FD Formal Lab Report - 1st Submission
pdf
keyboard_arrow_up
School
University of Minnesota-Twin Cities *
*We aren’t endorsed by this school
Course
1065
Subject
Chemistry
Date
Apr 3, 2024
Type
Pages
7
Uploaded by CorporalBookRabbit40
Finding the Concentration of Two Food Dyes Used In
A Sport Drink (Pedialyte) Using UV/Vis Spectrums
and Calibration Curves
ABC XYZ
Dec 3 (Fall 2021)
I.
Abstract:
The main objective of this lab was to find out the concentration of the two dyes
(red #40 and blue #1) in an artificially colored drink (Pedialyte grape flavor) and recreate
a sample of it. The UV/Vis spectrums of the drink and diluted solutions of the two food
dyes were collected. Calibration curves were formed using the data collected to
determine the concentration of each dyes. The color of drink was then recreated and its
spectrum was then compared to the original drink’s spectrum. At the end of the lab, it was
found that the concentration of the red #40 dye was 3.81*10
-6
M and the concentration of
the blue #1 dye was 5.8*10
-8
M; it was also found that 21.149mL of red #40 dye and
1.45mL of blue #1 dye is needed for 500mL of solution.
II.
Introduction:
In this lab, the final goal was to identify the concentration of the two dyes in a
drink then recreate its color. For its simplistic preparation and usage, UV-Vis
spectrometers are often used in life science laboratories.
1
Light spectrometers are often
used in medical laboratories for analyzing the purity of DNA and RNA and quantitating
them.
2
Proteins, such as DNA and RNA, can absorb light at a certain wavelength; thus,
measuring a different absorbance indicates an impure sample.
3
In this report, the absorbance and wavelength of the Pedialyte drink and diluted
solutions of red #40 and blue #1 dyes were measured to create two calibration curves in
the form of absorbance vs concentration graphs. These graphs were then used to find the
concentration of the dyes and to recreate the color of the original drink.
III.
Experimental:
A UV/Vis spectrometer was set up and plugged into a computer and into Logger
Pro. The cuvette in it was cleaned thoroughly and DI water was used to blank the
spectrometer. The original Pedialyte drink was diluted with a ratio of 1:1 with DI water
and placed into the spectrometer. The data collected from the program was saved.
3
Revisiting absorbance at 230 nm as a protein unfolding probe.
https://www.sciencedirect.com/science/article/pii/S0003269709001894?via%3Dihub
(accessed 28 Nov,
2021)
2
UV/Vis Spectroscopy: Principle, Strengths and Limitations and Applications.
https://www.technologynetworks.com/analysis/articles/uv-vis-spectroscopy-principle-strengths-and-limita
tions-and-applications-349865#D5
(accessed 28 Nov, 2021)
1
UV Vis Life Science Applications in a Nutshell.
https://www.mt.com/us/en/home/library/guides/laboratory-division/life-science/uvvis-toolbox-for-life-scie
nces.html
(accessed 28 Nov, 2021)
Five solutions of the diluted two dyes were prepared each. These samples were
labelled with their calculated concentrations carefully and placed into test tube holders
for next steps. For the blue #1 dye (2.0*10
-5
M), 10mL of DI water was poured into one of
the test tubes, 9mL of DI water and 1mL of blue dye was poured into another test tube,
8mL of DI water and 2mL of blue dye was poured into the next test tube, 7mL of DI
water was added to 3mL of blue dye in the next test tube, and 6mL of DI water with 4mL
of dye was added to the last test tube. The same procedures were repeated for the red #40
dye (9.0*10
-5
M). All ten samples were put through the spectrometer, with rinsing of the
cuvette in between every trial, and the measured absorbance was recorded down on a
table.
For each of the dyes, an absorbance vs concentration graph was created using the
measured absorbance of the samples and their corresponding concentration written on the
test tubes on Google Sheets. Using the trendline function on Google Sheets, a linear
regression line was created with the y-value as the absorbance and the x-value as the
concentration of the solutions. Using this formula, the absorbance of the two dyes in the
original Pedialyte drink was plugged back in to find their concentration. This
concentration was used to calculate the volume of concentrated dyes needed to recreate a
500mL sample of the color of the drink. The synthesized solution was made in a large
beaker.
IV.
Results:
Using the spectrometer, the wavelength and absorbance of the original drink
solution and the diluted dye solutions were collected in table 1.
Table 1:
Wavelength and absorbance of test solutions
Tested Solution
Wavelength (nm)
Absorbance (Au)
Dye 1
628.3
0.117
Dye 2
535.4
0.108
1mL red dye + 9mL water
523.0
0.197
2mL red dye + 8mL water
515.7
0.422
3mL red dye + 7mL water
506.0
0.593
4mL red dye + 6mL water
505.5
0.809
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
1mL blue dye + 9mL water
630.5
0.232
2mL blue dye + 8mL water
629.6
0.464
3mL blue dye + 7mL water
630.1
0.719
4mL blue dye + 6mL water
630.5
0.874
The concentration of all of the diluted dye solutions were calculated as below
using equation 1 (with M
1
as the original concentration of the dye (concentrated), V
1
as
the intended volume of the dye to use, M
2
as the final concentration of the solution (what
was being calculated for), and V
2
as the total volume of the concentration).
M
1
V
1
= M
2
V
2
Equation 1
M
2RED
= M
1
V
1
/V
2
= 0 M
M
2RED
= M
1
V
1
/V
2
=
M
9. 0 * 10
−6
M
2RED
= M
1
V
1
/V
2
=
M
1. 8 * 10
−5
M
2RED
= M
1
V
1
/V
2
=
M
2. 7 * 10
−5
M
2RED
= M
1
V
1
/V
2
=
M
3. 6 * 10
−5
M
2BLUE
= M
1
V
1
/V
2
= 0 M
M
2BLUE
= M
1
V
1
/V
2
=
M
2. 0 * 10
−6
M
2BLUE
= M
1
V
1
/V
2
=
M
4. 0 * 10
−6
M
2BLUE
= M
1
V
1
/V
2
=
M
6. 0 * 10
−6
M
2BLUE
= M
1
V
1
/V
2
=
M
8. 0 * 10
−6
The calculated concentrations of the dyes along with their measured absorbance
was used to create calibration curves and linear regression lines were found. Both linear
regression lines have a coefficient of determination (R
2
) that equals 0.995 for the red dye
and 0.994 for the blue dye. The estimated absorbance of the red dye using its
concentration is calculated with equation 2, and the estimated absorbance of blue dye is
calculated with equation 3.
Figure 1:
Calibration curve of red #40 dye
Equation 2
𝐴 = 21067 * 𝑐 + 0. 0368
Figure 2:
Calibration curve of blue #1 dye
Equation 3
𝐴 = 1. 06𝑒6 * 𝑐 + 0. 0462
Equations 2 and 3 were used to find the concentration of the two dyes in the
original Pedialyte drink. It was found that the concentration of of the red #40 dye in the
drink is 3.81*10
-6
M and the concentration of the blue #1 dye in the drink is 5.8*10
-8
M.
Using equation 1, the needed volume of
9.0*10
-5
M
red dye was 21.149mL and the
needed volume of
2.0*10
-5
M
blue dye was 1.45mL.
V.
Discussion:
As shown in table 1, when placing the Pedialyte drink and diluted solutions of the
dyes in the UV/Vis spectrometer, the wavelength and absorbance of those solutions were
measured. The cuvette used in every trial must be rinsed carefully and placed in the
correct position since light will need to pass through the sample with minimal
obstructions. Atoms in the sample were brought to an excited state by the radiation
released from the spectrometer, and those atoms must absorb some of the radiation to
move into higher energy levels; as a result, the measured wavelength and absorbance of
the solutions were calculated within the spectrometer how much light can pass the
samples.
4
The collected data was then used to create the calibration curves for calculating
the concentration of the two dyes with Beer’s law, which estimates the absorbance of a
solution using its concentration. The x-axis of the calibration curves were the
concentration of the solutions calculated using manipulation of equation 1 looking for
M
2
, and the y-axis of the curve were the corresponding absorbances of those solutions
measured with the UV/Vis spectrometer. Since both of the coefficients of determination
(R
2
) of the equations for red and blue dye were very close to 1, both the equations were
considered to be highly accurate.
Through manipulation of Beer’s law equations (equation 2 & 3), the absorbance
of the original drink’s dyes were used to find their concentrations. After the concentration
of the two dyes were found, equation 1 was used again in order to find the volume needed
to recreate 500mL of the color of the Pedialyte drink. Since the found needed volume of
the
red dye was 21.149mL and the needed volume of
the
blue dye was 1.45mL, 477.5mL
of DI water is needed to be combined with those dyes in order to synthesize 500mL of
the color solution.
However, after running the synthesized solution through the UV/Vis spectrometer,
it was found that the absorbances shown on the spectrometer was different compared to
that of the original drink. A possible factor that could have resulted in calculating an
incorrect amount of dye volume was incorrect concentration of the stock dyes since those
4
What is a UV-Vis Spectrophotometer?
https://www.denovix.com/blog/what-is-a-uv-vis-spectrophotometer/
(accessed 30 Nov, 2021)
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
- Access to all documents
- Unlimited textbook solutions
- 24/7 expert homework help
numbered were the base of all of the calculations.
VI.
Conclusion:
The objective of this lab was to find out the concentration of the two dyes in an
artificially colored drink and synthesize a sample of its color. The concentration of the
red dye was found to be 3.81*10
-6
M, and the concentration of the blue dye was found to
be 5.8*10
-8
M using UV/Vis spectrums and calibration curves. The absorbance spectrums
were used to create calibration curves with Beer’s law. Those calibration curves were
then used to calculate the needed volume of dyes and it was found that 21.149mL of red
#40 dye and 1.45mL of blue #1 dye is needed to synthesize 500mL of the Pedialyte drink.
The lab could have been expanded by repeating the exact same procedures with
different stock concentrations in order to eliminate the possibility of an incorrect stock
concentration.
Skills acquired in this experiment can also have real-life applications such as
practicing accuracy since a small error in the amount of dyes can affect the absorbances
of the solution drastically. In a real life situation, the same need for accuracy is required
when using chemicals, such as when treating a fish tank with algae remover.
VII.
References:
1.
UV Vis Life Science Applications in a Nutshell.
https://www.mt.com/us/en/home/library/guides/laboratory-division/life-science/uvvis-too
lbox-for-life-sciences.html
(accessed 28 Nov, 2021)
2.
UV/Vis Spectroscopy: Principle, Strengths and Limitations and Applications.
https://www.technologynetworks.com/analysis/articles/uv-vis-spectroscopy-principle-stre
ngths-and-limitations-and-applications-349865#D5
(accessed 28 Nov, 2021)
3.
Revisiting absorbance at 230 nm as a protein unfolding probe.
https://www.sciencedirect.com/science/article/pii/S0003269709001894?via%3Dihub
(accessed 28 Nov, 2021)
4.
What is a UV-Vis Spectrophotometer?
https://www.denovix.com/blog/what-is-a-uv-vis-spectrophotometer/
(accessed 30 Nov,
2021)
Related Documents
Related Questions
2. Peaks resulting transitions
from n → TT* are shifted to
shorter wavelengths (blue shift)
with an increasing of solvent
polarity. *
True
False
arrow_forward
In order to measure riboflavin in a breakfast cereal, a 5.00-gram sample of the cereal was extracted with acetic acid and filtered. The extract was transferred to a 50.0 mL volumetric flask and diluted to the mark. The sample was transferred to a cuvette and the fluorescence was measured. The instrument read 59 units (Fluorescence units –an arbitrary scale). 24.00 mL of the cereal extract was sample was mixed with 1.0 mL of a riboflavin standard that was 0.500 ug/mL. The fluorescence of this mixture was measured and read 94 fluorescence units. Calculate the concentration of riboflavin per gram of cereal (use µg/gram of cereal).
arrow_forward
Carbon monoxide is another common poison found in the forensic laboratory. Explain how UV-visible spectrophotometry is applied to quantify carbon monoxide in blood samples.
arrow_forward
Potassium dichromate and potassium permanganate have overlapping absorption spectra in 1M H2SO4. K2Cr2O7 has an absorption maximum at 440 nm, and KMnO4 has a band at 545 nm (the maximum is actually 525 nm, but using the longer wavelength is advantageous because interference from K2Cr2O7 is less). A mixture is analyzed by measuring the absorbance at these two wavelengths with the following results: A440= 0.405, A545= 0.712 in a 1-cm cell (actually as long as all the measurements are made in the same cell, for problems such as this, the exact pathlength cancels out in the calculations). The absorbance of pure solutions of K2Cr2O7 (1.00x10-3M) and KMnO4 (2.00x10- 4M) in 1 M H2SO4, using the same cell gave the following results: ACr2O7,440= 0.374, ACr2O7,545= 0.009, AMnO4,440= 0.019, AMnO4,545= 0.475. Calculate the concentrations of dichromate and permanganate in the sample solution.
arrow_forward
The data given below was generated by a student in Bio 240L during a Bradford
Assay. A standard curve was generated by preparing a set of standard samples of
protein (bovine serum albumin) and adding the dye Coomassie Brilliant Blue, When
the protein binds to Coomassie Brilliant Blue it absorbed light at 595 nm with an
extinction coefficient of 43,000 M-1 cm-1. After the dye binding reaction was
complete, absorbance values for each protein standard solution were measured at
595 nm and recorded.
Standard #
1
2
13
4
Concentration of protein binded
to Coomassie Brilliant Blue (M)
6.35x10-7
1.23x10-6
3.85x10-6
5.68x10-6
OOO
Absorbance at 595 nm
0.093
0.176
0.560
0.813
Prepare a standard curve with the student generated data. What is the slope from
the standard curve rounded to four sig figs and no units?
1.4
143398
6.972x10-6
1.434x105
arrow_forward
The IR spectrum of 2-methyl-1-butanol (H;CCH,CH(CH;)
CH,OH) and tert-butyl methyl ether [(CH;);COCH3] are
shown below. Assign cach spectrum to the correct com-
pound and identify the frequencies and the functional
groups used to support your assignment.
λ (μm)
6 7 8 9 10 11 12 1314 15
2.5
100
3
5
90
80
70
60
50
40
30
20
10
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000
800
600
400
Frequency (cm-1)
A (µm)
7 8 9 10 11 12 13 14 15
2.5
100
3
5
20
4
6
90
80
70
60
50
40
30
20
10
4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000
800
600
400
Frequency (cm¬!)
(%) Transmission
(%) Transmission
20
arrow_forward
Infrared Spectroscopy (IR) is very useful for determining the functional groups present
in an organic molecule. For each of the spectra below, complete the following:
• Build the molecule in Spartan and describe the motion of the molecule at each key
absorption frequency
• Identify key absorption frequencies in the spectrum and identify the type of
stretch/bend/wag/etc. (i.e. O-H)
•
Match the spectra from the provided structures
•
Identify the main functional groups in the molecule
OH
A
OH
H
B
E
F
H
N
NH2
arrow_forward
If a radiation intensity l0 = 2.5x1010 fotones s-1 cm2 causes a dissolución and an absorbance of 0.95 will be recorded. How much incident radiation is absorbed by the music screen?
arrow_forward
In the equation, A = ebc, what quantity is represented by e? Molar Absorbtivity. Transmittance. Concentration.
arrow_forward
3. The change in frequency produced by the Doppler shift when a sound source of
frequency f is moving with velocity v toward a fixed observer is given by
fv
Af
(u-v)
and v and their uncertainties, calculate Af and its uncertainty. Which, if any, of
where u is the velocity of sound. From the following values of u, f,
the uncertainties make a negligible contribution to the uncertainty in Af ?
u = (332 ± 8) m s1; f = (1000 ± 1) Hz; and v = (0.123 ± 0.003) m s1
arrow_forward
The intensity of light passing
through a 1.00-cm sample of a
solution of polystyrene in methyl
ethyl ketone was observed to
decrease by O.9%. The
concentration of the solution was
10.6 kgm-3. Given A =546.1 nm,
no= 1.377, and dn/dC" = 2.20x 10-4
%3D
m3/ kg. calculate the molar mass of
the polystyrene in kg/mol.
The relative displacement (r/ro) of
bovine serum albumin was observed
as a function of time:
t (s) 700
3580 4540 5020
r/r. 1.0129 1.0679 1.0871 1.0965
6 260 /s, find the
sedimentation coefficient. Assuming
Given w =
v = 7.34x 10 3 m3 kg and p = 9.93 x
102 kg/m3, diffusivity = 6.97 x 1011
m2/s at 25 °C, determine the molar
%3D
mass of the sample in kg/mol.
arrow_forward
1-31. We shall learn when we study molecular spectroscopy that heteronuclear diatomic
molecules absorb radiation in the microwave region and that one determines directly the
so-called rotational constant of the molecule defined by
B =
8721
where I is the moment of inertia of the molecule. Given that B = 3.13 × 105 MHz for H35C1,
calculate the internuclear separation for H35C1. The atomic mass of H and 35C1 are 1.008
and 34.97, respectively.
arrow_forward
SEE MORE QUESTIONS
Recommended textbooks for you
Principles of Modern Chemistry
Chemistry
ISBN:9781305079113
Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler
Publisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning
Related Questions
- 2. Peaks resulting transitions from n → TT* are shifted to shorter wavelengths (blue shift) with an increasing of solvent polarity. * True Falsearrow_forwardIn order to measure riboflavin in a breakfast cereal, a 5.00-gram sample of the cereal was extracted with acetic acid and filtered. The extract was transferred to a 50.0 mL volumetric flask and diluted to the mark. The sample was transferred to a cuvette and the fluorescence was measured. The instrument read 59 units (Fluorescence units –an arbitrary scale). 24.00 mL of the cereal extract was sample was mixed with 1.0 mL of a riboflavin standard that was 0.500 ug/mL. The fluorescence of this mixture was measured and read 94 fluorescence units. Calculate the concentration of riboflavin per gram of cereal (use µg/gram of cereal).arrow_forwardCarbon monoxide is another common poison found in the forensic laboratory. Explain how UV-visible spectrophotometry is applied to quantify carbon monoxide in blood samples.arrow_forward
- Potassium dichromate and potassium permanganate have overlapping absorption spectra in 1M H2SO4. K2Cr2O7 has an absorption maximum at 440 nm, and KMnO4 has a band at 545 nm (the maximum is actually 525 nm, but using the longer wavelength is advantageous because interference from K2Cr2O7 is less). A mixture is analyzed by measuring the absorbance at these two wavelengths with the following results: A440= 0.405, A545= 0.712 in a 1-cm cell (actually as long as all the measurements are made in the same cell, for problems such as this, the exact pathlength cancels out in the calculations). The absorbance of pure solutions of K2Cr2O7 (1.00x10-3M) and KMnO4 (2.00x10- 4M) in 1 M H2SO4, using the same cell gave the following results: ACr2O7,440= 0.374, ACr2O7,545= 0.009, AMnO4,440= 0.019, AMnO4,545= 0.475. Calculate the concentrations of dichromate and permanganate in the sample solution.arrow_forwardThe data given below was generated by a student in Bio 240L during a Bradford Assay. A standard curve was generated by preparing a set of standard samples of protein (bovine serum albumin) and adding the dye Coomassie Brilliant Blue, When the protein binds to Coomassie Brilliant Blue it absorbed light at 595 nm with an extinction coefficient of 43,000 M-1 cm-1. After the dye binding reaction was complete, absorbance values for each protein standard solution were measured at 595 nm and recorded. Standard # 1 2 13 4 Concentration of protein binded to Coomassie Brilliant Blue (M) 6.35x10-7 1.23x10-6 3.85x10-6 5.68x10-6 OOO Absorbance at 595 nm 0.093 0.176 0.560 0.813 Prepare a standard curve with the student generated data. What is the slope from the standard curve rounded to four sig figs and no units? 1.4 143398 6.972x10-6 1.434x105arrow_forwardThe IR spectrum of 2-methyl-1-butanol (H;CCH,CH(CH;) CH,OH) and tert-butyl methyl ether [(CH;);COCH3] are shown below. Assign cach spectrum to the correct com- pound and identify the frequencies and the functional groups used to support your assignment. λ (μm) 6 7 8 9 10 11 12 1314 15 2.5 100 3 5 90 80 70 60 50 40 30 20 10 4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400 Frequency (cm-1) A (µm) 7 8 9 10 11 12 13 14 15 2.5 100 3 5 20 4 6 90 80 70 60 50 40 30 20 10 4000 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400 Frequency (cm¬!) (%) Transmission (%) Transmission 20arrow_forward
- Infrared Spectroscopy (IR) is very useful for determining the functional groups present in an organic molecule. For each of the spectra below, complete the following: • Build the molecule in Spartan and describe the motion of the molecule at each key absorption frequency • Identify key absorption frequencies in the spectrum and identify the type of stretch/bend/wag/etc. (i.e. O-H) • Match the spectra from the provided structures • Identify the main functional groups in the molecule OH A OH H B E F H N NH2arrow_forwardIf a radiation intensity l0 = 2.5x1010 fotones s-1 cm2 causes a dissolución and an absorbance of 0.95 will be recorded. How much incident radiation is absorbed by the music screen?arrow_forwardIn the equation, A = ebc, what quantity is represented by e? Molar Absorbtivity. Transmittance. Concentration.arrow_forward
- 3. The change in frequency produced by the Doppler shift when a sound source of frequency f is moving with velocity v toward a fixed observer is given by fv Af (u-v) and v and their uncertainties, calculate Af and its uncertainty. Which, if any, of where u is the velocity of sound. From the following values of u, f, the uncertainties make a negligible contribution to the uncertainty in Af ? u = (332 ± 8) m s1; f = (1000 ± 1) Hz; and v = (0.123 ± 0.003) m s1arrow_forwardThe intensity of light passing through a 1.00-cm sample of a solution of polystyrene in methyl ethyl ketone was observed to decrease by O.9%. The concentration of the solution was 10.6 kgm-3. Given A =546.1 nm, no= 1.377, and dn/dC" = 2.20x 10-4 %3D m3/ kg. calculate the molar mass of the polystyrene in kg/mol. The relative displacement (r/ro) of bovine serum albumin was observed as a function of time: t (s) 700 3580 4540 5020 r/r. 1.0129 1.0679 1.0871 1.0965 6 260 /s, find the sedimentation coefficient. Assuming Given w = v = 7.34x 10 3 m3 kg and p = 9.93 x 102 kg/m3, diffusivity = 6.97 x 1011 m2/s at 25 °C, determine the molar %3D mass of the sample in kg/mol.arrow_forward1-31. We shall learn when we study molecular spectroscopy that heteronuclear diatomic molecules absorb radiation in the microwave region and that one determines directly the so-called rotational constant of the molecule defined by B = 8721 where I is the moment of inertia of the molecule. Given that B = 3.13 × 105 MHz for H35C1, calculate the internuclear separation for H35C1. The atomic mass of H and 35C1 are 1.008 and 34.97, respectively.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- Principles of Modern ChemistryChemistryISBN:9781305079113Author:David W. Oxtoby, H. Pat Gillis, Laurie J. ButlerPublisher:Cengage LearningPrinciples of Instrumental AnalysisChemistryISBN:9781305577213Author:Douglas A. Skoog, F. James Holler, Stanley R. CrouchPublisher:Cengage Learning
Principles of Modern Chemistry
Chemistry
ISBN:9781305079113
Author:David W. Oxtoby, H. Pat Gillis, Laurie J. Butler
Publisher:Cengage Learning
Principles of Instrumental Analysis
Chemistry
ISBN:9781305577213
Author:Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:Cengage Learning