Determination of volatile organic compounds in air by a surface acoustic wave array

Abstract

This article reports the design and performance of a portable volatile organic compound detection system implemented with a surface acoustic wave array. The system employed electrospray technology for the determination of acetone and methanol. The novel part of this study was the design of the 433MHz surface acoustic wave array. The sensor oscillators were operated at higher frequencies to reduce space and power consumption. The higher frequency also improved the response resolution; however, it created problems including interferences, crosstalk, signal degradation, and noise. Crosstalk was the most important problem and was minimized by the operation of one sensor at a time while the others were muted. Analog and digital circuitry served as the transducer to obtain analyte signals that were processed to produce bar and principal component analysis plots. The system was extensively tested and good results were obtained for qualitative and quantitative measurements.