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Re: Acid Hydrolysis

Postby SciB » Thu Jan 18, 2018 6:50 pm

PLEASE keep ALL your questions about your project in one thread!

If you fail to do that then others may not see the questions and answers that have already been discussed.

I have tried to help you with the formation of phytol from chlorophyll by acid hydrolysis. In my most recent post to your other thread (Jan.12) I suggested that you try adding acetic acid (vinegar) or citric acid to a chlorophyll preparation and looking for a color change. Did you do that?

If you cannot find a specific recipe for a method then you have to experiment and improvise. You know that acid will split phytol from chlorophyll and when this happens the color changes from bright green to olive brown. I suggest that you not try to separate phytol but rather use the plant extract after neutralizing the acid with sodium bicarbonate. If you have pH paper you can use it to see when the solution is neutral, otherwise just add bicarb until it stops bubbling off carbon dioxide.

Sybee

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Re: Acid Hydrolysis

Postby Vlance » Thu Jan 18, 2018 8:26 pm

Ok, next time I will make sure to post to the correct thread, sorry about that. Thank you for the information.
-Vlance

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Re: Acid Hydrolysis

Postby SciB » Thu Jan 18, 2018 9:14 pm

Ok, but the important thing is what are you planning to do? What do you think of my suggestion about using acid-treated chlorophyll without separating phytol? I think you have a really interesting idea for oil-spill remediation and I would like to see you test it. Scientists always have to do preliminary experiments to test their conditions. Just try your chlorophyll prep with and without acid treatment and see what happens. At least then you would have some data.

Sybee

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Re: Acid Hydrolysis

Postby Vlance » Fri Jan 19, 2018 4:27 am

I think you idea provides me with a good solution. So far this is my top choice for separating the Phytol. I do not have to have my data in until March, but the experiment must be performed before that. I will research the bicarbonate sodium to understand more about it and how to get it. Once I figure out how I will get the Phytol out I can start the rest of the project.

Thanks,
Vlance

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Re: Acid Hydrolysis

Postby SciB » Fri Jan 19, 2018 5:44 am

Ok. But I am still advising that you DO NOT try to separate phytol from chlorophyll. Just try it first.

Sodium bicarbonate is a common chemical that you can buy in the grocery store. When you add It to the chlorophyll acid mixture after acid hydrolysis It simply neutralizes the acid. Buy some bicarbonate, add it to some vinegar and you will see what I mean.

Don't wait to start experimenting. Your project has a lot of details that still need to be worked out.

Sybee

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Re: Acid Hydrolysis

Postby Vlance » Fri Jan 19, 2018 2:02 pm

Hi Sybee,
I just wanted to update you that on Tuesday I will actually be testing, your suggested method, to get the Phytol out. Thank you for all of your help! I will update you with my results after the experiment. Also I just wanted to ask you how to use the bicarbonate sodium (I will use baking soda), do I put it on after I use the vinegar or mix it in with the vinegar?

-Vlance

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Re: Acid Hydrolysis

Postby SciB » Fri Jan 19, 2018 2:43 pm

Hi VL,

Glad that you are going ahead. I'm always impatient to see some results!

The purpose of adding the bicarb is to neutralize the acid. So, how do you know how much bicarb to add? The best way is to use pH paper. Are you familiar with that from chemistry? Have you had chemistry? You can get pH paper test strips at Petsmart or Petco or an aquarium supply store and they come with instructions. I think even some Walmart stores have them.

The bicarb (baking soda) is added AFTER the hydrolysis. I don't exactly know how to judge when the hydrolysis reaction is finished, but I would let it go at least one hour at a temperature of 75 F (24 C) or warmer.

When you think the chlorophyll extract has been hydrolyzed, read the pH using the paper strips and add a tsp of bicarb. You should see fizzy bubbles of carbon dioxide (CO2) being given off. That's from the bicarb. Check the pH again. It should be a little higher (neutral is 7.0). Keep adding bicarb and checking the pH until it gets to 7--you're done!

Let me know what happened, ok?

Have a good weekend.

Sybee

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Re: Acid Hydrolysis

Postby Vlance » Tue Jan 23, 2018 1:21 pm

Hi Sybee,
Sorry I was having some technical issues and all my updates are now posted in the post below.

-Vlance
Last edited by Vlance on Tue Jan 23, 2018 2:02 pm, edited 1 time in total.

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Re: Acid Hydrolysis

Postby Vlance » Tue Jan 23, 2018 1:54 pm

Hi Sybee,
Today I did the experiment of trying to separate the phytol. I had 2 viles one with vinegar and chlorophyll and the other with citric acid and chlorophyll. I did not see any obvious results of separation but when I got home I examined the solutions again. I found that the vinegar solution had formed a yellowish green outer layer after about an hour. This is a photo of what I saw, [photo removed by student]. On the top left is the vinegar solution, the top right is the citric acid solution, and the bottom left is the control chlorophyll. After I while I have noticed in the vinegar solution that it started separating. This is a picture of what the separation looks like in the vile, [photo removed by student], and this is what it looks like compared to regular chlorophyll [photo removed by student] (the darker liquid is the chlorophyll, and the lighter liquid is the separated part of the vinegar solution). I was wondering if you could tell me if I had extracted phytol.

-Vlance

Moderator note: I have merged all your posts under your first topic: Oil Spills. As Sybee has told you, please keep all of posts on this project in this topic, otherwise she won't know that you have posted a reply to her very excellent guidance. Thank you!

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby SciB » Wed Jan 24, 2018 6:08 pm

Hi Vlance,

Hmm! If its green, it's still chlorophyll. That means the acid treatment was not strong enough to break the bond between the phytol and the other part of the chlorophyll.

Ask your science teacher if the school has a lab where you could use a strong acid under supervision.

If strong acid is out, there's still one more Plan B--vinegar plus heat. Have you ever boiled green beans too long and had them turn a disgusting khaki color? That's phytol! To heat your chlorophyll I would use a steamer.

You can make a steam generator by putting a pan of water on the stove and bringing it to a boil. Turn down the heat so that it is just simmering and put a glass bowl on top of the pan. The bowl has to be small enough so that the bottom is in the steam but large enough to rest on the lip of the pan. Place some chlorophyll in the bowl and add twice its volume of white vinegar. Take a Before picture. Let it steam for 15 minutes or so and observe the color. Take a picture. If it looks brownish, that's good. If not...well, just try heating it longer.

I just had an idea. You might be able to get phytol by cooking spinach leaves in a pan with vinegar until they turn brownish. All green vegies that I have cooked too long or on too high a heat turned brown, So, instead of making a chlorophyll extract first, cook the leaves first and then make an extract from them. Hey, it's worth a try! Do you like spinach?

Good luck!

Sybee

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby Vlance » Wed Jan 24, 2018 7:58 pm

Hi Sybee,
I am very happy that you came up with another plan to get the phytol out. Do I have to use white vinegar or will any vinegar do? Do I neutralize the phytol and vinegar mixture with baking soda after I take the spinach leaves out? Could I do this part of the experiment by myself or do I need adult supervision? Thank you so much for your help without you this science fair project would have never happened!

-Vlance

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby SciB » Wed Jan 24, 2018 8:49 pm

You are welcome, Vlance! Happy to keep your project on track.

Use only distilled white vinegar because the others (wine, apple cider, balsamic) have fruit esters and other ingredients that might interfere.

So, once you cook your spinach with vinegar, let it cool and check the pH with pH paper. You don't want to add too much baking soda. Add a little and when it stops bubbling, check the pH. Try to get close to pH 7.

Take pictures again and put them on flickr. I want to see nice yukky brown-green phytol!

Sybee

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby Vlance » Thu Jan 25, 2018 1:48 pm

Hi Scybee,
I told my science teacher about making and using a steamer to get the phytol out, but she wanted me to use the already extracted chlorophyll. Would this work the same as the spinach and be as successful? I will either do the steamer experiment today or some time in the next couple of days, and I wanted to make sure that I am choosing the most successful route.

-Vlance

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby SciB » Thu Jan 25, 2018 2:33 pm

Brown, brown--think brown = phytol

No, you can't do the experiment with chlorophyll. Your original procedure calls for phytol and that's what you should use. Just cook some spinach until it turns brown, then do the chlorophyll extraction on that.

The steaming method allows you to control the temperature better--steam by definition is about 212 F. If the leaves stubbornly refuse to turn brown, then just stick them in a pot and keep cooking them until they do. But do take pictures and record what you do carefully in your lab notebook.

Sybee

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Re: Science Fair Project: Cleaning Up Oil Spills

Postby Vlance » Thu Jan 25, 2018 2:36 pm

Hi Sybee,
I now realize I was not very clear about what I was asking. My teacher was wondering if could put the liquid chlorophyll in the steamer and get the phytol out that way. Sorry about the confusion.

-Vlance


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