Separation of cannabinoids on three different mixed-mode columns containing carbon/nanodiamond/amine-polymer superficially porous particles

Cannabis: Chemistry, extraction and therapeutic applications

Cannabis, a genus of perennial indigenous plants is well known for its recreational and medicinal activities. Cannabis and its derivatives have potential therapeutic activities to treat epilepsy, anxiety, depression, tumors, cancer, Alzheimer's disease, Parkinson's disease, to name a few. This article reviews some recent literature on the bioactive constituents of Cannabis, commonly known as phytocannabinoids, their interactions with the different cannabinoids and non-cannabinoid receptors as well as the significances of these interactions in treating various diseases and syndromes. The biochemistry of some notable cannabinoids such as tetrahydrocannabinol, cannabidiol, cannabinol, cannabigerol, cannabichromene and their carboxylic acid derivatives is explained in the context of therapeutic activities. The medicinal features of Cannabis-derived terpenes are elucidated for treating several neuro and non-neuro disorders. Different extraction techniques to recover cannabinoids are systematically discussed. Besides the medicinal activities, the traditional and recreational utilities of Cannabis and its derivatives are presented. A brief note on the legalization of Cannabis-derived products is provided. This review provides comprehensive knowledge about the medicinal properties, recreational usage, extraction techniques, legalization and some prospects of cannabinoids and terpenes extracted from Cannabis.

HRMS Detector for the New HILIC CBD Method Development in Hemp Seed Oil

The cannabis analysis has gained new importance worldwide due to the rapid expansion of the hemp global market. Many reverse phase high performance liquid chromatography (HPLC) methods have been developed to analyze cannabidiol (CBD) and its analogues due to the nice fit with their log P values at around 6. However, when CBD was blended with hemp seed oil in consumer, cosmetic, and food industries, the high content of triacylglycerides (TAGs) from hemp seed oil were retained and accumulated inside C₁₈ columns with the common mobile phases and caused a column pressure increase and ghost peaks after continuous sample injections. Coupled with the chemical profile from high resolution mass spectrometry (HRMS) detection, a novel hydrophilic interaction liquid chromatography (HILIC) CBD quantitation method was developed, specifically for CBD blended hemp seed oil materials, which can overcome the matrix buildup in reverse phase columns. The zwitterionic (ZIC)-cHILIC column containing a dense water layer on the stationary phase surface provided a stable partitioning separation mechanism to separate the CBD from TAGs in hemp seed oil. This water layer favors the sustaining NH₄F buffer ions, which can maximize the salting-out action and help reduce the adsorptive interaction between TAGs and stationary phase sulfobetaine materials. The high percentage of acetonitrile (99%) contributed to method sensitivity and reduced instrument maintenance time. The method was developed and validated for the first time. It has been successfully applied to quantify CBD content in hemp seed oil samples, thus demonstrating it to be a useful tool for both quality control and safety assurance in CBD hemp seed oil raw materials and related products.

Potency testing of cannabinoids by liquid and supercritical fluid chromatography: Where we are, what we need

Hemp and cannabis industry is undergoing a renewed interest due to legalization of marijuana (a topic that all countries are discussing, especially in recent years) and the growing importance of therapeutic properties of cannabinoids. Together with an increment in the production of hemp and recreational cannabis, there has been an increasing demand for accurate potency testing of products (i.e. quantification of main cannabinoids present in the plant in terms of weight percentage) prior commercialization. This translates in an urgent need of reliable analytical methods to characterize cannabis and hemp samples. Cannabis and hemp preparations are commercialized under various forms (e.g., flowers, oils, candies or even baked goods) usually containing a large number of often very similar compounds making their separation very challenging. Strictly connected to this, another emerging topic concerns the need for the developing of large scale separation techniques for the purification of cannabinoids from complex matrices and for the preparation of analytical-grade standards (including the chiral ones). This paper reviews the most recent achievements in both these aspects. Cutting-edge applications and novel opportunities in potency testing by high performance liquid chromatography (HPLC) with UV detection (which is becoming the golden standard, according to several pharmacopeias, for this kind of measurements) are discussed. The focus has been given to the very important topic of enantio-discrimination of chiral cannabinoids, for which supercritical fluid chromatography (SFC) appears to be particularly suitable. The last part of the work covers the purification of cannabinoids through preparative chromatography. In this regard, particular attention has been given to the most innovative multi-column techniques allowing for the continuous purification of target molecules. The most recent advancements and future challenges in this field are discussed.

Recent advances and applications of synthetic diamonds in solid-phase extraction and high-performance liquid chromatography

Since the advent of diamond-based adsorbents in the late 1960s, the interest in their use for solid-phase extraction (SPE) and high-performance liquid chromatography (HPLC) has steadily increased. This is primarily due to their unique properties, such as extreme chemical and thermal stability, high mechanical strength and biocompatibility, and complex mixed-mode retention mechanisms. Currently, the most commonly used synthetic diamonds in SPE and HPLC are detonation nanodiamonds (DND), high-pressure high-temperature (HPHT) diamonds, and chemical vapour deposition (CVD) diamonds. These diamonds have been either used as individual particles (in both modified and unmodified forms), or for surface modification, or entrapped within composites and core-shell particles to develop new diamond-based adsorbents. These diamond-based adsorbents have been used for a variety of applications, including streamlined proteome analysis; extraction of anions, cations, actinides, uranium, lanthanides, alkaline earth metals, transition metals, and post-transition metals; and development of reversed-phase, normal phase, hydrophilic interaction, ion chromatography, and mixed-mode liquid chromatography columns, to name but a few. These varied applications of different types of diamonds are typically governed by their specific properties. This review discusses the various surface and bulk properties of DND, HPHT diamonds, and CVD diamonds that facilitate or limit their use in different SPE and HPLC based applications.

Cannabis Sativa L.: a comprehensive review on the analytical methodologies for cannabinoids and terpenes characterization

The global Cannabis Sativa market, including essential oils, foods, personal-care products, and medical formulations has gained much attention over the last years due to the favorable regulatory framework. Undoubtedly, the enormous interest about cannabis cultivation mainly derives from the well-known pharmacological properties of cannabinoids and terpenes biosynthesized by the plants. In this review, the most recently used analytical methodologies for detecting both cannabinoids and terpenes are described. Well-established and innovative extraction protocols, and chromatographic separations, such as GC and HPLC, are reviewed highlighting their respective advantages and drawbacks. Lastly, GC × GC techniques are also reported for accurate identification and quantification of terpenes in complex cannabis matrices.

Chromatographic characterisation of 11 phytocannabinoids: Quantitative and fit-to-purpose performance as a function of extra-column variance

INTRODUCTION

Cannabis sativa L. (cannabis) is utilised as a therapeutic and recreational drug. With the legalisation of cannabis in many countries and the anticipated regulation of potency that will accompany legalisation, analytical testing facilities will require a broadly applicable, quantitative, high throughput method to meet increased demand. Current analytical methods for the biologically active components of cannabis (phytocannabinoids) suffer from low throughput and/or an incomplete complement of relevant phytocannabinoids.

OBJECTIVE

To develop a rapid, quantitative and broadly applicable liquid chromatography-tandem mass spectrometry analytical method for 11 phytocannabinoids in cannabis with acidic and neutral character.

METHODOLOGY

Bulk diffusion coefficients were calculated using the Taylor-Aris open tubular method, with four reference compounds used to validate the experimental set-up. Three columns were quantitatively evaluated using van Deemter plots and fit-to-purpose performance metrics. Low (1.2 μL² ) and standard (3.6 μL² ) extra-column variance ultra-high pressure liquid chromatography (UPLC) configurations were contrasted. Method performance was demonstrated with methanolic cannabis flower extracts.

RESULTS

Bulk diffusion coefficients and van Deemter plots for 11 phytocannabinoids are reported. The developed chromatographic method includes the challenging Δ⁸ /Δ⁹ -tetrahydrocannabinol isobars and, at 6.5 min, is faster than existing methods targeting similar panels of biologically active phytocannabinoids.

CONCLUSIONS

The bulk diffusion coefficients and van Deemter curves informed the development of a rapid quantitative method and will facilitate potential expansion to include additional compounds, including synthetic cannabinoids. The developed method can be implemented with low or standard extra-column variance UPLC configurations.