PNNL

Abstract

A method for estimating the responses of polymer-coated acoustic wave vapor sensors has been developed. Polymer/gas partition coefficients, determined experimetally for at least 20-30 solute vapors by a simple gas chromatographic method, are used to construct linear solvation energy relationships that correlate partition coefficients on a given polymer with various solute solvation parameters. Since these parameters are known are for over 2000 compounds, it is possible to estimate polymer/gas partition coefficients values for thousands of vapor/polymer pairs. It is shown how these partition coefficients can, in turn, be used to estimate acoustic wave vapor sensor responses. Comparisions of predicted surface acoustic wave vapor sensor sensitivities with observed responses confirm the general vadality of the approach. The approach can be used to select polymers offering the best sensitivities for particular vapors. Limits of detection have been calculated and compared with permissible exposure limits and threshold limit values for a variety of vapors of interest in environmental remediation and occupational safety. These results indicate that polymer-coated surface acoustic wave vapors sensors are capable of detecting the majority of the vapors considered at concentrations of interest.