Thermospray collisionally induced dissociation with single and multiple mass analyzers

Area of Science:

• Analytical Chemistry
• Mass Spectrometry
• Organic Chemistry

Background:

• Nabilone is a synthetic cannabinoid with potential therapeutic applications.
• Accurate structural determination is crucial for understanding its properties and activity.
• Initial mass spectrometry attempts provided insufficient structural detail.

Purpose of the Study:

• To obtain detailed structural information of nabilone using advanced mass spectrometry techniques.
• To overcome limitations of single-stage collisionally induced dissociation mass spectrometry (CID-MS).
• To elucidate nabilone's structure through fragmentation pattern analysis.

Main Methods:

• Utilized a thermospray discharge ionization source coupled with a triple-stage quadrupole mass spectrometer.
• Employed tandem mass spectrometry (CID-MS-CID-MS) for sequential fragmentation of nabilone ions.
• Analyzed granddaughter ions in the 50-150 Dalton range for structural assignments.

Main Results:

• Single-stage CID-MS yielded limited structural features, with key fragments above 200 Da.
• CID-MS-CID-MS provided lower mass fragments (50-150 Da), enabling confident structure assignments.
• Identified structural features include a branched C9 aliphatic chain, ketonic and ether/alcoholic functionalities, an aromatic ring with phenolic oxygens, and evidence of rings/unsaturation.

Conclusions:

• Tandem mass spectrometry (CID-MS-CID-MS) significantly enhances structural elucidation of complex molecules like nabilone.
• The obtained fragmentation data allows for a reasonable reconstruction of nabilone's possible structures.
• This advanced MS approach provides more comprehensive structural insights than first-order collisional fragmentation alone.