[trying to understand]

Hi,  I am hoping someone could offer some assistance with a chemistry lab I am doing.  It is comparing the absorbency of organic contaminants of cotton/cellulose to that  of charcoal.   We started with two cotton balls that were treated with NaOH for 15 minutes, then rinsed, and then treated them with cyanuric chloride for one hour. We washed them with acetone and then water and dried via vacuum filtration.  Then we treated the cotton balls with 100 mL piperazine for thirty minutes in a flask, rinsed, and then dried in vacuum filtration.  We also had to dilute an atrazine analog solution(red dye), and determine its wavelength maximum using a digital spectrophotometer.  The red dye was 1ppm which we diluted to 1 part dye to 10 parts water.  I think we need to determine the wavelength maximum for the charcoal that we have.  We have three different sizes powdered, F300, and F400. How would I go about testing charcoal and cotton balls in a spectrophotometer?  Or is that not possible?  I am wondering what would be the best approach for determining the absorbency of atrazine analog for each.  I just really don't know how to conduct this experiment at all.  I really want to understand the steps necessary to conduct this experiment and understand the results.  I've spent too long confused.  Any help that you can offer would be more appreciated than you know.

Sincerely,
A mom who decided to go back to school

[ARGOS++]

Dear Trying to understand,

If I only realised the half of all you explained, I have to tell you, that this experiments will not work the way you have in mind.

There is "absolute" no possibility to measure charcoal or cotton balls (balls or not balls) in a conventional UV/Vis-Spectrometer.
The only way to come to relevant data is in my opinion, if you go the indirect way, there are different names for it.
I try to describe the recipe with “your dye”, if I got the problem correctly from your description:

 1.  )  Prepare your dye solution, and determine its concentration by measuring it with the spectrometer (maybe at λ_max).
 2a.) Insert your cotton ball (if possible a dry one) and keep it for the reaction time.
 3a.) After the time remove the cotton ball and measure the dye solution once again.
 4a.) The difference between both measurements gives you the absorbed amount on cotton.

 2b.) Add the amount of charcoal to the dye solution for the declared reaction time.
 3b.) Now separate the charcoal from the dye solution by using a centrifuge.
 4b.) Measure the concentration of the over standing dye solution in the spectrometer again.
 5b.) Do the equivalent calculation as under 4a.).

I hope I have drawn the Idea clear enough for you, and that I have understood your problem.

I hope this may bee of some help to you!

Good Luck!
                    ARGOS⁺⁺