Determination of THC and THC‐COOH in Dried Capillary Blood Spots and Comparison to Venous Blood of Recreational Cannabis Consumers in a Pilot Study
-tetrahydrocannabinol (THC-COOH). The linear ranges of the LC-MS/MS method are 0.5-20 ng/mL for THC and 1.25-100 ng/mL for THC-COOH with good precision and accuracy. Concentrations of THC and THC-COOH in DBS from capillary blood were compared to venous blood concentrations based on 159 blood samples retrieved from a study including recreational cannabis users. THC-COOH concentrations in DBS were in close agreement with venous blood concentrations with a median capillary DBS/venous blood ratio of 1.09 (mean 1.10 ± 0.21), whilst THC concentrations in capillary blood were higher than venous blood concentrations with a median ratio of 2.11 (mean 16.6 ± 87.9) (after exclusion of outliers: 1.84 [mean 2.57 ± 1.93]), and the THC concentration ratio capillary DBS/venous blood showed a larger variability, ranging from 0.75 to 722 (0.75 to 8.18 after exclusion of outliers).
Authors
- Willi Schirmer (ORCID: https://orcid.org/0009-0004-5579-2217)
- Wolfgang Weinmann (ORCID: https://orcid.org/0000-0001-8659-1304)
- Andreas Längin
- Reto Auer (ORCID: https://orcid.org/0000-0003-4222-4849)
- Matthias Bantle (ORCID: https://orcid.org/0000-0001-9210-2802)
- Lena Zwicker (ORCID: https://orcid.org/0000-0003-2775-9239)
- Thomas Wüthrich
- Joel Bruegger (ORCID: https://orcid.org/0009-0009-7199-4528)
Institutions
- University of Bern (CH)
- Centre universitaire de médecine générale et santé publique, Lausanne (CH)
Publication Details
- Journal
- Drug Testing and Analysis
- Published
- 2026-05-12
- DOI
- https://doi.org/10.1002/dta.70085
- Primary Topic
- Forensic Toxicology and Drug Analysis
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung