MSACL 2018 US Abstract

Topic: Cannabinoids

Analysis of Cannabis-Related Samples for Composition via LC-MS Employing a Compact Mass Spectrometer

Jack Henion (Presenter)
Advion, Inc

Bio: Professor Jack Henion is Emeritus Professor of Toxicology at Cornell University where he was a member of the College of Veterinary Medicine commencing in 1976. Dr. Henion was co-founder of Advion BioSciences in 1993 and is now CSO of Advion, Inc. and VP R&D of Q2 Solutions, a Joint Venture between Quintiles and Quest. Professor Henion has received three Doctor Honoris Causa (Honorary Doctorate) degrees in recognition of his international reputation in modern analytical techniques. During his tenure at Cornell Professor Henion conducted research and explored applications in many areas of liquid chromatography/mass spectrometry (LC/MS) employing atmospheric pressure ionization (API) sources. Professor Henion has published over 225 peer reviewed papers in the scientific literature, and trained nearly 100 students, post-doctoral scientists, and trainees.

Authorship: Jack Henion, Ben Nie, Nigel Sousou, Changtong Hao, and Simon Prosser,
Advion Inc. 10 Brown Rd, Ithaca, NY 14850, USA

Short Abstract

The analyses of cannabis-related plant materials and products are being performed using techniques ranging from the very simple, unsophisticated ‘tests’ to highly selective, very expensive analytical approaches. This presentation will describe an approach which uses generally accepted analytical methods, as well as a technique that uses a compact mass spectrometer equipped for LC/MS, to assure accuracy and precision for the qualitative and quantitative determination of potency and pesticides in cannabis-related samples. A comparison of LC/UV coupled in-line with selected ion monitoring (SIM/MS) will be shown for both potency and pesticide measurements from plant materials.

Long Abstract

Introduction

Screening of complex sample matrices using GC/FID or HPLC/UV was commonly used in the past, but in the modern, well-equipped laboratories, more sensitive and more importantly, more selective detection technologies are employed. Highly selective detectors include electron capture (ECD) with GC for highly electronegative compounds or fluorescence with HPLC if target compounds contain fluorophores. In the absence of these ‘chemical handles’ for detection, a chemical component may either not be detected at all, or obscured under another chemical entity that co-elutes at the same retention time. The best way to mitigate the occurrence of this missed information is to use a more selective, broad-based detector. These days a mass spectrometer generally serves this purpose quite well.

Chemical screening analyses by mass spectrometry are considered among the ‘gold standards’ for samples with complex chemical composition. This includes determining the level of important expected constituents like THC, CBD, CBN, THCA, etc. as well as possible toxins such as pesticides, etc. The current rapidly growing aspects of the cannabis industry raises many medical, legal, social and analytical questions. Due to the chemically complex nature of representative samples including the presence of isobaric cannabis analogs, chromatography coupled with sensitive and selective detectors is often beneficial.

Although high-performance triple quadrupoles, QTOF’s and orbitraps are ‘in vogue’ for these applications, this presentation will describe how often some important questions can be quickly answered by simpler, less sophisticated approaches. In this presentation, we will describe how the determination of cannabis-related compounds and pesticides may be performed utilizing a novel compact mass spectrometer coupled to ultra-high-performance liquid chromatography (UHPLC) or even thin layer chromatography (TLC). Comparison of results with SRM LC/MS will also be shown.

The described compact, transportable single quadrupole mass spectrometer may be coupled with sophisticated on-line UHPLC sample analysis (UHPLC/MS) or with simple TLC plates (TLC/MS) following a preliminary sample cleanup. Utilization of a QuEChERS (quick, easy, cheap, effective, rugged and safe) extraction procedure allows for the removal of unwanted matrix components and provides relatively clean extracts for analysis by LC/MS.

Methods

Authentic cannabis plant materials confiscated by the Philadelphia, PA police were prepared for LC/MS/MS and LC/MS analysis in a DEA-licensed laboratory by extraction using the QuEChERS technique employing the sample preparation kit from UCT (Bristol, PA). In addition, hemp plant material, grown at Cornell University in trial plots, were prepared in the same manner using the QuEChERS sample preparation technique in the laboratory of Advion, Inc. which is not yet a DEA-licensed laboratory. Currently NYS is only approved for medicinal marijuana use, not for recreational use. However, hemp plant material with a THC content of less than 0.3% by weight can be legally handled and analyzed in our non DEA-licensed laboratory. Since hemp differs primarily from marijuana only with respect to the level of THC, we have commenced our cannabis plant studies using hemp plant materials.

The initial results to be shown will compare analysis of the same cannabis plant extracts with both LC/MS/MS as well as LC/MS using the compact mass spectrometer. Quantitative determination for both potency of four major cannabinoids as well as eleven common pesticides will be shown as comparisons. Next, recent studies of hemp extracts with a renewed focus on optimal sample preparation using both QuEChERS as well as liquid-liquid extraction and SPE will be described with a focus on the appearance of both the LC/UV trace as well as the LC SIM/MS ion current profiles. Importantly, negative control hemp plant material will be used as a matrix-matched sample set including fortified standards of the target cannabinoids, quality control (QC) samples and the stable isotope internal standards (SIL’s) for the cannabinoids will be used for a more rigorous quantitative analysis protocol.

In a similar manner, control hemp plant material will be fortified with known levels of certain pesticides for their quantitative determination also using matrix-matched standards, QC’s and SIL’s. Quantitative determination of the selected pesticides will be made by SIM LC/MS using the same compact single quadrupole mass spectrometer system.

Results

The results for cannabis potency were comparable for both LC/MS/MS and LC/MS analysis of the authentic cannabis extracts. Thus, the quantitative results were the same for both systems suggesting that perhaps potency determination for cannabis does not necessarily require LC/MS/MS techniques. Due to the relatively high concentration of cannabinoids in the marijuana plant significant dilution can be performed making the analysis easily within the detection capabilities of both the triple quadrupole as well as the single quadrupole mass spectrometer systems.

Following these results a systematic study for optimizing the analysis of hemp extracts was undertaken. This included optimized sample preparation and analysis for potency of targeted cannabinoids as well as a panel of common pesticides. It is important to note the contrast in normal levels of cannabinoids in marijuana plant materials vs. the potentially much lower levels of pesticides which may be present on the plants. High levels of cannabinoids are much easier to measure and may not require the sensitivity of LC/MS/MS. However, natural plant materials contain hundreds of chemicals which may require relatively high selectivity in order to distinguish between targeted compounds and endogenous components. That was the focus of these studies and the reason for including a UV detector with four different, simultaneous wavelengths in-line with the mass spectrometer.

The results of these studies revealed that there can be chemical interferences in an LC/UV chromatogram that co-elute and thus adversely bias (elevate) our quantitative determinations. Details for both potency and pesticide measurements will be shown and compared.

Conclusions & Discussion

The development of optimized simple, routine and economical LC/MS methods for the multi-residue quantitative determination of cannabinoids and pesticides in cannabis plant extracts was possible using the compact single quadrupole mass spectrometer. This approach provides the opportunity for rigorous, high-quality analytical methodology which can deliver performance rigor which includes high sensitivity coupled with much greater selectivity than other, more conventional detectors. The performance of this analytical approach should be suitable for regulatory compliance as these controls are implemented. This presentation will underscore the importance of high-quality analytical chemistry techniques which include duplicate matrix-matched standards, the use of stable isotope internal standards when available, quality control (QC) samples and defined acceptance criteria. The cannabis industry can benefit from the proven LC/MS methods of GLP regulated bioanalysis as well as the standard operating procedures (SOP’s) of anti-doping and forensic urine drug testing laboratories.


References & Acknowledgements:

1. J. H. Liu and M.P. Fitzgerald, Mass Spectrometric characterization of cannabinoids in raw cannabis sativa l. Samples, Anal. Chem., 1979, 11, 1875-1877.

Acknowledgements

Danielle Mackowsky, Brian Kinsella and Mike Telepchak, United Chemical Technologies, 2731 Bartram Rd, Bristol, PA 19007, USA


Financial Disclosure

DescriptionY/NSource
Grantsno
SalaryyesSalary from Advion, Inc.
Board MemberyesSMRTL
Stockno
Expensesno

IP Royalty: no

Planning to mention or discuss specific products or technology of the company(ies) listed above:

yes