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Updated: Dec 13, 2025

Ultrasonic-Assisted Extraction of Cannabidiolic Acid from Cannabis Biomass
Published on: May 27, 2022
Determination of cannabinoids in plasma using salting-out-assisted liquid-liquid extraction followed by LC-MS/MS
Cristiane Pires da Silva1,2,3, Luiz Paulo Pugen Dalpiaz1, Fernando Engel Gerbase1,2
1Laboratory of Analytical Toxicology, Feevale University, Novo Hamburgo, Brazil.
Abstract:
The detection of the markers of Cannabis consumption in biological specimens is an important task for drug testing laboratories in varous contexts. A simple assay combining salting-out assisted liquid-liquid extraction sample preparation and LC-MS/MS analysis was applied to the measurement of Δ9 -tetrahydrocannabinol, 11-nor-9-carboxy-Δ9 -tetrahydrocannabinol (THC-COOH), 11-hydroxy-Δ9 -tetrahydrocannabinol, cannabinol and cannabidiol concentrations in 100 μl plasma specimens. The assay had linearity of 1-100 ng ml-1 for THC-COOH and 0.5-50 ng ml-1 for the other tested cannabinoids. Assay validation criteria were fulfilled. Extraction yields (88.7-97.3%) and internal-standard correct matrix effects (-9.6 to +5.4%) were acceptable. The assay was applied to 238 clinical specimens from trauma patients, with 19 samples presenting quantifiable concentrations of at least one of the target compounds. The developed assay is a simple and efficient strategy for simultaneous measurement of Δ9 -tetrahydrocannabinol, THC-COOH, 11-hydroxy-Δ9 -tetrahydrocannabinol, cannabinol and cannabidiol concentrations in plasma specimens.

