Testing the Performance of a Novel Vapor Monitoring Instrument

Research Trainee: Meng-Da Hsieh, PhD Student, Dept. of Environmental Health Sciences at the University of Michigan

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

Laboratory testing and performance modeling of a novel, personal direct-reading instrument capable of identifying and quantifying organic vapors at low-ppm concentrations was performed. Marketed under the name VaporLab, this instrument was designed as a “vapor comparator”. The tested instrument weighs less than 1.5 lbs and is about the size of a standard personal sampling pump. It employs an array of four polymer-coated surface-acoustic-wave (SAW) microsensors and a miniature pre-concentrator for vapor detection. The patterns of responses obtained from the array are used to identify specific vapors or vapor mixtures and can be used to discriminate among the components of certain simple mixtures.

Following some modifications to the instrument and initial laboratory calibrations, side-by-side measurements with standard methods were performed in dynamic controlled test-atmospheres. Results demonstrated the capability for direct analysis of certain vapors and vapor mixtures at concentrations relevant to occupational exposure and compliance monitoring applications. In conjunction with the work just described, in-house pattern recognition software routines coupled with Monte Carlo simulations were used to define generalized performance limits/capabilities of the instrument.

Current personal monitoring instrumentation cannot provide selective analysis of multiple organic vapors. This research has shown that the new instrument is capable of providing improved personal exposure data needed for characterizing the distributions of organic-vapor exposures in the workplace and determining compliance with accepted exposure limits. This research has addressed on-going needs identified in the NIOSH National Occupational Research Agenda (NORA) in the areas of emerging technologies and exposure assessment methods.

 

Publications resulting from this project:
Hsieh M, Zellers ET. Adaptation and evaluation of a hand-held electronic nose for selective multi-vapor analysis. J Occup and Environ Hyg. 2004;1:149-160.

Grants resulting from this project:
NIOSH/CDC. R01-OH003692-01 (PI: Zellers). Microanalytical System for Indoor VOC Monitoring. 4/1/02-3/31/05.

 

Research trainee’s current position:
Meng-da Hsieh received his PhD in 2003 and is currently a Senior Specialist at AbbVie.