[Sakalas]

Okay, a simple question

What simple ways of indication could be used to indicate these chemical reagents:

~1 mg of Acetaldehyde
~1 microgram of arsenic (if possible)
~3 mg of Isoprene
~30-100 mg of polycyclic aromatic hydrocarbons (Benzo[a]pyrene)

thanks!

[billnotgatez]

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[Arkcon]

Hi there, new person, welcome to the Chemical Forums.  You've already been directed to read the forum rules, and I hope you get a chance to do so shortly.  An important part of the rules is, that our forum isn't a place where people dump complete answers to any old question.  We try to help people learn to help themselves.  So lets begin to work together on that ...

You question isn't one that's easy to answer, and I'm going to start by giving you some hints:

1).  I've moved your question to the Analytical Chemistry sub-forum.  When you want to know What?  and How much? for an unknown sample, the type of chemistry you want is called analytical chemistry.  High school chem labs aren't were I want to go when I want those sorts of questions answered.

2).  You didn't really ask the question the way a chemist would ask it.  Maybe you're new, or maybe we're facing a language barrier.  Not a real problem, but you don't want to "indicate" these reagents, you want to "qualify" and "quantify" them.  It just leaves me wondering, are you ready for the answer if you don't understand the terms?

3).  Detecting these compounds won't be easy, or simple. 

4).  Determining how much is often a separate problem from identity.  You also don't ask for how much the final amount is.  You instead ask in "recipe" amounts, which is a funny way to ask for analytical results.   As though you have a recipe, and you want to know is been followed.  But think about it -- 1 mg, per liter?  per 100 g?  per 1000 metric tons?, in a 10 mg sample?  In a 4 mg sample?  If I told you it was certainly impossible to have so many mg of unknown in a 3 mg sample, you'd just say "Duh, that's less than the sum"  Fine, but what do you mean?

[Sakalas]

Show my attempts of solving the question? Well I am a student, I take part in a biochemistry school.I am doing a project on carcinogens in tobacco(both in raw tobacco and in burned tobacco residue/smoke). I want to use indicative reactions to find these carcinogens and to prove that these kinds of reactions can be used at indentifying toxins and carcinogens in various foods and drugs.
The problem is - I have zero experience in organic chemistry experimentation. I have never performed an organic chemistry experiment. I know that these reagents are quite reactive but I have no clue how much of these reactives I need and how much of the reagent that I would mix with the listed ingredients I would need (for example if it is even possible to do any reaction with 1 microgram (thats how much arsenic it is in 1 pack of cigarettes))

I don't know how else I can show the attempts of me solving this questions, besides showing you my screenshot of my browser history, which is a whole day of googling.

Would it be possible to dissolve cellulose (which is mostly what tobacco comprised of) by leaving the carcinogens intact for indication with other reagents?

[Sakalas]

By "indicating" the reagents I want to prove that this regent is existant in this solution/compound. Sorry about the language barrier, I agree that it exists, I only studied chemistry in Lithuanian and don't really know the exact chemical terms.

[Arkcon]

Hmmm... Ok, interesting.  You have a high school project planned, and you want to analyze a sample, for these components.  The sample in question is tobacco, you want to work with raw tobacco and the inhaled smoked product, and instead of nicotine, burned tars and smoke, you're interested in acetaldehyde, arsenic, Isoprene, and PAH's particularly Benzo[a]pyrene.

You have a lot of work to do.  How are you going to get the smoke into a vessel to analyze it?  Scientists use smoking machines to smoke for them and collect the residue, but you won't have those.

Where did you choose these particular compounds?  Isoprene is a very common hydrocarbon type, you can find it in any plant, even you exhale some without smoking. http://en.wikipedia.org/wiki/Isoprene

Arsenic at a very low level is very difficult to detect.  You will need advanced analytical equipment, the ICP, to detect it.  And a high-schooler won't have access to that either.

Spend some time going over your Google work so far, and try to see if you can write a coherent proposal that addresses some of the questions I've asked you so far.  Then, take that to your teacher.  They'll look at your work, and give you some help with trimming down your question to something possible for you to do.

Best of luck.

And please change your username, I'm sorry if you had some setting up problems, but you're through them now, and wearing your past disappointment on your sleeve isn't really funny or cool.

[Sakalas]

" How are you going to get the smoke into a vessel to analyze it? " Okay, again, excuse my chemical illiteracy/lack of experience in this matter, but why not just burn some ammount of tobacco or why can't I smoke it myself and let the smoke residue into some kind of vessel (im a smoker anyway and the exhaled smoke would benefit my project.)?

"Where did you choose these particular compounds?" http://en.wikipedia.org/wiki/List_of_cigarette_smoke_carcinogens I chose them because there is the biggest ammount of it as stated in the list.

" Then, take that to your teacher." The problem is my chemistry teacher is not working in school at summer so I'm kinda on my own at the moment.

"And please change your username" Will do, as soon as I figure out how to do that.

And thank you for your answers, again I'm terribly sorry for my lack of knowledge in chemistry - while I really like chemistry, I'm just not as good as I wish to be 

[Arkcon]

Well, you can burn it, that's what the smoking robot will do, but it will be hard to "catch" it.  Maybe you can rig up some sort of "water pipe" (no laughing from the peanut gallery please,) drawing smoke from a burning cigarette through a flask of water with some sort of aspiration bulb, and see what analysis you can perform.

No, you can't smoke it.  Scientists in general, and particularly those still in high high school, aren't allowed to experiment on themselves.  I know you may have smoked 5 times a day on your own time, but you can't do it for an experiment.  Its simply not ethical.  It's be like someone made you smoke, extra, for a grade.  Or made a non-smoker start, for an experiment.  Or something.

Good for you, working on a project without the teacher's help.  Keep working, keep reading, and come back if you need more tips.  But you will have to get in touch with your teacher eventually to learn  what you can and can't do.

[billnotgatez]

why can't I smoke it myself and let the smoke residue into some kind of vessel

Even with ethics aside you would be confounding your results.

http://en.wikipedia.org/wiki/Confounding