Analysis of isomeric cannabinoids standards and Cannabis products by GC-MS, GCxGC-qMS and UPLC coupled to Ion Mobility Mass Spectrometry (TWIM-MS)
Name: NAYARA ARAUJO DOS SANTOS
Type: MSc dissertation
Publication date: 15/02/2018
Advisor:
Name |
Role |
|---|---|
| WANDERSON ROMÃO | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| BONIEK GONTIJO VAZ | Co advisor * |
| RAFAEL SCORSATTO ORTIZ | External Examiner * |
| RICARDO MACHADO KUSTER | Internal Examiner * |
| WANDERSON ROMÃO | Advisor * |
Summary: Cannabis sativa L. plant, popularly known as marijuana, is considered a complex matrix due to its many constituents, among them more than 100 are classified as cannabinoids. These compounds are distributed in the plant in different isomeric forms, which hinders the unambiguous characterization of the psychoactive compounds. Therefore, the present study reported the analysis of seven cannabinoid standards (five neutral: Δ9-THC, CBD, CBC, CBN and CBG, and two cannabinoid acid standards: Δ9-THCA A and CBDA), as well as Cannabis products (hashish and marijuana) and parts of the Cannabis plant (flower and leaf) using four different analytical techniques, mono and two-dimensional gas chromatography (GC-MS and GCxGC-qMS), Ultra performance liquid chromatography coupled to mass spectrometry (UPLC-ESI(±)TOF-MS) and ion mobility spectrometry (UPLC-ESI(±)-TWIM MS). The results obtained by GC-MS demonstrated extremely close retention times (Δt=1.303 min) in the five cannabinoids analyzed from the use of a non-polar stationary phase, DB5. However, GCxGC-qMS resulted in a better distinction in the identification of cannabinoids constitutional isomers, WHERE four of eleven cannabinoids were detected in the three samples; hashish, flower and Cannabis leaf. The analysis, by UPLC-ESI(±)TOF-MS, of marijuana and hashish samples, allowed the identification of eight isomers in the XIC mode at m/z 315.2354. In the analyzes by UPLC-ESI(-)TWIM MS, a large number of compounds was mainly detected for hashish and flower samples. As for cannabinoids of m/z 357, ten peaks could be detected, equally distributed, in flower and hashish chromatograms. Although GC is one of the most used techniques in the study of cannabinoids in Cannabis and its products, it does not allow the identification of acid cannabinoids, which are widely available in the plant, without previous laborious preparatory stages. Differently, liquid chromatography combined with ion mobility mass spectrometry, allowed the identification of both types of cannabinoids (acids and neutrals), in addition to providing a greater detection of constitutional isomers compounds compared to classical GC technique.
