Direct quantification of cannabinoids and cannabinoid glucuronides in whole blood by liquid chromatography–tandem mass spectrometry

Abstract

The first method for quantifying cannabinoids and cannabinoid glucuronides in whole blood by liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed and validated. Solid-phase extraction followed protein precipitation with acetonitrile. HPLC separation was achieved in 16 min via gradient elution. Electrospray ionization was utilized for cannabinoid detection; both positive (Δ9-tetrahydrocannabinol [THC], cannabinol [CBN]) and negative (11-hydroxy-THC [11-OH-THC], 11-nor-9-carboxy-THC [THCCOOH], cannabidiol [CBD], THC-glucuronide and THCCOOH glucuronide) polarity were employed with multiple reaction monitoring. Calibration by linear regression analysis utilized deuterium-labeled internal standards and a 1/x2 weighting factor, yielding R2 values > 0.997 for all analytes. Linearity ranged from 0.5–50 μg/L (THC-glucuronide), 1.0–100 μg/L (THC, 11-OH-THC, THCCOOH, CBD and CBN) and 5.0–250 μg/L (THCCOOH-glucuronide). Imprecision was < 10.5% CV, recovery was > 50.5% and bias within ± 13.1% of target for all analytes at three concentrations across the linear range. No carryover, endogenous or exogenous interferences were observed. This new analytical method should be useful for quantifying cannabinoids in whole blood and further investigating cannabinoid glucuronides as markers of recent cannabis intake.

Controlled Cannabis Vaporizer Administration: Blood and Plasma Cannabinoids with and without Alcohol

“…We quantified blood and plasma cannabinoids by a previously published LC-MS/MS method (21 ). Briefly, 0.5 mL blood or plasma was protein-precipitated with icecold acetonitrile, and supernatants were diluted and solid-phase extracted with Bond-Elut Plexa cartridges (Agilent Technologies).…”

Development of a rapid column-switching LC-MS/MS method for the quantification of THCCOOH and THCCOOH-glucuronide in whole blood for assessing cannabis consumption frequency

“…Numerous analytical methods for the quantification of THC and its metabolites in biological fluids have been developed, which are mostly based on gas chromatography (GC) or liquid chromatography (LC) coupled to mass spectrometry (MS) [23,24]. However, the direct and simultaneous determination of THCCOOH and its glucuronide by GC-MS is not possible as glucuronides are thermally unstable and non-volatile [25,26]. To quantify THCCOOHglucuronide by GC-MS, free THCCOOH is analyzed first and then the glucuronide is hydrolyzed to measure total THCCOOH.…”

“…The use of LC-MS/MS eliminates the need of costly and time-consuming alkaline and/ or enzymatic glucuronide hydrolysis, enabling direct measurement of free and glucuronidated THCCOOH. As native and isotopically labeled THCCOOH-glucuronide standards have become available only recently, few LC-MS/MS for quantifying THCCOOH-glucuronide in biological fluids exist [25,[29][30][31][32][33]. Schwope et al [25] and Gronewold et al [31] reported the only two existing methods for simultaneously measuring free and glucuronidated THCCOOH in whole blood, along with free and glucuronidated THC, 11-OH-THC, cannabinol and cannabidiol.…”

“…As native and isotopically labeled THCCOOH-glucuronide standards have become available only recently, few LC-MS/MS for quantifying THCCOOH-glucuronide in biological fluids exist [25,[29][30][31][32][33]. Schwope et al [25] and Gronewold et al [31] reported the only two existing methods for simultaneously measuring free and glucuronidated THCCOOH in whole blood, along with free and glucuronidated THC, 11-OH-THC, cannabinol and cannabidiol. Sample preparation consisted of protein precipitation followed by solid phase extraction [25] or liquid-liquid extraction [31] and chromatographic separation of the analytes was accomplished in 16 min and 10 min, respectively.…”

“…Schwope et al [25] and Gronewold et al [31] reported the only two existing methods for simultaneously measuring free and glucuronidated THCCOOH in whole blood, along with free and glucuronidated THC, 11-OH-THC, cannabinol and cannabidiol. Sample preparation consisted of protein precipitation followed by solid phase extraction [25] or liquid-liquid extraction [31] and chromatographic separation of the analytes was accomplished in 16 min and 10 min, respectively. In this work, a validated column-switching LC-MS/MS method for the direct and simultaneous quantification of THCCOOH and THCCOOH-glucuronide in whole blood is reported.…”