Climbazole – Determination of dihydroxyclimbazole and carboxyhydroxyclimbazole in urine by UPLC-MS/MS
Biomonitoring Method – Translation of the German version from 2026
Katja Küpper1 (Method development)Christoph Schmidtkunz1 (Method development)
Isabell Schönrath1 (Method development)
Wolfgang Gries1 (Method development)
Gabriele Leng1 (Method development)
Gerhard Scherer2 (External verification)
Max Scherer2 (External verification)
Kirsten Riedel2 (External verification)
Thomas Göen3 (Head of the working group “Analyses in Biological Materials” of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
Andrea Hartwig4 (Chair of the Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft)
MAK Commission5
1 Currenta GmbH & Co. OHG, CUR-SIT-ABG-GS-BLM – Institute for Biomonitoring, Chempark Building Q18, 51368 Leverkusen, Germany
2 ABF Analytisch-Biologisches Forschungslabor GmbH, Semmelweisstraße 5, 82152 Planegg, Germany
3 Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute and Outpatient Clinic of Occupational, Social, and Environmental Medicine, Henkestraße 9–11, 91054 Erlangen, Germany
4 Institute of Applied Biosciences, Department of Food Chemistry and Toxicology, Karlsruhe Institute of Technology (KIT), Adenauerring 20a, Building 50.41, 76131 Karlsruhe, Germany
5 Permanent Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area, Deutsche Forschungsgemeinschaft, Kennedyallee 40, 53175 Bonn, Germany
Abstract
The working group “Analyses in Biological Materials” of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified this analytical method for the determination of two important urinary metabolites of climbazole – dihydroxyclimbazole ((OH)2-climbazole) and carboxyhydroxyclimbazole (cx-OH-climbazole). For the quantitation of the analytes, enzymatic hydrolysis of the urine sample is followed by online SPE‑UPLC‑MS/MS. The two diastereomers of (OH)2-climbazole are resolved chromatographically, and thus quantified separately. On the other hand, the diastereomers of cx-OH-climbazole coelute in one single peak. Calibration is performed using calibration standards prepared in pooled urine and processed analogously to the samples to be analysed. (OH)2‑climbazole-D6 and cx‑OH‑climbazole-D6 are applied as internal standards. The method provides reliable and accurate analytical results, as shown by the good precision data with standard deviations no greater than 9.2%. Good accuracy data were obtained with a mean relative recovery in the range of 96.9–102%. The method is both selective and sensitive, and provides a quantitation limit of 0.5 μg/l for (OH)2‑climbazole (per diastereomer) and cx‑OH‑climbazole (sum of diastereomers), respectively. The method enables the determination of occupational and environmental exposure to climbazole.
