Analysis of cannabinoids in oral fluid by liquid chromatography–tandem mass spectrometry

Development and validation of a method for analysis of 25 cannabinoids in oral fluid and exhaled breath condensate

Currently, there is a significant demand in forensic toxicology for biomarkers of cannabis exposure that, unlike ∆9-tetrahydrocannabinol, can reliably indicate time and frequency of use, be sampled with relative ease, and correlate with impairment. Oral fluid (OF) and exhaled breath condensate (EBC) are alternative, non-invasive sample matrices that hold promise for identifying cannabis exposure biomarkers. OF, produced by salivary glands, is increasingly utilized in drug screening due to its non-invasive collection and is being explored as an alternative matrix for cannabinoid analysis. EBC is an aqueous specimen consisting of condensed water vapor containing water-soluble volatile and non-volatile components present in exhaled breath. Despite potential advantages, there are no reports on the use of EBC for cannabinoid detection. This study developed a supported liquid extraction approach and LC-QqQ-MS dMRM analytical method for quantification of 25 major and minor cannabinoids and metabolites in OF and EBC. The method was validated according to the ANSI/ASB 036 standard and other published guidelines. LOQ ranged from 0.5 to 6.0 ng/mL for all cannabinoids in both matrices. Recoveries for most analytes were 60-90%, with generally higher values for EBC compared to OF. Matrix effects were observed with some cannabinoids, with effects mitigated by use of matrix-matched calibration. Bias and precision were within ± 25%. Method applicability was demonstrated by analyzing ten authentic OF and EBC samples, with positive detections of multiple analytes in both matrices. The method will facilitate comprehensive analysis of cannabinoids in non-invasive sample matrices for the development of reliable cannabis exposure biomarkers.

Recent Advanced Methods for Extracting and Analyzing Cannabinoids from Cannabis-Infused Edibles and Detecting Hemp-Derived Contaminants in Food (2013-2023): A Comprehensive Review

Cannabis-infused edibles are food products infused with a cannabis extract. These edibles include baked goods, candies, and beverages, offering an alternative way to consume cannabis instead of smoking or vaporizing it. Ensuring the accurate detection of cannabis-infused edibles and identification of any contaminants is crucial for public health and safety. This is particularly important for compliance with legal regulations as these substances can have significant psychoactive effects, especially on unsuspecting consumers such as children or individuals with certain medical conditions. Using efficient extraction methods can greatly improve detection accuracy, ensuring that the concentration of cannabinoids in edibles is measured correctly and adheres to dosage guidelines and legal limits. This review comprehensively examines the preparation and extraction techniques for cannabinoid edibles. It covers methods such as solid-phase extraction, enhanced matrix removal-lipid, QuEChERS, dissolution and dispersion techniques, liquid-phase extraction, and other emerging methodologies along with analytical techniques for cannabinoid analysis. The main analytical techniques employed for the determination of cannabinoids include liquid chromatography (LC), gas chromatography (GC), direct analysis in real time (DART), and mass spectrometry (MS). The application of these extraction and analytical techniques is further demonstrated through their use in analyzing specific edible samples, including oils, candies, beverages, solid coffee and tea, snacks, pet food, and contaminated products.

Detection of Cannabinoids in Oral Fluid Specimens as the Preferred Biological Matrix for a Point-of-Care Biosensor Diagnostic Device

An increasing number of countries have started to decriminalize or legalize the consumption of cannabis for recreational and medical purposes. The active ingredients in cannabis, termed cannabinoids, affect multiple functions in the human body, including coordination, motor skills, memory, response time to external stimuli, and even judgment. Cannabinoids are a unique class of terpeno-phenolic compounds, with 120 molecules discovered so far. There are certain situations when people under the influence of cannabis may be a risk to themselves or the public safety. Over the past two decades, there has been a growing research interest in detecting cannabinoids from various biological matrices. There is a need to develop a rapid, accurate, and reliable method of detecting cannabinoids in oral fluid as it can reveal the recent intake in comparison with urine specimens, which only show a history of consumption. Significant improvements are continuously made in the analytical formats of various technologies, mainly concerning improving their sensitivity, miniaturization, and making them more user-friendly. Additionally, sample collection and pretreatment have been extensively studied, and specific devices for collecting oral fluid specimens have been perfected to allow rapid and effective sample collection. This review presents the recent findings regarding the use of oral fluid specimens as the preferred biological matrix for cannabinoid detection in a point-of-care biosensor diagnostic device. A critical review is presented, discussing the findings from a collection of review and research articles, as well as publicly available data from companies that manufacture oral fluid screening devices. Firstly, the various conventional methods used to detect cannabinoids in biological matrices are presented. Secondly, the detection of cannabinoids using point-of-care biosensors is discussed, emphasizing oral fluid specimens. This review presents the current pressing technological challenges and highlights the gaps where new technological solutions can be implemented.

Determination of cannabinoids in human cerumen samples by use of UPLC-MS/MS as a potential biomarker for drug use

A quantitative analytical procedure was developed and validated by the use of Ultra- Performance Liquid Chromatography tandem Mass Spectrometry (UPLC-MS/MS) for the determination of Cannabidiol (CBD), Cannabinol (CBN), Δ⁹-Tetrahydrocannabinol (Δ⁹-THC), Cannabichromene (CBC), Cannabigerol (CBG) and 11-Nor- 9- Carboxy- Tetrahydrocannabinol (THC-COOH) in an unconventional biological matrix, cerumen. All the investigated calibration curves were characterized by high correlation values (R² ≥ 0.9965). The LODs and LOQs ranged from 0.004 to 0.009 μg g^-1 and 0.012-0.029 μg g^-1, respectively. Intra-assay and inter-assay precision were found to be 0.6-2.5%, and 0.8-2.2%, respectively. All recovery values of cannabinoids, with the use of the optimum cotton swab, at low (0.008 μg g^-1 of cerumen), medium (0.037 μg g^-1of cerumen) and high (0.16 μg g^-1 of cerumen) control levels, were estimated to be above 86%. The method developed here permitted the analysis of real cerumen samples obtained from fourteen cannabis users. In twelve out of fourteen cases, Δ⁹-THC was found to be positive, while in six cases, three major cannabinoids, CBN, CBG and Δ⁹-THC were quantified at concentrations 0.02-0.21 μg g^-1, 0.01-0.24 μg g^-1 and 0.01-4.86 μg g^-1, respectively. Subject #8 has the highest amount of the detected substances in both left and right ear, with Δ⁹-THC at a concentration of 1.85 and 4.86 μg g^-1, CBG 0.06 and 0.24 μg g^-1, CBN 0.10 and 0.21 μg g^-1, respectively. In addition, a detection window for the substances Δ⁹-Tetrahydrocannabinol, Cannabinol and Cannabigerol, in cerumen, was defined with success. In this case, Δ⁹-THC reached a maximum detection frame of up to fifteen days after smoking 0.5 g of marijuana cigarette. ANOVA-one-way analysis also indicated that the average earwax production of non-cannabis users differs significantly from the one of cannabis users (p = 0.048, <0.05). On the other hand, no significant difference was noticed between male and female users as the p value exceeded 0.05. In addition, no significant effect was observed on earwax production in regard to age, frequency and the last time of use (p > 0.05). These last three factors proved to have a significant impact on cannabinoids concentrations, since p values were less than 0.05.

A systematic review of quantitative analysis of cannabinoids in oral fluid

Cannabis sativa L. is a substance widely used around the world for recreational and medicinal purposes. Oral fluid has been investigated as an alternative biological matrix for demonstrating the illegal use of cannabis, particularly in situations where its recent use needs to be identified. In the last two decades, many methods have been developed to detect and quantify cannabinoids in oral fluid, especially for Δ⁹ -tetrahydrocannabinol, the primary psychoactive substance of cannabis. However, some aspects must be considered in the use of these techniques, such as cannabinoids recoveries or extraction efficiency from different oral fluid collection devices/containers. Pharmacokinetic studies have shown that the presence of minor cannabinoids and metabolites in the analysis of oral fluid may be valuable in interpreting tests, which indicates the need to improve the sensitivity of detecting low concentrations. The aim of this review is to summarize and to describe the methodologies for the quantitative analysis of cannabinoids in oral fluid that have previously been investigated. A systematic search for articles was performed of four different databases, using the descriptor "cannabinoids and oral fluid". Forty-seven studies that examined quantitative methods were identified. The analytical data described in these articles, including oral fluid collection, sample preparation, cannabinoids recovery and extraction efficiency, detection instruments, and quantification limits, were analyzed. The discussion of these particular features of cannabinoid analysis in oral fluid could help to improve or to develop methods for use in Forensic Toxicology.

Analysis of cannabinoids in conventional and alternative biological matrices by liquid chromatography: Applications and challenges

Cannabis is by far the most widely abused illicit drug globe wide. The analysis of its main psychoactive components in conventional and non-conventional biological matrices has recently gained a great attention in forensic toxicology. Literature states that its abuse causes neurocognitive impairment in the domains of attention and memory, possible macrostructural brain alterations and abnormalities of neural functioning. This suggests the necessity for the development of a sensitive and a reliable analytical method for the detection and quantification of cannabinoids in human biological specimens. In this review, we focus on a number of analytical methods that have, so far, been developed and validated, with particular attention to the new "golden standard" method of forensic analysis, liquid chromatography mass spectrometry or tandem mass spectrometry. In addition, this review provides an overview of the effective and selective methods used for the extraction and isolation of cannabinoids from (i) conventional matrices, such as blood, urine and oral fluid and (ii) alternative biological matrices, such as hair, cerumen and meconium.

A review on the recent advances in HPLC, UHPLC and UPLC analyses of naturally occurring cannabinoids (2010-2019)

INTRODUCTION

Organic molecules that bind to cannabinoid receptors are called cannabinoids, and they have similar pharmacological properties like the plant, Cannabis sativa L. Hyphenated liquid chromatography (LC), incorporating high-performance liquid chromatography (HPLC) and ultra-performance liquid chromatography (UPLC, also known as ultrahigh-performance liquid chromatography, UHPLC), usually coupled to an ultraviolet (UV), UV-photodiode array (PDA) or mass spectrometry (MS) detector, has become a popular analytical tool for the analysis of naturally occurring cannabinoids in various matrices.

OBJECTIVE

To review literature on the use of various LC-based analytical methods for the analysis of naturally occurring cannabinoids published since 2010.

METHODOLOGY

A comprehensive literature search was performed utilising several databases, like Web of Knowledge, PubMed and 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 Cannabis, hemp, cannabinoids, Cannabis sativa, marijuana, analysis, HPLC, UHPLC, UPLC, quantitative, qualitative and quality control.

RESULTS

Since 2010, several LC methods for the analysis of naturally occurring cannabinoids have been reported. While simple HPLC-UV or HPLC-UV-PDA-based methods were common in cannabinoids analysis, HPLC-MS, HPLC-MS/MS, UPLC (or UHPLC)-UV-PDA, UPLC (or UHPLC)-MS and UPLC (or UHPLC)-MS/MS, were also used frequently. Applications of mathematical and computational models for optimisation of different protocols were observed, and pre-analyses included various environmentally friendly extraction protocols.

CONCLUSIONS

LC-based analysis of naturally occurring cannabinoids has dominated the cannabinoids analysis during the last 10 years, and UPLC and UHPLC methods have been shown to be superior to conventional HPLC methods.

Oral Fluid Drug Testing: Analytical Approaches, Issues and Interpretation of Results

With advances in analytical technology and new research informing result interpretation, oral fluid (OF) testing has gained acceptance over the past decades as an alternative biological matrix for detecting drugs in forensic and clinical settings. OF testing offers simple, rapid, non-invasive, observed specimen collection. This article offers a review of the scientific literature covering analytical methods and interpretation published over the past two decades for amphetamines, cannabis, cocaine, opioids, and benzodiazepines. Several analytical methods have been published for individual drug classes and, increasingly, for multiple drug classes. The method of OF collection can have a significant impact on the resultant drug concentration. Drug concentrations for amphetamines, cannabis, cocaine, opioids, and benzodiazepines are reviewed in the context of the dosing condition and the collection method. Time of last detection is evaluated against several agencies' cutoffs, including the proposed Substance Abuse and Mental Health Services Administration, European Workplace Drug Testing Society and Driving Under the Influence of Drugs, Alcohol and Medicines cutoffs. A significant correlation was frequently observed between matrices (i.e., between OF and plasma or blood concentrations); however, high intra-subject and inter-subject variability precludes prediction of blood concentrations from OF concentrations. This article will assist individuals in understanding the relative merits and limitations of various methods of OF collection, analysis and interpretation.

Validation of a liquid chromatography-tandem mass spectrometry method for analyzing cannabinoids in oral fluid

A liquid chromatography tandem mass spectrometry method was developed for quantifying ten cannabinoids in oral fluid (OF). This method utilizes OF collected by the Quantisal™ device and concurrently quantifies cannabinol (CBN), cannabidiol (CBD), Δ9-tetrahydrocannabinol (THC), 11-hydroxy-Δ9-THC (11-OH-THC), 11-nor-9-carboxy-Δ9-THC (THC-COOH), 11-nor-9-carboxy-Δ9-THC glucuronide (THC-COOH-gluc), Δ9-THC glucuronide (THC-gluc), cannabigerol (CBG), tetrahydrocannabiverin (THCV), and Δ9-tetrahydrocannabinolic acid A (THCA-A). Solid phase extraction was optimized using Oasis Prime HLB 30 mg 96-well plates. Cannabinoids were separated by liquid chromatography over a BEH C18 column and detected by a Waters TQ-S micro tandem mass spectrometer. The lower limits of quantification (LLOQ) were 0.4 ng/mL for CBN, CBD, THC, 11-OH-THC, THC-gluc, and THCV; and 1.0 ng/mL for THC-COOH, THC-COOH-gluc, CBG and THCA-A. Linear ranges extended to 2000 ng/mL for THC and 200 ng/mL for all other analytes. Inter-day analytical bias and imprecision at three levels of quality control (QC) was within ±15%. Mean extraction efficiencies ranged from 26.0-98.8%. Applicability of this method was tested using samples collected from individuals randomly assigned to smoke either a joint containing <0.1%, 5.9%, or 13.4% THC content. This method was able to identify and calculate the concentration of 6 of 10 cannabinoids validated in this method.

Techniques and technologies for the bioanalysis of Sativex®, metabolites and related compounds

Sativex® is an oromucosal spray indicated for the treatment of moderate-to-severe spasticity in multiple sclerosis and is also an effective analgesic for advanced cancer patients. Sativex contains Δ9-tetrahydrocannabinol (THC) and cannabidiol in an approximately 1:1 ratio. The increasing prevalence of medicinal cannabis products highlights the importance of reliable bioanalysis and re-evaluation of the interpretation of positive test results for THC, as legal implications may arise in workplace, roadside and sports drug testing situations. This article summarizes published research on the bioanalysis of THC and cannabidiol, with particular focus on Sativex. Common screening and confirmatory testing of blood, urine, oral fluid and hair samples are outlined. Correlations between matrices and current analytical pitfalls are also addressed.

Water-compatible imprinted pills for sensitive determination of cannabinoids in urine and oral fluid

A novel molecularly imprinted solid phase extraction (MISPE) methodology followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) has been developed using cylindrical shaped molecularly imprinted pills for detection of Δ(9)-tetrahydrocannabinol (THC), 11-nor-Δ(9)-tetrahydrocannabinol carboxylic acid (THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in urine and oral fluid (OF). The composition of the molecular imprinted polymer (MIP) was optimized based on the screening results of a non-imprinted polymer library (NIP-library). Thus, acrylamide as functional monomer and ethylene glycol dimethacrylate as cross-linker were selected for the preparation of the MIP, using catechin as a mimic template. MISPE pills were incubated with 0.5 mL urine or OF sample for adsorption of analytes. For desorption, the pills were transferred to a vial with 2 mL of methanol:acetic acid (4:1) and sonicated for 15 min. The elution solvent was evaporated and reconstituted in methanol:formic acid (0.1%) 50:50 to inject in LC-MS/MS. The developed method was linear over the range from 1 to 500 ng mL(-1) in urine and from 0.75 to 500 ng mL(-1) in OF for all four analytes. Intra- and inter-day imprecision were <15%. Extraction recovery was 50-111%, process efficiency 15.4-54.5% and matrix effect ranged from -78.0 to -6.1%. Finally, the optimized and validated method was applied to 4 urine and 5 OF specimens. This is the first method for the determination of THC, THC-COOH, CBN and CBD in urine and OF using MISPE technology.

Comparison of cannabinoid concentrations in oral fluid and whole blood between occasional and regular cannabis smokers prior to and after smoking a cannabis joint

A cross-over controlled administration study of smoked cannabis was carried out on occasional and heavy smokers. The participants smoked a joint (11% Δ9-tetrahydrocannabinol (THC)) or a matching placebo on two different occasions. Whole blood (WB) and oral fluid (OF) samples were collected before and up to 3.5 h after smoking the joints. Pharmacokinetic analyses were obtained from these data. Questionnaires assessing the subjective effects were administered to the subjects during each session before and after the smoking time period. THC, 11-hydroxy-THC (11-OH-THC) and 11-nor-9-carboxy-THC (THCCOOH) were analyzed in the blood by gas chromatography or liquid chromatography (LC)-tandem mass spectrometry (MS/MS). The determination of THC, THCCOOH, cannabinol (CBN), and Δ9-tetrahydrocannabinolic acid A (THC-A) was carried out on OF only using LC-MS/MS. In line with the widely accepted assumption that cannabis smoking results in a strong contamination of the oral cavity, we found that THC, and also THC-A, shows a sharp, high concentration peak just after smoking, with a rapid decrease in these levels within 3 h. No obvious differences were found between both groups concerning THC median maximum concentrations measured either in blood or in OF; these levels were equal to 1,338 and 1,041 μg/L in OF and to 82 and 94 μg/L in WB for occasional and heavy smokers, respectively. The initial WB THCCOOH concentration was much higher in regular smokers than in occasional users. Compared with the occasional smokers, the sensation of confusion felt by the regular smokers was much less while the feeling of intoxication remained almost unchanged.

THCCOOH concentrations in whole blood: are they useful in discriminating occasional from heavy smokers?

Some forensic and clinical circumstances require knowledge of the frequency of drug use. Care of the patient, administrative, and legal consequences will be different if the subject is a regular or an occasional cannabis smoker. To this end, 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THCCOOH) has been proposed as a criterion to help to distinguish between these two groups of users. However, to date this indicator has not been adequately assessed under experimental conditions. We carried out a controlled administration study of smoked cannabis with a placebo. Cannabinoid levels were determined in whole blood using tandem mass spectrometry. Significantly high differences in THCCOOH concentrations were found between the two groups when measured during the screening visit, prior to the smoking session, and throughout the day of the experiment. Receiver operating characteristic (ROC) curves were determined and two threshold criteria were proposed in order to distinguish between these groups: a free THCCOOH concentration below 3 µg/L suggested an occasional consumption (≤ 1 joint/week) while a concentration higher than 40 µg/L corresponded to a heavy use (≥ 10 joints/month). These thresholds were tested and found to be consistent with previously published experimental data. The decision threshold of 40 µg/L could be a cut-off for possible disqualification for driving while under the influence of cannabis. A further medical assessment and follow-up would be necessary for the reissuing of a driving license once abstinence from cannabis has been demonstrated. A THCCOOH level below 3 µg/L would indicate that no medical assessment is required.

Oral fluid cannabinoid concentrations following controlled smoked cannabis in chronic frequent and occasional smokers

Oral fluid (OF) is an alternative biological matrix for monitoring cannabis intake in drug testing, and drugged driving (DUID) programs, but OF cannabinoid test interpretation is challenging. Controlled cannabinoid administration studies provide a scientific database for interpreting cannabinoid OF tests. We compared differences in OF cannabinoid concentrations from 19 h before to 30 h after smoking a 6.8% THC cigarette in chronic frequent and occasional cannabis smokers. OF was collected with the Statsure Saliva Sampler™ OF device. 2D-GC-MS was used to quantify cannabinoids in 357 OF specimens; 65 had inadequate OF volume within 3 h after smoking. All OF specimens were THC-positive for up to 13.5 h after smoking, without significant differences between frequent and occasional smokers over 30 h. Cannabidiol (CBD) and cannabinol (CBN) had short median last detection times (2.5-4 h for CBD and 6-8 h for CBN) in both groups. THCCOOH was detected in 25 and 212 occasional and frequent smokers' OF samples, respectively. THCCOOH provided longer detection windows than THC in all frequent smokers. As THCCOOH is not present in cannabis smoke, its presence in OF minimizes the potential for false positive results from passive environmental smoke exposure, and can identify oral THC ingestion, while OF THC cannot. THC ≥ 1 μg/L, in addition to CBD ≥ 1 μg/L or CBN ≥ 1 μg/L suggested recent cannabis intake (≤13.5 h), important for DUID cases, whereas THC ≥ 1 μg/L or THC ≥ 2 μg/L cutoffs had longer detection windows (≥30 h), important for workplace testing. THCCOOH windows of detection for chronic, frequent cannabis smokers extended beyond 30 h, while they were shorter (0-24 h) for occasional cannabis smokers.

Simultaneous quantification of Δ(9)-tetrahydrocannabinol, 11-nor-9-carboxy-tetrahydrocannabinol, cannabidiol and cannabinol in oral fluid by microflow-liquid chromatography-high resolution mass spectrometry

Δ(9)-Tetrahydrocannabinol (THC) is the primary target in oral fluid (OF) for detecting cannabis intake. However, additional biomarkers are needed to solve interpretation issues, such as the possibility of passive inhalation by identifying 11-nor-9-carboxy-THC (THCCOOH), and determining recent cannabis smoking by identifying cannabidiol (CBD) and/or cannabinol (CBN). We developed and comprehensively validated a microflow liquid chromatography (LC)-high resolution mass spectrometry method for simultaneous quantification of THC, THCCOOH, CBD and CBN in OF collected with the Oral-Eze(®) and Quantisal™ devices. One milliliter OF-buffer solution (0.25mL OF and 0.5mL of Oral-Eze buffer, 1:3 dilution, or 0.75mL Quantisal buffer, 1:4 dilution) had proteins precipitated, and the supernatant subjected to CEREX™ Polycrom™ THC solid-phase extraction (SPE). Microflow LC reverse-phase separation was achieved with a gradient mobile phase of 10mM ammonium acetate pH 6 and acetonitrile over 10min. We employed a Q Exactive high resolution mass spectrometer, with compounds identified and quantified by targeted-MSMS experiments. The assay was linear 0.5-50ng/mL for THC, CBD and CBN, and 15-500pg/mL for THCCOOH. Intra- and inter-day and total imprecision were <10.8%CV and bias 86.5-104.9%. Extraction efficiency was 52.4-109.2%, process efficiency 12.2-88.9% and matrix effect ranged from -86 to -6.9%. All analytes were stable for 24h at 5°C on the autosampler. The method was applied to authentic OF specimens collected with Quantisal and Oral-Eze devices. This method provides a rapid simultaneous quantification of THCCOOH and THC, CBD, CBN, with good selectivity and sensitivity, providing the opportunity to improve interpretation of cannabinoid OF results by eliminating the possibility of passive inhalation and providing markers of recent cannabis smoking.