In this aspirin course work I will be investigating different types of aspirin and making aspirin. I will be looking at all the process taken to make aspirin and all the ingredients in aspirin.I Will be:Extracting some salicylic acid (2-hyroxy benzoic acid) from willow twigs or bark.OCOHOH2- hydroxy benzoic acid structureWe will also be learning about TLC (thin layer chromatograph), and its uses to confirm the identity of compounds. Calculating percentage yield carrying out melting points.My assignment will be structured into four tasks:Task 1- a survey of aspirin containing medicines and the medical uses of aspirin.Task 2-extracting and identifying the active chemical in willow barkTask 3- comparing methods for making and purifying aspirinTask 4- analysingTask 1- a survey of aspirin containing medicines uses of aspirinName of aspirinAdult/childrenPriceDoseIngredientsContra-indicatorsAscriptinChildren over the age of 12ï¿½11.492 caplets every 4 hours while symptoms persist, not to exceed 12 caplets in 24 hours, or as directed by a doctor for arthritis therapy.
Drink a full glass of water with each dose.Aluminum Hydroxide Dried Gel (80mg), Calcium Carbonate, Magnesium Hydroxide (80mg), Aspirin (500 mg)Do not use if taking a prescription drug for anticoagulation (blood thinning), diabetes, gout, or arthritis unless directed by a doctor. Antacids may interact with certain prescription drugs. If you are presently taking a prescription drug, do not take this product without checking with your doctor or other health professional.Alka-seltzer plus12 and overï¿½4.87Take 2 tablets fully dissolved in water for every 4 hoursAcetaminophen 250mg (Pain Reliever/Fever Reducer), Chlorpheniramine Maleate 2mg (Antihistamine), Phenylephrine HCI 5 mg (Nasal Decongestant)Do not use if you are allergic to aspirin this product if you are on a sodium restricted diet unless directed by a doctorAnacin12 and overï¿½5.792 tablets every 6 hours do not exceed 8 capsules in 24 hoursAspirinDo not use if you have ever had an allergic reaction to any other pain reliever/fever reducer.BayerAdults and children over the of 12ï¿½6.
49Take 1 or 2 tablets with water every 4 hours. Do not exceed 12 tablets in 24 hours unless directed by a doctor.Aspirin 325mgDo not take this product if you are taking a prescription drug for anticoagulation (thinning the blood), diabetes, gout or arthritis unless directed by a doctor.AspergumAdults and children over the age of 12ï¿½3.49Chew 2 tablets every 4 hours, not to exceed 16 tablets in 24 hours, or as directed by a doctor.Aspirin (227 mg (3.5 gr))Do not take this product if you are taking a prescription drug for anticoagulation (thinning the blood), diabetes, gout, or arthritis unless directed by a doctor.Task 2- Extraction and identification of the active chemical from willow barkIn this practical we have to extract some salicylic acid from willow bark.
We had to reflux it, which allows you to heat it for a long time period without losing any liquids.Then we have to use thin layer chromatography to help us to confirm its identity.Apparatus* Reflux apparatus* 250cm3 beaker* 2 dropping tubes or melting-point tubs* Sulphuric acid* Potassium manganate* Iodine crystals* Willow twigs or bark* Coffee grinderWe do not have access to a batch reactor that is used in factories to make aspirin so the pear shaped flask would act as the batch reactor. This is were all of the reacting will take place.Method* Take a sample of fresh twigs or bark from a willow tree and chop them into fine pieces using a coffee grinder.
* Set up a flask with a reflux condenser. In the flask place some of the fresh twigs or bark.* Cover the twigs with a mixture containing equal volumes of 2moldm-3 sulphuric acid and 0.
2moldm-3 potassium manganate solution.* Reflux for 15 minuets.* While the mixture is still warm pour the mixture into a 25ocm3 beaker. It is not important if some bark comes with it. Carefully add further portions of a mixture of 2moldm-3 sulphuric acid and 2moldm-3 potassium manganate solution. With stirring until the volume is three times bigger.
You must take great caution in handling the apparatus because it is extremely hot.Thin layer chromatography (TLC)Chromatography can be used to separate a mixture of components. Both qualitative and quantitative data can be obtained.
Modern high performance techniques can identify trace impurities in samples. Chromatography can also be used to separate mixtures on a large scale. There is a range of related techniques.
All work on the same principle. A delivery system supplies a mobile phase, which is moved through a stationary phase. The mobile phase, which is usually a solvent, carries the substance being analysed through the stationary phase. This is called elietion. A stationary phase often consists of a liquid system is used to monitor the separated components. A component is attracted to both mobile and stationery phases.
The relative strength of attraction for each phase is important. A component strongly attracted to the stationary phase will be held back one strongly attracted to the mobile phase will pass through rapidly. Separated is achieved when components have different relative attractions for the two phases.ChromatographyMobile phaseStationary phaseThin-layerLiquid solventAl2 03 or Si 02 (often bounded together with CaSo3 and supported on a plastic sheet or glass plate this is called a TLC plate)PaperLiquid solventH20 can the surface of absorbent chromatography paper and therefore support by the cellulose fibres in paper)Gas layerInter gas (usually N2 or Ar )Liquid often a silicone gum (supported on suitable solid particles in a glass or metal tube)High performance liquidLiquid solventSmall solid particles (packed tightly in a tube usually stainless steel)When identifying the components some of them will be coloured and so will be visible but often they will not be visible. So then there are a lot of techniques that’s can used to see them:* Specially pre-treated plates when exposed to ultraviolet light reveal substances as pale purple spots.
Be careful not to look at the light for too long.* Exposure of plates to develops e.g.
iodine vapour of chemical reagents which are sprayed on the plate after separation.* Radioactive isotopes can be used as tracers be careful when using radioactive isotopes. X-ray film is placed over the palate for a period of time. The positions of the components show up as dark spots when the film is developed.
The degree of darkness indicates the amount of radiation and therefore the concentration of the component.MethodApparatus* Small beaker* T.l.c plates* Clingfilm or lid* Methanol* U.
v lamp* Glass tube* Salicylic acid in ethanol* Take a piece of pre-dried thin-layer chromatography sheet, which will fit, into a small beaker. Dissolve a small quantity of the substance to be investigated in a solvent.* Draw a base line using a graphite pencil on the palate. It should be just above the level that will be reached by the solvent in the beaker. Apply the solution the palate using a finely drawn out glass tube.* The spot formed by the solution should be as small as possible.
This is because components that do not separate well, will tend to overlap if large spots are made.* Put the solvent in the beaker and cover it with cling film or a lid. Leave for 10 minutes to allow the atmosphere to saturate. Stand the plate in the beaker and replace the lid.* When the solvent front is near the top of the plate remove the plate. Mark the position of the solvent front.
Set up for the thin layer chromatographyChromatographypaper lidSolvent frontBaselinebeakersolventPure 2 hydroxy benzoic acid my sample of purified 2 hydroxy benzoicAcidTask 3- comparing methods for making and purifying aspirinOCOOH COH OHOC+ (CH3 CO) 2O +CH3 COOH CH3Salicylic acid ethanoic anhydride acetylsalicylic acid (vinegar)(2-hydroxbenzoic acid) (Aspirin)Method 1Apparatus* 2-hydroxybenzoic acid* 100ml beaker* Ethanoic anhydride* Concentrated sulphuric acid* Distilled water* 250ml beaker* Vacuum filtration equipment (buchiner funnels, buchiner flasks, tubes andFilter paper)* Ethanol* Melting point apparatusBuchner funnel setupWeigh 5.0g of 2-hydroxybenzoic acid in a 100ml beaker. Add 10ml of ethanoic anhydride with care stir to dissolve the solid. Add 12 drops of concentrated sulphuric acid stir continuously to prevent charring. Cool the mixture to room temperature and add it to 150 ml of distilled water to a 250 ml beaker.Filter the solid produced under vacuum filtration, wash with 50ml of distilled water. Re-crystallise the solid using a 50:50, which means equal quantities of distilled water and ethanoic acid as a solvent say about 10mls each. Filter, dry the product and take the melting points then store the products.
We then had to work out the percentage yield and theoretical yield.Sample 1Theoretical yield(Maximum yield possible) = 138g 180g1g 1801385g 1805138Theoretical = 6.52Percentage yield= Actual yield 100Theoretical yield= 0.32 1006.52= 4.91gMethod 2Apparatus* Quickfit flask* 2-hydroxybenzoic acid* Phosphoric acid* Reflux apparatus* Distilled water* 250ml beaker* Glass rod* Ice* Vacuum filtration equipment* Melting point apparatus* Test tubeAdd the following to a 100ml quickfit flask 50.
0g of 2-hyroxybenzoic acid and 10ml of ethanoic anhydride. Then add 12 drops of 85% phosphoric acid and swirl to mix. Fits a reflux condenser heat the mixture for about 10 minutes in a water bath without cooling add 5ml of water down the condenser. When the vigorous reaction has ended pour the mixture into a 100ml of cold water in a 250ml beaker.Cool to room temperature. Stir and rub the sides of the beaker with a glass rod to start crystallisation.
Stand the beaker in an ice bath to complete the crystallisation process. Filter under a vacuum wash with a little water. Re-crystallise the solid from hot water dry the product in a drying cabinet weight the product record its melting point. Calculate the yield and store the product in a labelled test tube.
For each of the samples we made we had to use tlc to identify any impurities in our products. To do the tlc we needed 250ml beaker with Clingfilm or a lid, 5-10mls of solvent which is ethyl ethanoate mixed with a few drops of ethanoic acid. We had to spot the tlc plate with the following pure aspirin, 2-hydroxybenzoic acid, make the solvent front, remove from the beaker and dry. We then had to look at the plate with a uv lamp and mark out the position of the spots.Sample 2Percentage yield= Actual yield 100Theoretical yield= 3.34 1006.52= 51.
2gResultsProduct 1Product 2Weight0.323.34Melting point125172Tlc0.850.
90Task 4- analysing aspirinRF (relative to the front) valuesThe distance a component moves relative to the solvent front is called its RF value.The equation is RF=distance moved by componentDistance moved by solvent frontSolvent frontchromatography paperBaselinePure sampleMy sampleUse a ruler to measure the length from the baseline to A then from the baseline to the solvent front then do the same for the other sample.Task2 results for TLCRF= 3.8 =0.5 my sample8.4RF=4.3 =0.5 pure sample8.
4The sample that I made is pure compared to the pure sample that we testedTask3 method 1Solvent front= 8.2 cmPure aspirin=7.1cmMethod 1= 7.0cmMethod 2= 7.
4cm2-hydrcxybenzoic acid= 6.4cmRF= 7.08.2 = 0.85 method 1RF= 7.48.
2 = 0.89 method 2RF= 7.1 = 0.85 pure aspirin8.2RF= 7.48.2 =0.
77 2-hydroxybenzoic acidProblemsSome of the problems that I encountered are not filtering the samples properly so when I took it out it was still mushy, so what I did to correct that was I had to put it into an oven for it to dry out. Or I could have filtered it again. Another problem that I had was when I was filtering my products the vacuum didn’t have enough pressure for it to work that way it wouldn’t of got filtered properly. So what I had to do to correct that problem is I had to open the tap as far as I could push the buchiner funnel into the flask and push in the tubes so that way there would be more pressure.Interpretation of the resultsThe thin layer chromatography (TLC) results tell me that my 2-hydrography benzoic acid (Salicylic acid) that I produced is not pure. Some of the reasons could be:* There were same impurities* Some of it didn’t get converted properly* I did something wrong in the preparationMy first sample gave me a pure sample compared to the pure aspirin I tested.
My second product wasn’t pure I think this was because there were some impurities in the product or I did something wrong in the preparation.My method 1 gave me a very small yield maybe it was because we did something wrong or maybe there were was some impurities in it. I could see all of the crystals in the product. And my product was bright white.My method 2 gave me a very large yield but for some reason it was discoloured and it was light pink. I also couldn’t see any crystals.My results (TLC, melting points) tell me about my 2 products that the product 1 has a small yield therefore the yield is more pure.
Were as my product 2 has a big yield so the yield is not that pure. My results also tells me that maybe the reason why my product 2’s boiling point was so high because the impurities that were in it had I high melting point. My results tell me that if you want pure aspirin in small batches you should use method 1, but if you want a lot of aspirin but not that pure you should use method 2. but I think that method 1 is the best method because you don’t need to heat it up for that long and the sample is pure.EvaluationThe literature value of aspirin is 1350C my sample for method 1 had a melting point of 1250C, which is quite close to the literature value, but it is not the same.
Maybe this is because there were some impurities in my product or I did something wrong in the preparation stages.My sample for method 2 had a melting point of 1720C, which is very far from the literature value of aspirin this is mainly because there were some impurities in my sample making the melting point higher.Comparison with industrial processes of aspirin productionIn a factory were they make aspirin some of the processes that require precision, strength, time or knowledge are not done by humans they are done by machines or computers.
The processes that are replaced by automation are:* The equipment and chemicals are transported on conveyor belts* Computers control the temperature* All of the processes that are done over night are done by computers* All of the filtration processes are done by computers* Controlling the batch reactor* PurificationSome of the advantages of using machines and computers to do most of the work is:* They are more precise* More accurate than humans* They work none stop* They are more cheaper* They are more stronger* Faster* More accurate* No errors* More durable