Dielectric barrier discharge-induced chemiluminescence: potential application as GC detector

Atmospheric pressure dielectric barrier discharge (DBD) plasma can be used to split low molecular weight organic compounds, and the DBD-split/excited species can be swept into luminol solution to induce chemiluminescence (CL) emission. Based on this observation, a novel optical detector was proposed and preliminarily tested as a potential gas chromatographic (GC) detector in this work. The advantages of this new type of detector include the following: direct detection, fast response, high sensitivity, versatility (sensitive to a broad range of volatile organic compounds), simple and easy instrumentation, compactness (3.0 mm i.d. x 4.0 mm o.d. x 20 mm length of the DBD device), and low power (less than 5 W). Twelve volatile organic compounds, including methanol, ethanol, propanol, formaldehyde, acetaldehyde, benzene, dichloromethane, trichloromethane, tetrachloromethane, tetrahydrofuran, carbon bisulfide, and ethyl ether, were tested with this detector, and each of them produced a large signal. It was found that the CL signal was proportional to the analyte concentration and affected by the DBD parameters. Under the optimized experimental conditions, the limits of detection down to the tens of nanogram level were achieved for methanol, ethanol, propanol, formaldehyde, and acetaldehyde. It was then preliminarily tested as a GC detector for the separation of formaldehyde, ethanol, and propanol. This is the new application of DBD in analytical chemistry, and CL was for the first time generated in this way. The new detector can be a potential GC detector suitable for a wide range of volatile organic compounds.