METHOD FOR ESTIMATING POLYMER-COATED ACOUSTIC-WAVE VAPOR SENSOR RESPONSES

A method for estimating the responses of polymer-coated acoustic wave vapor sensors has been developed. Polymer/gas partition coefficients, determined experimentally for at least 20-30 solute vapors by a simple gas chromatographic method, are used to construct linear solvation en ergy relationships that correlate partition coefficients on a given po lymer with various solute solvation parameters, Since these parameters are known for over 2000 compounds, it is possible to estimate polymer /gas partition coefficient values for thousands of vapor/polymer pairs . It is shown how these partition coefficients can, in turn, be used t o estimate acoustic wave vapor sensor responses. Comparisons of predic ted surface acoustic wave vapor sensor sensitivities with observed res ponses confirm the general validity of the approach. The approach can be used to select polymers offering the best sensitivities for particu lar 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 sa fety. These results indicate that polymer-coated surface acoustic wave vapor sensors are capable of detecting the majority of the vapors con sidered at concentrations of interest.