Pre-reading for Project 3B - from the manual
For the SST-NTU Flagship Programme, we will be working on the Applied Project Challenge 3, and there are a total of 2 parts to this Challenge, Project Part 3A and Project Part 3B. For this blog, we will be keeping the records of what we are doing in the Project Part 3B. For Project Part 3B, we will be working on the extraction of caffeine from tea, which is needed with the help of some techniques. There will be a total of 3 techniques which we are going to use in the extraction of caffeine from tea. However, the most important things which are needed in this project will be the skills in the extraction of caffeine from tea, and also the concepts which are behind these 3 techniques. Here below are some general information about the project, which is extracted from part of the manual for Project Part 3B:
For the SST-NTU Flagship Programme, we will be working on the Applied Project Challenge 3, and there are a total of 2 parts to this Challenge, Project Part 3A and Project Part 3B. For this blog, we will be keeping the records of what we are doing in the Project Part 3B. For Project Part 3B, we will be working on the extraction of caffeine from tea, which is needed with the help of some techniques. There will be a total of 3 techniques which we are going to use in the extraction of caffeine from tea. However, the most important things which are needed in this project will be the skills in the extraction of caffeine from tea, and also the concepts which are behind these 3 techniques. Here below are some general information about the project, which is extracted from part of the manual for Project Part 3B:
The substance which we are going to extract from tea, which is caffeine, is an example of a type of organic weak base called an alkaloid. The term 'alkaloid' means to be 'alkali-like'. Caffeine is a stimulant and is found naturally in tea, coffee and kola nuts. However, caffeine is not the only alkaloid, there are also many other alkaloids such as cocaine (a drug of abuse), strychnine (a poison), morphine (a pain killer), piperine (found in black pepper) and quinine (used to treat malaria and also added to tonic). This clearly shows that some of the alkaloids are beneficial, while others are harmful. In this case, caffeine and piperine are neither beneficial nor harmful, morphine and quinine are beneficial alkaloids, while cocaine and strychnine are harmful alkaloids. So, this is all the general information about caffeine and alkaloids. However, before we conduct the experiment, there is really one question which we need to ask ourselves, and it is: What is the difference between Panadol and Panadaol extra? Researching on this question will really give us a clearer idea on what is an alkaloid, as Panadol is a type of alkaloid.
The main objective of this part of the project is not only to let us try out on how to extract the caffeine from tea, it is also to let us familiarise with the techniques which we are going to use to extract the substance from the tea. In this project, we will learn the skills of how to use 3 different techniques combined together to extract the caffeine from the tea. These techniques are known as Buchner filtration, solvent extraction and distillation under a rotary evaporator. However, do take note that: I am not very sure about whether the 3 different techniques will be combined together to extract the caffeine from tea, or is it that we will be using these 3 different techniques separately to extract the caffeine from tea? I mean, will we be using all the 3 different techniques together in a same experiment to extract the caffeine from tea, or will we be using each technique in each of the experiments to extract the caffeine from tea (One technique used in One experiment, so there will be a total of 3)? I would like to clarify this. If any of you know about this, can you kindly please post a comment under this post? Thank You.
My research on Project Part 3B, especially on the information and pictures about the 3 different techniques, will be on my next post. The above information and pictures is just to give some general information about caffeine and the other alkaloids, and also an introduction to the 3 different techniques. Please do consider and try to answer the question in green, which is: What is the difference between Panadol and Panadaol extra? All of you can choose to answer the question under the comments section, and then we will consolidate all the answers to this question and put them under a new post. Your may also choose to put down your own research into another new post.
Pre-reading for Project 3B - from the net + part of the readings
As mentioned in the previous post, I will research on the 3 different techniques which we are going to use to extract the caffeine from tea. These 3 different techniques are the Buchner filtration, the solvent extraction and distillation under a rotary evaporator. I will also include the pictures about these techniques, and here below is my research on the Buchner filtration and the pictures related to this technique:
For Buchner filtration, when a solid needs to be isolated from a solution, it is normally done at a reduced pressure using a Buchner flask or a Buchner funnel. A Buchner flask is also known as a vacuum flask, but the Buchner funnel is not a vacuum funnel (there is no vacuum funnel at all). The Buchner flask is basically a thick-walled Erlenmeyer flask with a short glass tube and hose barb protruding about an inch from its neck. The function of the glass tube and short barb is to act as an adapter over which the end of a thick-walled flexible hose (tubing) can be fitted to form a connection to the flask. The other end of the hose can be connected to the source of vacuum such as an aspirator, a vacuum pump, or a house vacuum. A Buchner funnel is used together with a Buchner flask, where the Buchner funnel will be fitted through a drilled rubber bung or an elastomer adapter at the neck on top of the flask or the filtration of samples. The function of the vacuum flask is basically to be used as a vacuum trap in a vacuum line to ensure that no fluids are carried over from the source of vacuum (aspirator, vacuum pump or house vacuum) to the evacuated apparatus or vice versa. So, here below is a picture of the vacuum flask. A picture of a Buchner Flask is also shown below. This gives us an idea of how it actually looks like:
2nd picture: http://www.smsols.co.uk/products/vacuum-flask.jpg
Next, for solvent extraction, which is also Part 4.1 of the readings in the Project 3B's manual, we have to take note of the organic and polar solvents and compounds. Most organic compounds are able to dissolve in organic solvents, and most polar compounds / materials such as salts are able to dissolve in polar solvents. Note: When we say a compound is able to dissolve in a solvent, it means the compound is soluble in the solvent OR when mixed with the solvent. Some organic compounds are different because they are able to dissolve more faster and easier in polar solvents than in organic solvents. One of such organic compounds include glucose, and the reason why glucose is more soluble in polar solvents like water than in organic solvents is because it has a large number of polar functional groups such a hydroxyl groups, which is related to the amount of hydrocarbon in it. Larger amount of hydrocarbon, more hydroxyl groups, and more polar functional groups, and hence the compound will also be more soluble in polar solvents. Speaking of water, it is one of the polar solvents. Therefore, we can conclude that - as mentioned or shown in the manual for Project Part 3B:
When we have an organic and a polar compound in a beaker, for example 1,4-dimethoxybenzene (organic) and lithium chloride (polar) as given in the manual, and when we add an organic and a polar solvent each into the same beaker, like diethyl ether (organic) and water (polar), the organic compound which is the 1,4-dimethoxybenzene will dissolve in the diethyl ether (organic compound is soluble in organic solvent), and the polar compound which is the lithium chloride will dissolve in the water (polar compound is soluble in polar solvent). These will form 2 clear layers in the beaker, basically the organic layer and the aqueous layer. The organic layer will contain the mixture of the organic compound and solvent, while the aqueous layer will contain the mixture of the polar compound and solvent. Therefore, the organic layer will contain the 1.4-dimethoxybenzene while the aqueous layer will contain the lithium chloride. Amazingly, it has been discovered that when the organic layer is separated from the aqueous layer, and then dried to remove traces of water before being evaporated, pure 1.4-dimethoxybenzene (which is the organic compound in the first place - so we can say the pure state of the organic compound) will be obtained. This is what we have to look out for in our experiment on caffeine.
Lastly, for distillation using a rotary evaporator, (I will continue with this tomorrow).
Note that our research mainly should focus on caffeine in tea, but I had slightly expanded it by bringing in my research on the three different methods which we are going to use in the experiment of extracting caffeine from tea. Now, the main focus point of my research is on caffeine in tea, and I will put down my research by including some questions which are important to the research - guiding questions.
