Colorimetric Readout based Photoionization Detector for Gas Chromatographs

This paper presents a new scheme for readout of a photoionization detector (PID) that utilizes the ionization luminescence of target gases in helium plasma to generate an output signal. Our signal readout method is based on processing the recorded video and correlating the light peak intensity with the sample injection time and concentration. We successfully demonstrated the feasibility of a colorimetric readout-based photoionization detector coupled with a gas chromatography column by detecting a mixture of non-polar compounds (alkanes) and two polar compounds (acetone and ethanol). The detection limit for our first-generation device was calculated to be ~118 ng for acetone and around 26 ng for ethanol.