Adaptation of a Field Prototype Micro-GC to Biological Monitoring of Exposure and Health Status

Research Trainee: Jonathan Bryant-Genevier, PhD, Department of Environmental Health Sciences at the University of Michigan

Faculty Researcher: Edward T. Zellers, PhD, Professor of Chemistry and Environmental Health Sciences at the University of Michigan

This proposal seeks pilot funding to adapt a recently constructed (in-house) field prototype microfabricated gas chromatograph (μGC) to the analysis of breath and saliva for target indicators of exposure and health status relevant to occupational health. Although resurgent interest in non-invasive bio-monitoring of workers using these media is evident from the literature, current approaches rely on large, expensive instruments that are not suitable for routine operation by minimally trained operators.

Having a portable, turn-key instrument capable of identifying and quantifying biomarkers would allow the screening of workers at low cost in a matter of minutes in a field or clinical setting. The research proposed here will explore the feasibility of using this novel instrument for such applications using simulated breath and saliva matrices. For the exposure application, we will quantitatively analyze diacetyl (alone or together with several known metabolites), an insidious lung toxicant used in artificial butter flavor, currently under study by OSHA and ACGIH for establishment of exposure standards/guidelines. For the health status application, we will analyze a set of reported biomarkers of tuberculosis (TB) infection at clinically relevant concentrations. TB is responsible for millions of deaths per year; potential occupational health applications include monitoring TB among African miner populations and infection assessment of healthcare workers who treat TB patients. To avoid the use of human subjects, we will use synthetic breath formulations and a commercial synthetic saliva formation. The prototype instrument incorporates state-of-the-art features, including a multi-stage pretrap/ sampler/focuser, series-coupled separation columns with independent temperature programmed retention, and a detector comprising an integrated array of chemiresistor (CR) microsensors that provides pattern recognition of eluting vapors by chemometric analysis. Parts-per-trillion concentrations of target VOCs have been measured with this prototype in its first lab validation studies. This project will entail changing certain critical μGC components and materials to permit the analysis of VOCs in breath and saliva, optimizing analytical conditions, and demonstrating that the portable instrument can be used for clinical or field deployment. The project will provide critical project management experience for the post-doctoral lead investigator, will address priorities for improved exposure and risk assessment tools set forth in the most recent NORA agenda in manufacturing, mining and health-care sectors, and provide preliminary data to support full proposals to other organizations for follow-on funding.


Research trainee’s current position:
Jonathan Bryant-Genevier is currently still pursuing his PhD at the University of Michigan.