Fragbait said:
moecat, why don't you repost all of your results from this extraction (assuming this is the same that was posted and then taken down)? I think those results would generate more disucssion here.
I suppose I can fill in a few details of the other work, although the GCMS data seems sufficient.
The extraction followed the
QT extraction for the most part. Typical acid/base work up, but using pentane to defat and dichloromethane for extraction of the basified phase.
Gas chromatography with flame ionization (FID) detection of the residue gave this chromatogram:
GC-FID chromatogram
HPLC analysis on a C18 column with diode array detection gave:
HPLC chromatogram
The UV spectrum of the component of interest (from the HPLC run) is here:
UV/VIS spectrum
This was very similar to a reference UV/VIS spectrum I found of tryptamine at pH 4:
Tryptamine's UV/VIS spectum
Thus, I felt somewhat confident I had an indole chromaphore in the unknown.
With a desire to ISOLATE the unknown, I ran a reverse phase TLC plate on the residue (note, doing the reverse phase HPLC run pointed to the best solvent system for the reverse phase TLC). Here, the resulting TLC plate is shown under UV light on the right:
Reverse phase TLC
The camera has a hard time picking out the subtle differences in spot color. The unknown of interest was more bluish depending on the angle of the light:
TLC Spots under UV light as 2 different incident angles
My desire to isolate the unknown was due to my desire to obtain a pure sample for infrared spectroscopy. I made up a short flash chromatography column using the TLC solid support. I eluted 30 fractions with what looked like a separation. These are the fractions under UV light:
Preprative chromatography fractions under UV light
This seemed typical of carbolines based on
this paper.
However, repeating the GC-FID analysis on the chromatography fractions showed too poor of a separation for a definitive infrared spectrum of the unknown.
So I said screw it, and answered the question at hand with the GCMS analysis, ...which seems correct.