Application of gas chromatography in the analysis of phytocannabinoids: An update (2020-2023)

INTRODUCTION

Cannabinoids are a group of compounds that bind to cannabinoid receptors. They possess pharmacological properties like that of the plant Cannabis sativa. Gas chromatography (GC) is one of the popular chromatographic techniques that has been routinely used in the analysis of cannabinoids in different matrices.

OBJECTIVE

The article aims to review the literature on the application of GC-based analytical methods for the analysis of phytocannabinoids published during the period from January 2020 to August 2023.

METHODOLOGY

A thorough literature search was conducted using different databases, like Web of Knowledge, PubMed, Google Scholar, and other relevant published materials including published books. The keywords used, in various combinations, with cannabinoids being present in all combinations, in the search were cannabinoids, Cannabis sativa, marijuana, analysis, GC, quantitative, qualitative, and quality control. From the search results, only the publications that incorporate the GC analysis of phytocannabinoids were reviewed, and papers on synthetic cannabinoids were excluded.

RESULTS

Since the publication of the review article on GC analysis of phytocannabinoids in early 2020, several GC-based methods for the analysis of phytocannabinoids have appeared in the literature. While simple 1D GC-mass spectrometry (MS) and GC-flame ionisation detector (FID) methods are still quite common in phytocannabinoids analysis, 2D GC-MS and GC-MS/MS are increasingly becoming popular, as these techniques offer more useful data for identification and quantification of phytocannabinoids in various matrices. The use of automation in sample preparation and the utilisation of mathematical and computational models for optimisation of different protocols have become a norm in phytocannabinoids analysis. Pre-analyses have been found to incorporate different derivatisation techniques and environmentally friendly extraction protocols.

CONCLUSIONS

GC-based analysis of phytocannabinoids, especially using GC-MS, remains one of the most preferred methods for the analysis of these compounds. New derivatisation methods, ionisation techniques, mathematical models, and computational approaches for method optimisation have been introduced.

Geographical Indication Characteristics of Aroma and Phenolic Acids of the Changping Strawberry

Strawberry is the most consumed berry fruit worldwide due to its unique aroma and high nutritive value. This fruit is also an important source of phenolic compounds. Changping strawberries are recognized as a national agricultural product of geographical indication (GI) due to their unique flavor. Widely accepted standards for identifying GI strawberries from non-GI strawberries are currently unavailable. This study compared the aroma and phenolic acid composition of GI and non-GI strawberries. Furthermore, the characteristic aroma and phenolic acid markers of GI strawberries were determined. A classification model based on the markers was established using Fisher discriminant analysis (FDA). In this study, six groups of strawberries with variety name of "Hongyan", including GI strawberries from Changping and non-GI strawberries from Changping, Miyun, Pinggu, Shunyi, and Tongzhou, were collected. A total of 147 volatile substances were discovered using gas chromatography-tandem mass spectrometry. The contents of a few compounds principally responsible for the distinctive aroma in GI strawberries were in the top three of the six groups, providing GI strawberries with a generally pleasant fragrance. OPLS-DA identified isoamyl butyrate and trans-2-octen-1-ol as characteristic markers. Enrichment analysis indicated that beta-oxidation of very long-chain fatty acids, mitochondrial beta-oxidation of very long-chain fatty acids, fatty acid biosynthesis, and butyrate metabolism played critical roles in volatile compound biosynthesis. The total phenolic content was 24.41-36.46 mg/kg of fresh weight. OPLS-DA results revealed that cinnamic acid could be used as a characteristic phenolic acid marker of GI strawberries. Based on the three characteristic markers, FDA was performed on the different groups, which were then divided. The separation of strawberry samples from different origins using the three characteristic markers was found to be feasible. These findings help effectively understand the aroma and phenolic acid composition of strawberries and contribute to the development of strawberries with a pleasant fragrance and health benefits.

Cell Coding Arrays Based on Fluorescent Glycan Nanoparticles for Cell Line Identification and Cell Contamination Evaluation

Cell lines are applied on a large scale in the field of biomedicine, but they are susceptible to issues such as misidentification and cross-contamination. This situation is becoming worse over time due to the rapid growth of the biomedical field, and thus there is an urgent need for a more effective strategy to address the problem. As described herein, a cell coding method is established based on two types of uniform and stable glycan nanoparticles that are synthesized using the graft-copolymerization-induced self-assembly (GISA) method, which further exhibit distinct fluorescent properties due to elaborate modification with fluorescent labeling molecules. The different affinity between each nanoparticle and various cell lines results in clearly distinguishable differences in their endocytosis degrees, thus resulting in distinct characteristic fluorescence intensities. Through flow cytometry measurements, the specific signals of each cell sample can be recorded and turned into a map divided into different regions by statistical processing. Using this sensing array strategy, we have successfully identified six human cell lines, including one normal type and five tumor types. Moreover, cell contamination evaluation of different cell lines with HeLa cells as the contaminant in a semiquantitative analysis has also been successfully achieved. Notably, the whole process of nanoparticle fabrication and fluorescent testing is facile and the results are highly reliable.