I am an A-level chemistry student and have recently started my individual investigation. For this I am comparing the methods that can be used to determine the purity of various samples of aspirin. I have chosen thin layer chromatography as one of my methods and was wondering if there was any information availably on this subject.

I find it strange that an A level student would expect information from this forum. To me an A level student would know how to research this on their own. With the ease of information gathering from the internet, people have forgotten how to use libraries.

Well John, I am sorry that you feel that way but I see the internet as a valuable source of information and is often far better than libraries, especially the one at my sixth form college which does not offer the specialised information that is required to do my A level individual investigation. I hoped that this forum would offer me some assistance but I now know that it is obviously for stuffy old farts that have nothing better to do with their time than send rude replies to less-knowledgeable people who were asking a simple question. Perhaps it is because you cannot offer me the information because you do not know it all, as you imagine you do. I urge you to get a life!

Dear Kate,

Go to Google.com and do a search for aspirin and thin layer chromatography and you will have lots of hits and methods to use.

Stahl's book on TLC will have lots of information.

Dr. Joseph Sherma's book on TLC is another excellent source of information.

Good luck from an old fart.

Rodney

Kate: My point is an A student should already understand how to search with google by themself. My 8 year old can do this... must be colleges have watered down their grades.

I have to agree with John. You have to do your own work. There is a big difference between getting stuck then asking for help and just expecting someone else to do your work for you. None of us believes that we know everything; however, we do know how to use a library or search engine. We may be old farts, but you are a spoiled brat.

I think everyone's getting a little carried away here. No need for name calling and if you don't think a request is reasonable or legitimate, don't respond to it. Many people might think the kid is clever going right to the experts. And Kate, some of us are young farts and some are just farts.

I totally agree with jclark !!!!!!

We don't we try to be just a technics who wants to share knowledge ?.

KAF

I think Kate is being resourceful. Anyway, they do not teach IT correctly at school. You only learn how to use it properly when you get to University.

I have been on various sides of this issue and from that perspective I would like to add some thoughts to this discussion.

1. My compliments to Kate for using her name in this communication. Furthermore, the request was politely worded and sufficiently detailed. These attributes would have resulted in my having more interest in helping (if I knew anything about the topic)than otherwise might have been the case.

2. Often, perhaps most often, an industrial lab supporting the manufacture of some chemical uses a method that is superior to anything in the literature.

3. Most literature describing an analysis is out of date or flawed. It is difficult for someone not experienced in a technique to judge the utility of a literature method.

4. As a result of 2&3 "The literature" is my last resort for finding out how to analyze something. Most preferred- a contact at a company that makes or uses the stuff to be analyzed. Next- instrument company or supplier that might sell to a customer that does the analysis. Next-could be this forum if its participants are helpful. Last- slug it out in the literaure and be prepared to discover methods that do not work.

5. The lazy, or resourcesful, approach described in 4. makes the most sense for anyone needing to get the job done efficiently and reliably. I insisted my apprentices use it.

6. Students are not in catagory 5. Ultimately they need to be successful in analyzing something, but they need to learn how to find a method in the literature, how to judge its worthiness, learn that everything they read, especially on the Internet, may not be reliable, etc. They also need to know that practicing chemists, forums and suppliers have useful information, too. I am not sure about what is the proper level of help this forum should provide a student, but we should offer some help/encouragement to the worthy, see 7. And, the level of help could be different if kate was at Indiana or a tiny college. (many PhD candidates come from small schools)

7. If you happened to interview students lately maybe you discovered there aren't as many A students going to graduate school. On the high school level, 1/2 of the AP chemistry programs in our ACS section have been eliminated for lack of interest. We don't need to discourage chemistry students.

8. Kate, these are stressful times to be a chemist-layoffs, budget cuts, reduced help, tuition bills for children due. It can make one cranky at times. ( PS. Look in the ASTM books and Pharmacopeia(sp?this isn't my area) and see if they have methods for aspirin purity. What you find may be out of date by 20 years or more, but what you find will be reliable)

9. Does anyone other than organic chemists do TLC anymore? Hint, you won't find the answer in the literature, but you might find the answer on this forum.

I would just like to thank everyone for their participation in this discussion. I have never heard of Google.com as in my school we are only taught how to turn on a computer, not how to surf the web efficiently. John, I hope I didn't offend you but I was getting very stressed out about my coursework as we were expected to hand in an equipment list after only two days of being issued the task. I was disappointed that no one with any helpful information had responded as I had no luck looking elsewhere, including the library. I have now handed in the list, although I still fell a bit dubious about the effectiveness of the method I have chosen. Now all I have to do is carry out the thin layer chromatography, along with colorimetry and a titration, analyse it all and make a conclusion all in a matter of a few weeks. The English schooling system leaves a lot to be desired, far too much is expected of us! No wonder so many A level students have committed suicide! Thank you all once again, I very much appreciate it!

Obviously there are many opinions about the purpose of this forum.

I feel that one should have done some research or trials before asking a broad spectrum question. Show me that you have made some effort and I will gladly offer my ideas to get you in the right direction (if I can). Learning is about mistakes, and I have made many.

I apologize to Kate and hope you do well with your project.

I think you are right to ask your questions Kate because if you can't ask the experts, who can you ask?! Im afraid i cant help you myself but i wish you luck and i think that the people who called you a spoiled brat should look at themselves for once: they are obviously spoiled too as they aren't prepared to share their knowledge with those in need. If they won't do this then what is the point in them being part of this forum?!
Goodluck Kate

Kudos to Bill Tindall for his thoughtful and eloquent contribution. One additional suggestion for Kate: citing a bit more detail about the investigations you had already done might have helped you avoid triggering negative reactions from some readers. Most people are happy to help students who clearly have made efforts to solve problems on their own, but there seem to be many postings from students who appear to be looking for a handout rather than a helping hand, and forum readers are clearly getting tired of those.

I hope your project turns out well, and that you have found your experience with this forum valuable.

Kate,
In my opinion a little ground work was expected from you. This would have helped in seeking guidance from the experts. hope you have the required info by now. Aspirin the wonder drug of the century should be very easy for u to get info.

Kate,

I hope that it all goes well for you. I am a practicing industrial chemist, and my first port of call these days is also the internet. I use the literature too, but only once I have distilled enough info from the various on line databases. I agree with your comments on the state of UK education.

Hi, Im in the same situation as Kate but slightly diffent, I've finished my coursework and am analysing my data and was wondering if any one knows where i could find data sheets for
TLC of Amino acids, so far ive only managed to find 4
Glutamic Acid, Histidine, Tryptophan, Valine,
Does Anyone know anywhere i could get this information as i live in a small village with a very limited library, Cheers Jon

Hi everyone, long time no see.
My chemistry cousework is going swimmingly at the moment. My TLC has worked and shown that the aspirin I made was pure, as has the melting point experiment and the titration. Now all I have to do is do a bit of colorimetry and analyse the results. If only I didn't have French coursework to do at the same time!

Well I work for a pharmacuticle firm and we test paracetamol etc by T.L.C , G.C, L.C as well as the obvious wet chemistry methods, if your testing by TLC depending on what is in the product you may need to spray the plates, but for most paracetamol plates you use a standard paracetamol, a standard potassium sorbate for exampleor what ever else is in the sample, and then place in a solvent system (of either 90 :10 Chloroform : Methanol solution) and view under uv 254nm to check th rf values !
Hope that could've been of some help !

Hello Everyone,
Just thought I'd let you all know that I got a B in my A level chemistry exam and that I am now at Cardiff University studying Pharmacy. It's a 4 year masters degree, with a year of pre-registration training after that. I absolutely love it here and my course is really interesting. Once I've qualified I'm hoping to do a pHd and maybe go into lecturing and research.

Kate