A method for quantification of volatile organic compounds in blood by SPME-GC–MS/MS with broader application: From non-occupational exposure population to exposure studies

• We described a modified method to detect volatile organic compounds in blood.
• The method can be used to detect blood VOCs in non-occupational exposure populations (ng/L levels).
• The method was further modified to detect blood VOCs in an exposure study (μg/L).
• Several factors must be taken into consideration during the determination of VOCs in blood.

Humans are continuously exposed to volatile organic compounds (VOCs) as these chemicals are ubiquitously present in most indoor and outdoor environments. In order to assess recent exposure to VOCs for population-based studies, VOCs are measured in the blood of participants. This work describes an improved method to detect 12 VOCs by head-space solid-phase microextraction gas chromatography coupled with isotope-dilution mass spectrometry in selected reaction monitoring mode (SPME-GC–MS/MS). This method was applied to the analysis of trihalomethanes, styrene, trichloroethylene, tetrachloroethylene and BTEX (benzene, toluene, ethylbenzene, m-xylene, p-xylene, o-xylene) in a population-based biomonitoring study (Canadian Health Measures Survey). The method showed good linearity (>0.990) in the range of 0.010–10 μg/L and detection limits between 0.007 and 0.027 μg/L, precision better than 25% and good accuracy (±25%) based on proficiency testing materials. Quality Control data among runs over a 7 month period showed %RSD between 14 and 25% at low levels (∼0.03 μg/L) and between 9 and 23% at high levels (∼0.4 μg/L). The method was modified to analyze samples from a pharmacokinetic study in which 5 healthy volunteers were exposed to single, binary and quaternary mixtures of CTEX (chloroform, ethylbenzene, toluene and m-xylene), thus the expected concentration in blood was 1 order of magnitude higher than those found in the general population. The method was modified by reducing the sample size (from 3 g to 0.5 g) and increasing the upper limit of the concentration range to 395 μg/L. Good linearity was found in the range of 0.13–395 μg/L for toluene and ethylbenzene and 0.20–609 μg/L for m/p-xylene. Quality control data among runs over the period of the study (n = 13) were found to vary between 7 and 25%.