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Mass spectra of harmaloids

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burnt

burnt

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SWIM was recently informed of recent controversy surrounding authenticity of FV's THH. Therefore SWIM will post some mass spectral data on harmine, harmaline, and THH. This can help others who have acquired data to compare their data with SWIMs data.

Note that all these spectra were acquired via GC-MS using an ion trap mass spectrometer. Also note that all spectra matched a commercial data base. Harmine and harmaline were extracted and analyzed from peganum harmala. THH was synthesized via reduction of harmaline and harmine.

The reason there are 3 photos for each spectra is to zoom in one some minor ions.

If someone else who has mass spectra data on the actual sample in question FV's THH please post or post a link so SWIM can compare.

In the near future SWIM will analyze FV's material versus a reference THH and see what it really is.
 
burnt: Can you give like a short tutorial of how to read this ?
Click to expand...

Well what you are seeing in each picture are ions with a particular mass to charge (m\z) ratio which corresponds to their mass. MS works by ionizing molecules and then scanning a mass range. In this case molecules are bombarded with electrons until an electron gets removed when this happens the molecule becomes positively charged. When this happens the molecule usually becomes unstable and fragments into pieces. So what you are seeing is the fragmentation pattern. Think of it like a fingerprint for a molecule.

For example:

Harmine the mass is 212.25 So one ion signal is 212.2 which corresponds to what is called the molecular ion. In this case it is quite large but some compounds the molecular ion is very unstable and hard to see. Since its the biggest signal in this spectrum its also known as the base peak. The base peak is usually characteristic of particular molecule. In other words its usually a reproducible signal even in different instruments.

The ion with a mass of 197.2 would correspond to harmine minus a methyl group because a methyl group weighs 15 atomic mass units (amu) so 212-15=197. There are 2 methyl groups on the harmine molecular and its very hard to determine which one fell off. You can use radioactive isotopes to do this or whats called MS/MS and re-fragment that particular ion but that's way more advanced and not necessary. Its also quite common to get M+1 or M-1 peaks which are plus or minus one hydrogen atom being attached to or removed from the molecular ion.

212-169 = 43. I don't know what this would correspond to exactly but you could do some playing around with the masses of fragments and the logic of how this molecule would fall apart to figure out what that ion is. This is actually quite difficult to do and is something mass analysts spend a lot of time learning.

Another important number is the ion count. The total ion count is shown at the top. The ion count (its not an exact number but usually a number multiplied by 100 or a million i don't know in this case) for each fragment is shown below the mass number. This number is useful for calculating the ratio of each fragment to one another. This ratio is useful for further identify confirmation and is often incorporated into commercial databases to give the computer another searching parameter.
 
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