Advion provides integrated laboratory solutions for comprehensive cannabis testing including potency determination, cannabinoid levels analysis, pesticide identification, and quantitation of heavy metals. Advion’s custom cannabis laboratory solutions include the expression Compact Mass Spectrometer (CMS), modular AVANT (U)HPLC systems, and SOLATION ICP-MS.
Streamline your workflow by integrating the Advion Plate Express™ TLC Plate Reader and Advion Atmospheric Solids Analysis Probe (ASAP®) for cannabis sampling solutions. Get direct, rapid analysis of your samples to determinate the level of various cannabinoids – such as the naturally occurring cannabinol (CBN), tetrahydrocannabinol (THC) (i.e. the psychoactive ingredient of cannabis sativa), and the degradation product cannabidiol (CBD) without additional sample preparation.
Figure 1. Chemical structures, elemental compositions, and molecular masses of select Cannabinoids.
Application: Using TLC/CMS for Cannabis Analysis
The Advion Plate Express TLC Plate Reader provides a rapid, push-button analysis of a TLC plate by transporting the targeted compounds directly into the CMS. Determination of the active components of cannabis are required for law enforcement, where these compounds are illegal, and for product control and optimization in the increasing number of legal markets.
In scenarios that require simple, unequivocal, and legally defensible methods for the detection and quantification of plant metabolites, the detector of choice is inevitably mass spectrometry.
Figure 2. Experimental set up of the CMS and Plate Express.
Methods using the TLC/CMS for qualitative detection of cannabinoids, as well as HPLC/CMS for the quantitative determination of THC all herald the added benefits of using compact mass spectrometry in the analysis of cannabis.
The Plate Express can analyze, either singly or sequentially, a lane on a TLC plate. This is followed by the extraction of the compounds present, and then transporting them to the CMS for further analysis. Figure 3 depicts a TLC/CMS analysis of THC in a typically qualitative manner, with the resulting negative ion mode in-source CID MS (Figure 3C) in the unequivocal determination of THC present in this sample (simultaneously acquired positive ion mode MS and in-source CID MS data not shown).
TLC/MS analysis of cannabinoids. (A) A typical TLC separation of an analytical mixture of CBD, CBN, and THC at 1 μg material on the lane. (B) TLC/MS analysis of the Rf region of THC (Rf=0.47) shows a strong MS TIC signal with a prominent negative ion signal at m/z 313.2 (data not shown). (C) The characteristic in-source CID fragments of THC. (D) An alternative approach analyzing the whole TLC lane shows that CBN, CBD and THC are not baseline separated during TLC analysis, so quantitative analysis should use HPLC/MS.
Figure 3. TLC/MS analysis of cannabinoids.
However, both THC and CBD not only have the same isotopic mass (despite having a different molecular structure), but also fragment identically in positive ion mode ESI/MS (data not shown, compare). However, when it comes to negative ion mode, in-source CID results in the same m/z fragments, but at markedly different relative intensities. Thus, this allows for differentiation between THC and CBD in negative ion mode MS.
(A) A typical HPLC/CMS chromatogram for all three analytes in negative ion mode SRM with the upper trace being the XIC of m/z 313.2 and the lower trace XIC of m/z 309.2. Good linearity calibration functions can be obtained for all three compounds (B: THC, C: CBD and D: CBN) covering a range from 250 to 2.5 ng analyte on the 2.1 mm ID column used – sufficient to analyze plant material with as little as 0.1% w/w THC content.
Figure 4. LC/MS analysis of cannabinoids.
Further, an HPLC/CMS method was set-up to demonstrate a quantitative workflow, aiding in the detection of CBN, CBD, and THC based on SIM scanning within a 10-min separation time and detection in negative ion mode (see Figure 4A). Calibration functions with good linearity in a range of 2.5 to 250 ng on column (i.e. sufficient to quantify from cannabis plant material with only 0.1% w/w content such as roots, stems and leaves of the plant) can be observed from the triplicate analysis of cannabinoid standards.
Application: Using ASAP/CMS for Cannabis Analysis
It is possible to use the Advion ASAP combined with atmospheric pressure chemical ionization (APCI) on the CMS to conduct direct sample analysis for rapid screening and quality control. This technique facilitates the direct and rapid investigation (in less than 30 seconds) of any material that is suspected of containing THC/Cannabinoids. What’s more, the process doesn’t involve the need for any sample preparation.
Figure 5. ASAP with extended glass capillary directly inserted into the ASAP-enabled APCI ion source of the CMS.
Figure 6. Schematic of ASAP/APCI/CMS analysis.
Ergonomically designed for workflow efficiency, the ASAP has a push-button grip and release to quickly pick up glass capillaries for fast assays. The ASAP with the sample is inserted directly into the ASAP-enabled APCI ion source of the CMS to provide sensitive analysis with no sample preparation or chromatography.
Figure 7. To simulate skin contact with Cannabis material as it would occur when e.g. rolling a cigarette or handling raw material, a pinch of the sample was rolled between the thumb and forefinger.
Figure 8. MS data showing both positive ionization (top trace) and negative ionization (bottom trace) of the ASAP finger skin analysis before and after cannabis exposure of the control skin (left) and exposed skin (right).
A pinch of the known cannabis material was rolled between the thumb and forefinger. The index finger was then swiped with the ASAP probe for analysis (Figure 3). It was observed that in comparison to a control skin sample, an abundant signal is visible on the exposed skin at m/z 311.2/309.1 and 315.2/313.2, consistent with the respective (M+H)+ and (M–H)— of THC/CBD and Cannabinol (Figure 4).
Interestingly, it was noted that only the combined positive and negative ion mode data can provide a reliable confirmation for the presence of cannabinoids, since an ordinary skin sample usually shows a variety of signals across the mass range (data not shown).
- The Advion expression CMS significantly enhances the quality of information obtained from natural products – thus aiding in the quality control of cannabis sativa-based products as well as law enforcement
- The CMS, equipped with faster scan speed, on-line polarity switching, and in-source CID, generates valuable information in cannabis analysis
- The Advion Plate Express TLC Plate Reader generates targeted mass spectra using thin layer chromatography plates, thus analyzing spots of interest
- The Advion ASAP requires no sample preparation and no chromatography for rapid, direct analysis of any solid or liquid sample
- HPLC/CMS provides a robust and reliable quantification method for THC, CBN, and CBD
Recommended Methods for the Identification and Analysis of Cannabis and Cannabis Products’ United Nations Office on Drugs and Crime 2009; ISBN 978-92-1-148242-3
Broecker S, Pragst F. Isomerization of cannabidiol and Δ9-tetrahydrocannabinol during positive electrospray ionization. In-source hydrogen/deuterium exchange experiments by flow injection hybrid quadrupole-time-of-flight mass spectrometry. Rapid Communication in Mass Spectrometry 2012; 26(12):1407-1414. We would like to acknowledge Sigma-Aldrich Supelco for the generous gift of the Titan HPLC column used in this study.
This information has been sourced, reviewed and adapted from materials provided by Advion.
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