Why does acetaminophen (Ac) have two spots on the TLC plate? ?

I spotted five compounds on a silica gel TLC plate and used 95% ethyl acetate: 5% acetic acid for the mobile phase solvent. The five compounds spotted are acetaminophen (Ac), aspirin (As), unknown (U), ibuprofen (I), and naproxen (N). 

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1 Answer

  • 1 month ago

    My first guess is that the acetaminophen is old and that some of it has undergone hydrolysis, removing the acetyl group. 

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