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Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: cisz on September 22, 2016, 05:57:47 AM

Title: use of ninhydrin
Post by: cisz on September 22, 2016, 05:57:47 AM

I ran a reaction using urea, imidazole, and n-acetyl cysteine using a microwave oven to produce n-acetyl cysteine amide.

I did tlc using urea, imidazole, NAC, and NAC amide (product as spots.

From what I've read I thought that ninhydrin would be able to make visible spots on tlc plates but, so far, on heating with a heat gun the only spot appearing is the NAC.

Help appreciated.

Title: Re: use of ninhydrin
Post by: AWK on September 22, 2016, 06:21:55 AM

https://books.google.pl/books?id=fBCDK_Tgh10C&pg=PA531&lpg=PA531&dq=TLC+NH4HSO4&source=bl&ots=5kn5e3RVUm&sig=-m_Nd7QVH9mD0b2GoB7JQqaCAoU&hl=pl&sa=X&ved=0ahUKEwifj-Gz36LPAhXKuBQKHZjxD24Q6AEIHzAA#v=onepage&q=TLC%20NH4HSO4&f=false
Try spray reagent 3 or 4 (heating on hot plate)

Title: Re: use of ninhydrin
Post by: Babcock_Hall on September 23, 2016, 10:19:36 AM

I am surprised that ninhydrin was successful, but I have been surprised before.  There is a TLC spray based on Ellman's reagent, which will detect thiol groups.

Title: Re: use of ninhydrin
Post by: cisz on September 24, 2016, 08:07:56 AM

Vanillin?

Quote from: AWK on September 22, 2016, 06:21:55 AM

https://books.google.pl/books?id=fBCDK_Tgh10C&pg=PA531&lpg=PA531&dq=TLC+NH4HSO4&source=bl&ots=5kn5e3RVUm&sig=-m_Nd7QVH9mD0b2GoB7JQqaCAoU&hl=pl&sa=X&ved=0ahUKEwifj-Gz36LPAhXKuBQKHZjxD24Q6AEIHzAA#v=onepage&q=TLC%20NH4HSO4&f=false
Try spray reagent 3 or 4 (heating on hot plate)