Recipe for cleaning XAD
with the Soxhlet Extraction Process

Set up the three-part Soxhlet apparatus. You may have several Soxhlets "cooking" at the same time. This depends on the number of burners you have and the capacity of the fume hood. These Soxhlets must be placed within the hood.

Each solvent circulates through the Soxhlet apparatus for 24 hours. After the solvent has bubbled through the thimble for 24 hours, the solvent needs to be changed to a different kind. When the solvents are being changed, every piece of equipment needs to be rinsed out two times. When a skilled lab technician is doing this process, it can take five minutes to change each thimble set-up. So, each change of solvent takes approximately 30 minutes, depending upon the number of set-up thimbles that are cooking and cleaning the XAD.

Here are the steps:

• Set up six Soxhlets (1 day)
  
  
• Then, do the cleaning process. Each of these solvents needs to bubble through the XAD in the set-up thimble for 24 hours.
  1. Methanol
  2. Acetone
  3. Hexane
  4. Dichloromethane
  5. Hexane
  6. Acetone
  7. Methanol
  8. Distilled water (de-ionized)
     
     
• Clean up the apparatus and get it ready for another cycle of washing and cleaning the XAD! (1 day)

The XAD material is now ready to be packed into columns!

So, how long (how many hours or days) will it take Michele and Amy to do this complete cleaning cycle, with six set-up thimbles under the hood? Remember to add in the time it takes them to rinse and clean the set-up thimble apparatus when they change the solvent!