two of the experiment we took the absorbance of the two different dyes. We
decided to make 5 different dilutions of Yellow 5 and Blue 1 so I could make an
accurate graph for the concentrations versus absorbance. From making five different
dilutions of each dye we able to take the absorbance of the different concentrations,
and we were able to make two different plots one for Yellow 5 and one for Blue 1.
Each plot consists of the absorbance versus concentration of each dye at their
lambda max. After making these linear graphs we were able to find the y=mx + b
equation for each dye. The slope of the equation, m, is also Ԑ. Plugging Ԑ in for Y
allowed us to solve for x. From finding x we were able to find the % by mass in G2
lemon-lime and the mass per serving for each dye present. From the calculations we
found that there is slightly more FD&C Yellow 5 dye in the G2 lemon-lime Gatorade.
We can assume this because the % by mass and serving size of the Yellow 5 dye are
greater than those of the Blue 1, also the Gatorade is more yellow than yellow-green
so it makes sense that there is more Yellow 5 dye in the Gatorade than the Blue 1.
2.
In order to do the calculations assuming no interference between the two species I
used the equation Ԑ=A/C. For Red 3 I found Ԑ by using the slope of the graph with
the Red 3 concentration at the Red 3 lambda max. The other information I needed to
solve for C was A the absorbance which we found in step 9 from using the
SpectroVis Spectrometer. A/ Ԑ gave use the concentration with no interference.
When finding the concentration of Yellow 6 I did the exact same thing however, I
used the slope on the Yellow 6 at the Yellow 6 concentration lambda max and the
absorbance of Yellow 6. The concentration for Yellow 6 at Yellow 6’s lambda max is
0.0425 ppm. The concentration for Red 3 at Red 3’s lambda max is 0.0544 ppm. The
lambda max for Red 3 is higher because it has a higher wavelength at 532.44 nm.

#### You've reached the end of your free preview.

Want to read all 3 pages?

- Fall '11
- U
- Chemistry, pH, Yellow, Food coloring, E number, Food colorings, fd&c yellow, Cassie Pressnall