, and table salt- there is one of these
solvents that can separate the dyes in a precise way that the dyes can be seen separated from
each other. When separating dyes, the amount of solvent should be precise depending on how
much dyes are used. In this procedure, three types of solvent were used, which were: water,
alcohol, and 0.10% table salt. Each of these solvents reacted to the dyes in different ways. The
dyes that were used were: blue 1, blue 2, yellow5, yellow 6, red 3, red 40, and green3.
Moreover, there was some mixing of two types of dyes together. The water and the table salt
were similar when they were used in the results. However, table salt was clearer in the
separation of the dyes than the water. The table slat distance was 5.2 cm, while the water was
5 cm. The table salt was clearer in separating the dyes than the water. Moreover, when using
the retention factor, the table salt was more precise than the water.
Introduction
Some food has more than one type of dye. Paper Chromatography is used to know how many
types of dye are used in the food and if there is dye in the food. The separation of the dye can
happen through the chromatography and using several types of solvents. Paper
chromatography is used to “separate components to their original parts”. There are two phases
in chromatography: stationary phase and mobile phase (Stranz, 2008). The chromatography,
with the dyes on it, and after putting the paper in the solvent, the dyes started to be separated.
The dyes, which are mixtures, separated to be clearer to see what the two colors were. The
paper chromatography helped to identify which dyes were used. The molecule of the paper
chromatography attracts the solvent that is used, such as water (Stranz, 2008). When the
solvent is attracted to the paper, then the stationary phase occur (Stranz, 2008).
As there is the mobile phase and the stationary phase, the following equation explains how
there can be equilibrium: component – mobile phase
component- stationary phase. (Stranz,
2008). The following equation explains the retention value when for chromatography. Rf=
distance traveled by component. The equation shows the value of the equilibrium. The purpose
of this equation is to show the how much the solvent is clear in showing the dye and the
mixture of unknown dyes. The hypothesis of this equation is to know which of the various
solvents, is the best to show the dye in a clear way.
Experimental Method
The Signature Lab Series was the book that was used to follow the procedure for this
experiment. The tools that were used for this experiment were: Beaker, a plate for the dyes,
the paper chromatography, toothpicks, dyes, ruler, and a pencil. First, the dyes were on the
plate placed by order to know which dye was the one that was used. After that, the paper was
prepared with the measures that were required in the book. Using a tooth pick the dye was
placed on the paper. After putting the dyes on the paper, the paper was shaped to a cylinder
shape and stapled. Using the beakers, every solvent that was being used, was placed in the
beaker with specific measurements. The solvents were: water, alcohol, and table salt. Each one
of the paper chromatography that has been prepared is placed in each solvent. The paper left
in the solvent until it reaches the point that was decided.
Results
After the solvent took the time to reach the specific point, the paper has been moved from the
solvent to the table carefully and left to dry. After the paper is dried, using a ruler, the
measurements are being taken. The first solvent that was done is the water. The water took 7
minutes to reach the point that was deiced on the paper. The starting time for the water was
10:38 A.M. and ending time was 10:45 A.M. The water moved 5 cm.
Table one
FD&C dyes
Distance spot moved, cm
Rf
Blue 1
4.7 cm
0.94 cm
Blue 2
4.5 cm
0.9 cm
Yellow 5
4.9 cm
0.98 cm
Yellow 6
5.0 cm
1 cm
Red 3
1.9 cm
0.38 cm
Red 40
4.2 cm
0.84 cm
Green 3
5.9 cm
1.18 cm
Blue 1
4.5 cm
0.9 cm
Red 40
5.0 cm
1 cm
Blue 1 and Red 40
Blue 1 and Yellow 5
Blue 1
4.1 cm
0.82 cm
Yellow 5
5.4 cm
1.08 cm
Red 3
2.0 cm
0.4 cm
Yellow 6
4.8 cm
0.96 cm
Blue 2
4.1 cm
0.82 cm
Yellow 5
5.4 cm
1.08 cm
Red 3 and Yellow 6
Blue 2 and Yellow 5
The second solvent was the table salt. The table salt took 9 minutes to get to the point that
was decided on the paper. The starting time for the table salt was 10:38 A.M. and ending time
was 10:47 A.M. The table salt moved 5.2 cm. The table salt was the best solvent out of the two
other solvents which were: water and alcohol. The table salt was the one chosen for continuing
separating the unknown dyes.
Table two
FD&C dyes
Distance spot moved, cm
Rf
Blue 1
1.25 cm
0.24 cm
Blue 2
.75 cm
0.14 cm
Yellow 5
.75 cm
0.14 cm
Yellow 6
.65 cm
.125 cm
Red 3
.25 cm
0.0480 cm
Red 40
1.5 cm
0.288 cm
Green 3
.5 cm
.096 cm
Blue 1
1 cm
0.192 cm
Red 40
1 cm
0.192 cm
1 cm
0.192 cm
.25 cm
0.0480 cm
.5 cm
0.096 cm
1.25 cm
0.240 cm
Blue 2
1.1 cm
0. 211 cm
Yellow 5
.75 cm
.14 cm
Blue 1 and Red 40
Blue 1 and Yellow 5
Blue 1
Yellow 5
Red 3 and Yellow 6
Red 3
Yellow 6
Blue 2 and Yellow 5
Finally, alcohol took the longest time to reach the specific point on the paper. The starting time
for the alcohol was 10:38 A.M. and ending time was 11:35 A.M. The alcohol moved 3.3 cm.
Alcohol was the least clear solvent.
Table three
FD&C dyes
Blue 1
Distance spot moved, cm
Rf
.5 cm
0.151 cm
Blue 2
.5 cm
0.151 cm
Yellow 5
.75 cm
0.22cm
Yellow 6
.25cm
.075 cm
Red 3
.1 cm
0.030 cm
Red 40
.5 cm
0.151 cm
Green 3
.3 cm
.090 cm
Blue 1
.5 cm
0.151 cm
Red 40
.5 cm
0.151 cm
Blue 1
.6 cm
0.181 cm
Yellow 5
.6 cm
0.181 cm
Red 3
.1 cm
0.030 cm
Yellow 6
.5 cm
0.151 cm
Blue 2
.7 cm
0. 212 cm
Yellow 5
.4 cm
0.121 cm
Blue 1 and Red 40
Blue 1 and Yellow 5
Red 3 and Yellow 6
Blue 2 and Yellow 5
Discussion
The final result of the solvents was surprising. Mostly, water was the most aspect that was
moving faster than the other solvents. However, the table salt was the clearest solvent to show
the dyes. At the beginning of the paper chromatography, the water was the fastest solvent;
however, the table salt was the clearest solvent. Especially after calculating the Rf value for
both the water and the table salt. The table salt was more specific than the water. There were
huge difference between the water and the alcohol. Also, there were huge difference between
the table salt and alcohol. When looking at the distance for every solvent, the solvent that went
further was the best solvent to continue with. When looking at the water and table salt results,
both of the water and the table salt were really close to each other. When looking at table one
“the water table” and table two “the table salt table”, red 3 Rf value had close results in water
and table salt. In water column number five was 0.38 cm and in table salt it was 0.48 cm. When
calculating the Rf value, there were some mistakes, such as using the wrong columns in the
data sheet, Which gave the wrong results.
Reference
Stranz, M. (2008). Signature Labs Series. Chem 110.