title: Simultaneous quantification of delta-9-THC, THC-acid A, CBN and CBD in seized drugs using HPLC-DAD.
abstract: An HPLC-DAD method for the quantitative analysis of Δ(9)-tetrahydrocannabinol (THC), Δ(9)-tetrahydrocannabinolic acid-A (THCA-A), cannabidiol (CBD), and cannabinol (CBN) in confiscated cannabis products has been developed, fully validated and applied to analyse seized cannabis products. For determination of the THC content of plant material, this method combines quantitation of THCA-A, which is the inactive precursor of THC, and free THC. Plant material was dried, homogenized and extracted with methanol by ultrasonication. Chromatographic separation was achieved with a Waters Alliance 2695 HPLC equipped with a Merck LiChrospher 60 RP-Select B (5μm) precolumn and a Merck LiChroCart 125-4 LiChrospher 60 RP-Select B (5μm) analytical column. Analytes were detected and quantified using a Waters 2996 photo diode array detector. This method has been accepted by the public authorities of Switzerland (Bundesamt für Gesundheit, Federal Office of Public Health), and has been used to analyse 9092 samples since 2000. Since no thermal decarboxylation of THCA-A occurs, the method is highly reproducible for different cannabis materials. Two calibration ranges are used, a lower one for THC, CBN and CBD, and a higher one for THCA-A, due to its dominant presence in fresh plant material. As provider of the Swiss proficiency test, the robustness of this method has been tested over several years, and homogeneity tests even in the low calibration range (1%) show high precision (RSD≤4.3%, except CBD) and accuracy (bias≤4.1%, except CBN).
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland.
authors.forename: Lars
authors.initials: L
authors.lastname: Ambach
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland.
authors.forename: Franziska
authors.initials: F
authors.lastname: Penitschka
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland.
authors.forename: Alain
authors.initials: A
authors.lastname: Broillet
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland.
authors.forename: Stefan
authors.initials: S
authors.lastname: König
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland. Electronic address: Wolfgang.Weinmann@irm.unibe.ch.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Weinmann
authors.affiliation: Institute of Forensic Medicine, University of Bern, Bühlstrasse 20, CH 3012 Bern, Switzerland.
authors.forename: Werner
authors.initials: W
authors.lastname: Bernhard
mesh_terms: D002185:Cannabidiol / Q000032:analysis; D002187:Cannabinol / Q000032:analysis; D002188:Cannabis / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D013759:Dronabinol / Q000031:analogs & derivatives / Q000032:analysis; D010936:Plant Extracts / Q000737:chemistry; D011619:Psychotropic Drugs / Q000032:analysis*
chemical_list: D010936:Plant Extracts; D011619:Psychotropic Drugs; D002185:Cannabidiol; D013759:Dronabinol; D002187:Cannabinol; C025351:delta(9)-tetrahydrocannabinolic acid
keywords: HPLC–DAD; Hashish; Marihuana; Seized drugs; THC; THC-acid-A