Sadly not all of my pretty pictures copied over - but you'll get the general idea!
Chemiluminescence
Linda Southard
Nora Mena
Chem 151L-005
Pete Golden
Introduction
The
objective of this lab was for our group to identify which chemicals, when mixed
together, we could get to glow. The
group additionally was trying to determine in what ratios it would take to make
these chemicals glow. Finally, the
group will be attempting to find out which of the chemicals, and in which
ratios, will glow for a longer period of time as well as which ones will glow
brightest.
Chemiluminescence
is the formation of energy, in the form of a matter we call light. This is based on a reaction of chemicals
mixed together.
Chemiluminescence
is used in a variety of ways. Some of
the ways that Chemiluminescence is used
in the scientific world is to analysis an inorganic substance/species in that
of a liquid phase. It can also be used
in the detection of biomolecules, which are any molecules produced from any
living organism, in some systems like ELISA (Enzyme-lined immunosorbent
assy. ELISA is a popular format when doing “wet-lab" for
the detection of the presence of a substance).
Additionally, it is used while working along with DNA.
In other capacities, Chemiluminescence is used for the
Military while working on Land Navigation training as well as for movements in
war times while wanting to maintain “lights out”. Although we like to refer to
them as Glow sticks, the U.S. Navy were actually the first to develop the
“light stick” method. The Navy developed
them as a subtle and easily concealed form of illumination for those who
participated in their special ops, Navy SEALS units when they were dropped
behind enemy lines. It is also used in
the Law Enforcement Field while working on murder cases (DNA – Blood) as well
as search and rescue divers in muddy waters.
Families use this while they are camping for markers, safety and some
people in hurricane or tornado prone areas keep them in their safety and first
aid kits.
Finally, Chemiluminescence is used in what all children,
both young and old, love to play with no matter what time of year it is. You can find them at fairs, festivals,
amusements parks and even in your local Dollar Tree. These are Glow Sticks.
Going back to families and Chemiluminescence, a family
can observe it while camping as well as while using it themselves. While families are out camping, most likely
they would see a firefly. Male
fireflies, aka lightening bugs, emit a yellow to green color during their
mating process. Yet another way a family
might see Chemiluminescence in nature is by way of taking a hike and coming
across a click beetle or a railway worm.
Click Beetles will emit a green to orange glow while the Railway Worm
will emit a red light unless they are moving and then they will emit a green
light.
If you were to go on a deep sea diving expedition or were one of the
persons who were researching the Titanic, then you would have experienced
another form of Chemiluminescence. You
would have possibly come across a Jellyfish or other Creatures of the deep.
The fundamentals of
this experiment are that the group will take luminol from a powder state, 0.1 g
mixed with 1M NaOH [Sodium Hydroxide] until dissolved. Next, they will pour that in to a Volumetric
Flask and add enough distilled water to mix it until it is a full 50 mL
mixture. This will be their stock solution. The group will then introduce via pipettes, their
stock solution to different chemicals and or solutions in a well plate. The group will then observe how each solution
or chemical interacts with the other(s).
They will record the results and determine if their solutions can make a
form of chemiluminescence. The end result and the goal of this experiment
is to see which ones they can get to glow the brightest and which will glow the
longest.
Within
this experiment the group will be working with different variables. They will be working with Chemicals,
Compounds and solutions. Some of the
products they will use will be: NaClO (Bleach), H2O2
(Hydrogen Peroxide), DMSO (dimethylsulfoxide), 1M HCl (hydrochloric acid) as
well as H2O (water). (See Fig
1-5.)
Fig. 1 Fig.2
Fig. 3 Fig. 4 Fig. 5
Clorox Bleach Hydrogen Dimethylsulfoxide Hydrochloric Water
Peroxide
Acid
These are just some of
the substances that will be used and worked with in the experiment. An array of additional chemicals will be
available to the group should they decide that they would like to make an
attempt to try them. Within the
experiment, these variables will change by way of how much of the stock
solution is utilized as well as which chemicals or solutions and how much of
each one is used. The group will control
the amounts of each and will report back as to what the results were.
RESULTS
Day
One Trial
The orders in which the
products, chemical and solutions are listed in table 1.1 are the order in which
each product, solution, or chemical was placed into the well plate. Those that show a Zero are ones that were
available to the group however none were used in that particular test. Each test was started with the luminol stock
solution being the first to go in to the well plate. Peroxide was always the second to go in,
followed by Bleach each time and then Water.
Table 1.1
Test #
|
Luminol
|
H2O2
|
NaClO
|
H2O
|
DMSO
|
1M HCl
|
Luminol
|
NaClO
|
1
|
1 drop
|
1 drop
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
1 drop
|
2
|
2 drops
|
2 drops
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
2 drops
|
3
|
3 drops
|
3 drops
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
3 drops
|
4
|
4 drops
|
4 drops
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
4 drops
|
5
|
5 drops
|
5 drops
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
5 drops
|
6
|
6 drops
|
6 drops
|
1 drop
|
1 drop
|
Zero
|
Zero
|
3 drops
|
6 drops
|
KEY:
Luminol = the Luminol Stock Solution
H2O2 = Hydrogen
Peroxide
NaClO = Bleach
H2O = Water
DMSO = Dimethysulfoxide
1M HCl = Hydrochloric Acid
You
will notice that there is an additional column for Luminol as well as
Bleach. After the initial drops, the
group then added additional Luminol and Bleach.
Therefore, they too are included in the order in which they were dropped
by pipette into the well plate.
In table 1.2, you will see the results
of each test with the brightness, on a scale of 0-5 as well as the length of
time for each reaction.
Table 1.2
Test #
|
Brightness
|
Length Glow
|
1
|
|
Millisecond
|
2
|
|
Millisecond
|
3
|
|
Millisecond
|
4
|
|
Millisecond
|
5
|
|
Millisecond
|
6
|
|
Millisecond
|
Brightness Scale Zero to Five, with five
being the brightest
0 1 2 3 4 5
Day
Two Trial
The orders in which the
products, chemical and solutions are listed in table 2.1 are the order in which
each product was placed into the 50 mL beaker.
Our group had opted to utilized information that we had found on line
while doing further research. The group
used the remaining portion of the Luminol Stock Solution from the previous
week. Additionally we used some cobalt –
to no avail. The only products that gave
our group any semblance of chemiluminescence are the ones listed on table
2.1.
Day two was started
with a 50 mL beaker with measured out 30 mL of H2O. Following the water, Bleach was added and
finally the Luminol Stock Solution. The
tests that follow are the increments in which the additional products were
added and always in the order listed.
Table 2.1
Test #
|
H2O
|
NaClO
|
Luminol
|
Brightness
|
Time
|
1
|
30 mL
|
1 drop
|
20 drops
|
|
Flash
|
2
|
Zero
|
1 drop
|
20 drops
|
|
Flash
|
3
|
Zero
|
1 drop
|
10 drops
|
|
2-3 seconds
|
4
|
Zero
|
1 drop
|
10 drops
|
|
5-6 seconds
|
5
|
Zero
|
1 drop
|
10 drops
|
|
7 seconds
|
6
|
Zero
|
1 drop
|
10 drops
|
|
8 seconds
|
7
|
Zero
|
1 drop
|
10 drops
|
|
15-20 seconds
|
Brightness Scale Zero to Five, with five
being the brightest
0 1 2 3 4 5
KEY:
Luminol = the Luminol Stock Solution
NaClO = Bleach
H2O = Water
When working with chemicals, you
have to be more careful than if you are brushing your teeth. You need to be sure that you aren’t mixing
things that shouldn’t be mixed together as well and knowing what you should do
if you happen to spill a chemical on your person, your work station or
accidently consume the chemical. One way
to ensure that should any hazards happen, i.e. spills etc. is to keep your MSDS
on hand. An MSDS is the Materials Safety
Data Sheet. The MSDS are used whenever
you feel you need additional information about any hazardous material or
chemical you are working with that is not listed on the products label. Below are the Chemical Structure of Luminol
and the MSDS follows.
Luminol
Luminol is a yellow to
green powder, sometimes white. Luminol
causes eye, skin as well as respiratory tract irritations. The Targeted organs of the human body are the
eyes, skin, and mucous membranes.
Some of the potential Health effects include but are not
limited to the following:
Eyes: Eye irritation
Skin: Skin irritation
Ingested: Gastrointestinal irritation with nausea,
vomiting and diarrhea
Inhalation: Respiratory tract irritation
In the event of contact,
persons should do the following:
Contact with the eyes: immediately flush eyes with water for at
least 15 minutes contact Poison Control and seek medical aid.
Contact with the
skin: Flush plenty of water over the skin
and remove contaminated clothing/shoes.
Contact Poison Control and seek medical attention if irritation develops
and persists. Wash contaminated clothing
prior to wearing again.
If Luminol is
ingested: Contact Poison Control and
seek medical attention. Do not induce
vomiting unless directed to do so by medical personnel.
If Luminol is
inhaled: Immediately move to cleaner
fresher air. If person who inhaled
luminol is not breathing, begin CPR. If
person who inhaled luminol is breathing yet with difficulty, administer oxygen
and see medical attention.
The
trial that our group had with the best results was those of day two
trials. We were able to get a 15-20
second “glow” after our seventh step to this trial. In this trial, we used a total of 30 mL of H2O,
with a total of 7 drops of NaClO and 90 drops of Luminol Stock Solution. We began with the 30 mL of water then dropped
in by drops from a pipette the Bleach and then the Luminol Stock Solution. This ratio was chosen due to the fact that we
were able to get a longer lasting glow which lasted for 15-20 seconds. Again, we started with the 30 mL of H2O,
1 drop of NaClO and 20 drops of Luminol Stock Solution (Luminol). After the initial test, we decided to add one
more drop of NaClO followed by another 20 drops of Luminol. Still not satisfied, we again added one drop
of NaClO followed by another ten drops of Luminol. Seeing more of a result, we decided that we
would try to further our results. We
again added one drop NaClO to ten more drops of Luminol. We noticed more of a glow for a little longer
of a time so we thought what the heck, let’s go for more. We again added only the one drop of NaClO
followed by ten more drops of Luminol.
We were satisfied but wanted to go further! Again we added one drop of NaClO to ten more
drops of Luminol. At this point we had a
really nice glow that went for 15-20 seconds and was a nice brightness. Attempting to see if we could get one to glow
for longer, we added additional Bleach and Luminol in the same one and ten
drops ratios yet by this time we were unable to get better results due to the
solution became a weakened state.
Oddly,
at this point we felt that we were done and decided that we would just amuse
ourselves so we began to just mix everything we had, the remainder of our
Luminol Stock Solution, Cobalt, Hydrogen Peroxide, Water, Dimethysulfoxide,
Hydrochloric Acid and Bleach. At this
point, we actually got our best results.
We sadly did not have any measurements for these. Every time we added a drop of bleach, we
would get a flash of bright green under the meniscus of the fluid while we
would get a bright purple flash on the top.
Again we thought we were done so we didn’t take any measurements, just
poured and had fun! Sadly though, it was
our best one.
When
we did day one trials, we put all of the luminol in first; this didn’t really
generate anything fascinating that was really something to write home
about. We were producing flashes but
nothing substantial. When we researched
to see what else we could do, we came to day two trials and began our trial
with water and ended it with the Luminol.
By using this sequence of adding the chemicals, we were able to get a
brighter and longer lasting color. We
also utilized the same Luminol Stock Solution that we made from day one
trials. Our Luminol stock solution was
that of 0.1 g powdered luminol which we added to 1M NaOH until dissolved. Once dissolved, we poured it in to Volumetric
Flask and added enough distilled water to make a 50 mL solution. This solution was used for BOTH trials. It held up rather well.
In
day one trials, we made an error in not trying to add the chemicals/solutions
in any other order. We continuously
added them in the same order just different amounts. We should have tried to add them in different
orders, not the same over and over again.
By changing the order up some, we would have gotten different results
and possibly a better or best result.
In
day two trials, we made the biggest error in thinking that we were done. We should have still measured our additions
even though we were amusing ourselves.
Had we taken measurements on the final additions and in what order we
did it, we could have reproduced it for the class on a visual
reproduction.
If
our group were to do this over, we would definitely pay more attention to
measurements of chemicals/solutions being added as well as not trying to do
this on the smaller scale we did on the first day trials. Repeating this experiment on a larger scale
using more volume of solutions etc. would give us a better and brighter light
which would hopefully glow longer.
Conclusion
In
conclusion, day two trial was the better of the two days for trials. By utilizing fewer chemicals/solutions and
making those in the larger volumes made for a better, brighter and longer
lasting glow. By adding the stock
solution last, it wasn’t in a weakened state and gave us anything from a bright
flash to that of the 15 second glow.