Determination of blood:air, urine:air and plasma:air partition coefficients of selected microbial volatile organic compounds.

ABSTRACT

Partition coefficients (PCs) are essential parameters for understanding the toxicokinetics of chemicals in the human body since they are used in the description of different processes of absorption, distribution, and excretion in physiologically based pharmacokinetic (PBPK) models used in chemical exposure and risk assessment. The goal of this study was to determine urineair, bloodair and plasmaair partition coefficients (PCs) of microbial volatile organic compounds (mVOCs) previously selected as having high potential as biomarkers of indoor mold exposure. To achieve this goal, the vial-equilibration technique was used, and quantification was performed using headspace gas chromatography tandem mass spectrometry (HS-GC-MS/MS) analysis. Matrixair PCs of 19 different mVOCs have been successfully determined and their values ranged between 14 and 3586 for urineair, 78 and 4721 for bloodair and 64 and 5604 for plasmaair PCs. Waterair PCs were also determined, and their values varied between 16 and 2210, showing a good correlation with urineair PCs for 17 compounds of the selected mVOCs (R2 = 0.97, slope close to unity) indicating that waterair PCs below 103 may be a good surrogate for urineair PCs. All studied mVOCs have high bloodair PCs (greater than 78) indicating strong pulmonary uptake. Due to their high bloodurine PCs, some mVOCs may be more easily measured in blood than in urine. This work is an important preliminary step toward the use of mVOCs as potential biomarkers of indoor mold exposure. The data obtained in this study will help to determine the most appropriate matrix to use in this biomonitoring approach and will eventually facilitate the development of PBPK models for these chemicals.