Analgesics
Picture of Three Plates

March 7, 2003
 
Materials Needed
  • Samples of three different types of analgesics
  • Glass pipet(prepared in class)
  • Glacial acetic acid
  • 1,2-dichloromethane
  • 95% ethanol
  • acetone
  • mixed "hexanes"
  • ethyl acetate
  • acetic acid
  • three thin layer plates impregnated with silica gel
  • UV lamp
  • 3-500mL beakers(used as developers)

Procedures

  • pulverize sample to a fine powder with the back  of laboratory spoon
  • prepare a glass pipet  by warming the pipet and stretch when it is soft,  break  the pipet to create  to small tipped pipets.
  • took a small amount of the powdered  analgesic and place it in a beaker 
  • mixed powered analgesic (aleve) with a small amount of 95% ethanol and swabbed a small amount on the tip of the glass pipet
  • placed swabbed pipet at the bottom of three large silica plates and dotted with a pencil to indicate where it was placed. 
  • swabbed two other analgesics (aspirin and ibuprofen) and caffeine with the glass pipet and dotted it on the silica plate
  • Also dotted with a pencil to indicate where products had been placed
  • Prepared three following mixtures:

        a) 1:12 (acetic acid: 1,2-dichloroethane) in mL

       b) 25:1 (ethanol: acetyl acetone) in mL         

       c) 5:1:1:2 (1,2-dichloroethane: acetone: ethanol: mixed hexanes) in mL

  • Placed silica plates in each of the mixtures and allowed them to rise until 1/8 in. of tip
  • Allowed to dry and placed all three silica plates under ultraviolet (UV) light and circled where the color had moved.
  • Placed all three silica plates in an iodine bath and let sit for 10 minutes.
  • After soaking in iodine bath we then circled the stains where each color (analgesic) had moved.

Observations:

  • Take a look at connecting page for our Rf values
  • All three mixtures were clear (like water) and gave off a strong aroma
  • After iodine bath our lead was the only analgesic bound by the iodine.
  • Caffeine dot hardly moved at all.

 

DEVELOPMENT
plate.jpg

PLATE UNDER UV LAMP
uv.jpg

Hugo Tapia
Terese Marie Nuņez
Rachel Sierra