Urinary excretion of heptanones, heptanoles and 2,5-heptanedione after controlled acute exposure of volunteers to n-heptane
Autor: | Peter Kegel, Bernd Rossbach, Stephan Letzel |
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Rok vydání: | 2018 |
Předmět: |
Adult
Male Metabolite Urinary system Urine 010501 environmental sciences Urinalysis Toxicology 01 natural sciences Gas Chromatography-Mass Spectrometry Heptanes Excretion chemistry.chemical_compound Young Adult Biomonitoring Humans Biotransformation 0105 earth and related environmental sciences Creatinine Heptane Chromatography Inhalation Environmental Biomarkers 010401 analytical chemistry Solid Phase Extraction Reproducibility of Results General Medicine Ketones 0104 chemical sciences Renal Elimination chemistry Heptanol Environmental Monitoring |
Zdroj: | Toxicology letters. 298 |
ISSN: | 1879-3169 |
Popis: | A lack of well-established parameters and assessment values currently impairs biomonitoring of n-heptane exposure. Using controlled inhalation experiments, we collected information on urinary n-heptane metabolite concentrations and the time course of metabolite excretion. Relationships between external and internal exposure were analysed to investigate the suitability of selected metabolites to reflect n-heptane uptake. Twenty healthy, non-smoking males (aged 19-38 years, median 25.5) were exposed for 3 h to 167, 333 and 500 ppm n-heptane, each. Spot urine samples of the volunteers, collected before exposure and during the following 24 h, were analysed for heptane-2-one, 3-one, 4-one, 2,5-dione, 1-ol, 2-ol, 3-ol, and 4-ol using headspace solid phase dynamic extraction gas chromatography/mass spectrometry (HS-SPDE-GC/MS). Starting from median pre-exposure concentrations between0.5 (3-one) and 82.9 μg/L (4-one), exposure increased the concentrations for all parameters except for 4-one. Median post-exposure concentrations ranged up to 840.4 μg/L (2-ol) and decreased with half-lifes3 h after exposure. Non-parametric correlation analyses (n = 47, p 0.05) revealed weak to moderate associations of volume related metabolite excretion with external exposure for 2-one, 3-one and 2,5-dione (R = 0.332-0.753). Heptanol excretion was moderately associated with exposure (R ≥ 0.509) only after creatinine adjustment. Lacking association with external exposure impedes the use of 4-one as heptane biomarker, whereas 2-ol and 3-ol turned out to be sensitive indicators of exposure if creatinine correction is applied. By providing fundamental data on a panel of eight potential heptane metabolites, our study can help to promote biological monitoring of n-heptane exposure. |
Databáze: | OpenAIRE |
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