Tebuconazole and penconazole - Determination of TEB-OH, TEB-COOH, PEN-OH, and PEN-COOH in urine by LC-MS/MS: Biomonitoring Method - Translation of the German version from 2026.

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 biomonitoring method for the measurement of the most important urinary metabolites of the triazole fungicides tebuconazole and penconazole. Specifically, this method determines (RS)-5-(4-chlorophenyl)-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)-1,3-pentanediol (TEB-OH) and (RS)-5-(4-chlorophenyl)-2,2-dimethyl-3-(1H-1,2,4-triazol-1-ylmethyl)-3-olpentanoic acid (TEB-COOH) as well as 4-(2,4-dichlorophenyl)-5-[1,2,4]-triazol-1-ylpentanol (PEN-OH) and 4-(2,4-dichlorophenyl)-5-[1,2,4]-triazol-1-ylpentanoic acid (PEN-COOH) in urine. After adding isotope-labelled internal standards, the samples are enzymatically hydrolysed to release the analytes from the glucuronide and sulfate conjugates. After online purification, the analytes are separated by liquid chromatography and analysed using tandem mass spectrometry. Calibration is performed using calibration standards prepared in pooled urine and processed analogously to the samples to be analysed. The method provides reliable and accurate analytical results, as shown by the good precision data with standard deviations in the range of 0.1-10.7%. Good accuracy data were obtained with mean relative recoveries in the range of 100-107%. The method is selective, sensitive, and provides quantitation limits of 0.3 μg/l for TEB-OH and TEB-COOH and of 1.0 μg/l for PEN-OH and PEN-COOH.