Question

You work for an anti-drug doping agency. You recieve a syringe with contents chemically similar to the banned substance clenbuterol, but does not show up on current drug screens.

QUESTION. Using your knowledge of chemistry and mass spectrometry outline an experimental plan that could be used to extract and analyse the residue via mass spectrometry and obtain information on the molecular weight and formula of the alleged new drug. Make sure to explain your reasoning for each step and discuss if you would need to use more than one form of mass spectrometry to get a firm answer.

Answer 1

Since the unknown drug is chemically similar to clenbuterol, it might have the same functional groups but molecular weights will be different if not optical isomers of clenbuterol. Assuming that it is not optical isomer and sticking to mass spectrometry as mentioned in the question. I will use GC-MS to deduce its molecular weight. First I would run the known sample of

Clenbuterol and get its GC-MS Spectra and then run the unknown sample. On conmparing the Spectra it will clearly show if these are different compound or same.

Then on analysing the mass Spectra and comparing with the mass library the unknown sample can be identified if present in the library. If it's not present then need to carry out manual analysis based on literature reports and Chemistry knowledge and fragmentation pattern of mass spectroscopy. This will give the idea of the molecular weight and formula.

CONFIRMATION - To confirm with 100% assurity ,after identifying the compound, that commercial available compound can be bought and run in GC-MS to confirm the Spectra or else if the compound is not commercially available then the unknown sample can be run in HRMS and confirm it's Molecular weight.